Multilayer coil component and method of manufacturing multilayer coil component

Abstract

To provide a multilayer coil component which reduces the disconnection risk of a lead-out connection part, and a manufacturing method thereof.SOLUTION: A multilayer coil component 1 comprises a laminate 10, in which a plurality of insulation layers 31 are laminated and which includes an internal electrode, and first and second external electrodes 21 and 22 which are electrically connected to the internal electrode. The internal electrode includes: a coil 30 which is formed by electrically connecting a plurality of coil conductors 32 laminated together with the insulation layers 31; a first lead-out conductor 41 which connects the coil and the first external electrode; and a second lead-out conductor 42 which connects the coil and the second external electrode. The first and second lead-out conductors extend in a lamination direction L of the insulation layers. When a coil conductor directly connected with the first lead-out conductor is defined as a first coil conductor 132a and a coil conductor directly connected with the second lead-out conductor is defined as a second coil conductor 132d in the coil conductors, pore area rates of the first and second lead-out conductors and the first and second coil conductors are respectively 1.00% or more to 11.00% or less.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] For example, Patent Document 1 discloses a multilayer electronic component in which a coil is formed inside by laminating coil conductors and insulating layers made of magnetic or non-magnetic materials, and which has terminal electrodes on both ends in the stacking direction, with the terminal electrode on at least one end connected to the end of the coil inside the laminate via a conductor-filled through hole provided in one or more insulating layers and an extraction electrode provided so as to cover the end of the through hole, in which the area of ​​the extraction electrode is set to be three times or more the cross-sectional area of ​​the through hole and one-third or less of the area of ​​the coil when the laminate is viewed transparently in the stacking direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-15918 Summary of the Invention [Problem to be solved by the invention]

[0004] In multilayer inductors (multilayer coil components), there is a demand for improved connectivity between the internal and external electrodes in the lead-out section.

[0005] However, in a multilayer coil component with horizontally wound electrodes in which external electrodes are drawn out to both ends of the insulating layers in the stacking direction, as described in Patent Document 1, the transition portion (also called the lead connection portion) between the coil conductor and the lead electrode (also called the lead conductor) is bent, and there is a problem in that this bent portion is prone to breakage.

[0006] This is thought to be due to the fact that when the conductor paste used to form the coil conductor and extraction electrode is fired, air bubbles (pores) form inside the conductor paste, and that the air bubbles generated inside the conductor paste are attracted outward at the extraction electrode and its vicinity. In other words, since there is no external electrode and the extraction electrode is exposed during firing, it is thought that bubbles generated in the coil conductor near the exposed part of this extraction electrode are attracted outward, concentrating at the bend (extraction connection part) where the coil conductor and extraction electrode change over, causing a break in the extraction connection part.

[0007] The present invention has been made to solve the above problems, and an object of the present invention is to provide a laminated coil component and a method for manufacturing a laminated coil component that can reduce the risk of disconnection at lead-out connections. [Means for solving the problem]

[0008] The laminated coil component of the present invention comprises a laminate formed by stacking a plurality of insulating layers and having an internal electrode, and first and second external electrodes electrically connected to the internal electrodes, wherein the internal electrodes include a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layers, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, wherein the first lead conductor and the second lead conductor extend in the stacking direction of the insulating layers, and wherein, when the coil conductor directly connected to the first lead conductor is defined as the first coil conductor and the coil conductor directly connected to the second lead conductor is defined as the second coil conductor, the pore area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are 1.00% or more and 11.00% or less, respectively.

[0009] A method for manufacturing a laminated coil component according to a first embodiment of the present invention includes: a laminate formed by laminating a plurality of insulating layers and having internal electrodes; and first and second external electrodes electrically connected to the internal electrodes, wherein the internal electrodes include a coil formed by electrically connecting a plurality of coil conductors laminated together with the insulating layers, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, wherein the first lead conductor and the second lead conductor extend in a lamination direction of the insulating layers, the method comprising the steps of: preparing ceramic green sheets containing a ceramic material; and depositing a conductor paste on a plurality of the ceramic green sheets. the step of stacking a plurality of the ceramic green sheets on which the conductor paste layers have been formed to produce an unfired laminate having an unfired coil built in; and the step of firing the unfired laminate to produce a laminate, wherein, of the coil conductors, the coil conductor directly connected to the first draw conductor is defined as the first coil conductor and the coil conductor directly connected to the second draw conductor is defined as the second coil conductor, the PVC of the conductor paste for the first coil conductor, the second coil conductor, the first draw conductor and the second draw conductor is 45.00% or more and 55.00% or less.

[0010] A method for manufacturing a laminated coil component according to a second embodiment of the present invention includes a laminate formed by stacking a plurality of insulating layers and having internal electrodes, and first and second external electrodes electrically connected to the internal electrodes, wherein the internal electrodes include a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layers, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, wherein the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, the method comprising the steps of: preparing ceramic green sheets containing a ceramic material; and printing a conductive paste on a plurality of the ceramic green sheets to print the coil conductors, the first lead conductor and / or the second lead conductor. The method includes a printing step of forming a conductor paste layer that will become an output conductor, a step of stacking a plurality of the ceramic green sheets on which the conductor paste layer is formed to produce an unfired laminate having an unfired coil embedded therein, and a step of firing the unfired laminate to produce a laminate, wherein, when, among the coil conductors, the coil conductor that is directly connected to the first output conductor is defined as the first coil conductor and the coil conductor that is directly connected to the second output conductor is defined as the second coil conductor, the conductor paste for the first coil conductor, the second coil conductor, the first output conductor and the second output conductor contains metal powder produced by a method other than water atomization, and the conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor contains metal powder produced by water atomization. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a laminated coil component and a method for manufacturing a laminated coil component that can reduce the risk of breakage of lead-out connections. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view schematically illustrating an example of a laminated coil component according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view schematically showing an example of a laminate constituting the laminated coil component shown in FIG. [Figure 3] FIG. 3 is a perspective side view schematically showing an example of the internal structure of a laminate constituting the laminated coil component shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view schematically illustrating an example of a cross section of the laminated coil component shown in FIG. 1 taken along line A1-A1. [Figure 5] FIG. 5 is a cross-sectional view schematically illustrating an example of a cross section of the laminated coil component shown in FIG. 1 taken along line A2-A2. [Figure 6] FIG. 6 is a cross-sectional view schematically showing an example of a laminated coil component that does not satisfy the features of the present invention. [Figure 7] FIG. 7 is an exploded perspective view schematically showing an example of a laminate constituting an example of a laminate coil component according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a side view schematically showing, in a see-through manner, the state of pores in the internal electrodes of the laminated coil component including the laminate shown in FIG. [Figure 9] FIG. 9 is a perspective view schematically illustrating an example of a laminated coil component according to a third embodiment of the present invention. [Figure 10] FIG. 10 is an exploded perspective view schematically showing an example of a laminate constituting the laminated coil component shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view schematically illustrating an example of a cross section of the laminated coil component shown in FIG. 9 taken along line A3-A3. DETAILED DESCRIPTION OF THE INVENTION

[0013] The laminated coil component and the method for manufacturing the laminated coil component of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate without departing from the gist of the present invention. Furthermore, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0014] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product. In the drawings, the same or equivalent parts will be designated by the same reference numerals. In addition, the same elements will be designated by the same reference numerals in each drawing, and duplicate explanations will be omitted.

[0015] In this specification, terms indicating the relationship between elements (e.g., "parallel," "orthogonal," etc.) and terms indicating the shape of elements not only mean the literal and strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[0016] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and only differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0017] [Multilayer coil components] The laminated coil component of the present invention comprises a laminate formed by stacking a plurality of insulating layers and having an internal electrode, and first and second external electrodes electrically connected to the internal electrodes, wherein the internal electrodes include a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layers, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, wherein the first lead conductor and the second lead conductor extend in the stacking direction of the insulating layers, and wherein, when the coil conductor directly connected to the first lead conductor is defined as the first coil conductor and the coil conductor directly connected to the second lead conductor is defined as the second coil conductor, the pore area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are 1.00% or more and 11.00% or less, respectively.

[0018] FIG. 1 is a perspective view schematically illustrating an example of a laminated coil component according to a first embodiment of the present invention. The laminated coil component 1 shown in Fig. 1 includes a laminate (element body) 10, and a first external electrode 21 and a second external electrode 22 provided on the outer surface of the laminate 10. The laminate 10 has a rectangular parallelepiped shape with six sides. The configuration of the laminate 10 will be described later; it is formed by stacking a plurality of insulating layers in the stacking direction, and is internally provided with a first lead conductor, a second lead conductor, and a coil, which are internal electrodes. The first external electrode 21 and the second external electrode 22 are electrically connected to the coil via the first lead conductor and the second lead conductor, respectively.

[0019] In the laminated coil component and laminate in this specification, the length direction, height direction, and width direction are defined as the L direction, T direction, and W direction in Fig. 1. Here, the length direction L, height direction T, and width direction W are perpendicular to each other. Here, the length direction L is parallel to the stacking direction.

[0020] As shown in FIG. 1, the laminate 10 has a first end face 11 and a second end face 12 facing in a longitudinal direction L, a first main face 13 and a second main face 14 facing in a height direction T perpendicular to the longitudinal direction L, and a first side face 15 and a second side face 16 facing in a width direction W perpendicular to the longitudinal direction L and the height direction T.

[0021] Although not shown in Fig. 1, the corners and ridges of the laminate 10 are preferably rounded. A corner is a portion where three surfaces of the laminate intersect, and a ridge is a portion where two surfaces of the laminate intersect.

[0022] For example, as shown in FIG. 1, the first external electrode 21 covers the entire first end face 11 of the laminate 10 and extends from the first end face 11 to cover a portion of the first main face 13, a portion of the second main face 14, a portion of the first side face 15, and a portion of the second side face 16.

[0023] For example, as shown in FIG. 1, the second external electrode 22 covers the entire second end face 12 of the laminate 10 and extends from the second end face 12 to cover a portion of the first main face 13, a portion of the second main face 14, a portion of the first side face 15, and a portion of the second side face 16.

[0024] When the laminated coil component 1 having the first external electrodes 21 and the second external electrodes 22 arranged as described above is mounted on a substrate, any one of the first main surface 13, the second main surface 14, the first side surface 15, and the second side surface 16 of the laminate 10 becomes the mounting surface.

[0025] However, it is sufficient that the first external electrode 21 extends from at least a part of the first end face 11 of the multilayer body 10 to the mounting surface of the multilayer body 10 .

[0026] Similarly, the second external electrode 22 may extend from at least a portion of the second end surface 12 of the laminate 10 to the mounting surface of the laminate 10 .

[0027] The first external electrode 21 and the second external electrode 22 may each have a single-layer structure or a multi-layer structure.

[0028] When the first external electrode 21 and the second external electrode 22 each have a single-layer structure, examples of the constituent material of each external electrode include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0029] When the first external electrode 21 and the second external electrode 22 each have a multi-layer structure, each external electrode may have, in order from the surface side of the laminate 10, for example, a base electrode layer containing Ag, a Ni coating, and a Sn coating.

[0030] The size of the laminated coil component of the present invention is not particularly limited, but is preferably 0603 size, 0402 size, or 1005 size.

[0031] FIG. 2 is an exploded perspective view schematically showing an example of a laminate constituting the laminated coil component shown in FIG.

[0032] 2, the laminate 10 is configured by stacking a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in a stacking direction (here, length direction L) from a first end face 11 side toward a second end face 12 side of the laminate 10. Hereinafter, the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f will also be collectively referred to as insulating layers 31.

[0033] In this specification, the direction in which the insulating layers constituting the laminate are stacked is referred to as the stacking direction.

[0034] In FIG. 2, insulating layer 31e is disposed on the lower side in the stacking direction (the first end face 11 side of the laminate 10), and insulating layer 31f is disposed on the upper side in the stacking direction (the second end face 12 side of the laminate 10).

[0035] The insulating layers 31 may be made of, for example, a magnetic material such as a ferrite material.

[0036] The insulating layers 31a, 31b, 31c, and 31d are provided with coil conductors 32a, 32b, 32c, and 32d, and via conductors 33a, 33b, 33c, and 33d, respectively. The insulating layer 31e is provided with a via conductor 33e and a land 35e. The insulating layer 31f is provided with a via conductor 33f and a land 35f. The insulating layer 31e may be a single layer or two or more layers. Similarly, the insulating layer 31f may be a single layer or two or more layers. Hereinafter, the coil conductors 32a, 32b, 32c, and 32d will also be collectively referred to as coil conductors 32.

[0037] Coil conductors 32a, 32b, 32c, and 32d are provided on the main surfaces of insulating layers 31a, 31b, 31c, and 31d, respectively, and are stacked together with insulating layers 31a, 31b, 31c, 31d, 31e, and 31f. In Fig. 2, each coil conductor 32 has a 3 / 4 turn shape, and four insulating layers 31 arranged in this order, 31a, 31b, 31c, and 31d, form one unit (three turns), which are repeatedly stacked.

[0038] The coil conductors 32a, 32b, 32c, and 32d each include an annular winding portion 34a, 34b, 34c, and 34d that is partially missing, leaving a gap, and lands 35a, 35b, 35c, and 35d. Lands 35a, 35b, 35c, and 35d are provided at both ends of the winding portion 34a, 34b, 34c, and 34d, respectively. Hereinafter, the winding portions 34a, 34b, 34c, and 34d will be collectively referred to as winding portion 34.

[0039] Via conductors 33a, 33b, 33c, 33d, 33e, and 33f are provided to penetrate insulating layers 31a, 31b, 31c, 31d, 31e, and 31f, respectively, in the stacking direction. Hereinafter, via conductors 33a, 33b, 33c, 33d, 33e, and 33f will also be collectively referred to as via conductors 33.

[0040] Lands 35e and 35f are provided directly above via conductors 33e and 33f, respectively. The widths of lands 35a, 35b, 35c, 35d, 35e, and 35f are preferably slightly larger than the line widths of winding portions 34a, 34b, 34c, and 34d. Hereinafter, lands 35a, 35b, 35c, 35d, 35e, and 35f will also be collectively referred to as lands 35.

[0041] Examples of materials that can be used to form each coil conductor 32 including the winding portion 34 and the land 35, and each via conductor 33 include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0042] The insulating layers 31a, 31b, 31c, 31d, 31e, and 31f configured as described above are stacked in the stacking direction. This forms the laminate 10, and the coil conductors 32a, 32b, 32c, and 32d are electrically connected via via conductors 33a, 33b, 33c, and 33d. As a result, a solenoid coil having a coil axis parallel to the stacking direction is formed within the laminate 10.

[0043] Furthermore, the via conductor 33a provided in the insulating layer 31a on which the coil conductor 32 closest to the first end face 11 is provided, the via conductor 33e, and the land 35e form a first extension conductor within the laminate 10 and are exposed at the first end face 11 of the laminate 10. That is, the first extension conductor includes the via conductors 33e and 33a and the land 35e. As will be described later, the first extension conductor connects the first external electrode 21 and the opposing coil conductor 32a within the laminate 10.

[0044] The via conductors 33f and the lands 35f form a second extension conductor within the laminate 10 and are exposed at the second end surface 12 of the laminate 10. That is, the second extension conductor includes the via conductors 33f and the lands 35f. As will be described later, the second extension conductor connects the second external electrode 22 and the opposing coil conductor 32d within the laminate 10.

[0045] When viewed from the stacking direction (length direction L), the coil conductors 32 preferably overlap each other. When viewed from the stacking direction, the coil may have a shape composed of straight lines (for example, a polygonal shape such as a rectangle) as shown in Fig. 2, a shape composed of curved lines (for example, a circular shape), or a shape composed of straight lines and curved lines.

[0046] FIG. 3 is a perspective side view schematically showing an example of the internal structure of a laminate constituting the laminated coil component shown in FIG.

[0047] 3, in the laminated coil component 1, a plurality of insulating layers 31 are stacked in the length direction L, and therefore the length direction L is the stacking direction. The stacking direction of the laminate 10 and the coil axis A of the coil 30 are parallel to the first main surface 13, the second main surface 14, the first side surface 15, or the second side surface 16, which are mounting surfaces.

[0048] As shown in FIG. 3, no boundary between adjacent insulating layers 31 is actually visible.

[0049] The first extension conductor 41 extends in the stacking direction within the laminate 10, and linearly connects the first external electrode 21 provided on the first end face 11 to the coil conductor 32a facing it. Similarly, the second extension conductor 42 extends in the stacking direction within the laminate 10, and linearly connects the second external electrode 22 provided on the second end face 12 to the coil conductor 32d facing it. Here, the first extension conductor 41 extends in the stacking direction, while the coil conductor 32a connected to the first extension conductor 41 extends in a direction perpendicular to the stacking direction. Therefore, it can be said that the transition portion (extension connection portion) between the first extension conductor 41 and the coil conductor 32a connected to the first extension conductor 41 is bent. Similarly, the second extension conductor 42 extends in the stacking direction, while the coil conductor 32d connected to the second extension conductor 42 extends in a direction perpendicular to the stacking direction. Therefore, it can be said that the transition portion (extension connection portion) between the second extension conductor 42 and the coil conductor 32d connected to the second extension conductor 42 is bent.

[0050] When viewed from the stacking direction (length direction L), it is preferable that the via conductors constituting the lead conductor overlap each other, but the via conductors constituting the lead conductor do not have to be aligned in a strict straight line.

[0051] Furthermore, Figures 2 and 3 illustrate an example in which the number of layers of the coil conductor 32 required to form three turns of the coil 30 is four, i.e., the repeating shape is a 3 / 4 turn shape, but the number of layers of the coil conductor 32 required to form one turn of the coil 30 is not particularly limited. For example, the number of laminations of the coil conductor 32 for forming one turn of the coil 30 may be two, that is, the repeating shape may be a 1 / 2 turn shape.

[0052] The number of layers of the coil conductors 32, that is, the total number of layers of the coil conductors 32 included in the laminate 10, is not particularly limited, but is preferably 30 or more and 120 or less.

[0053] Fig. 4 is a cross-sectional view schematically showing an example of a cross section taken along line A1-A1 of the laminated coil component shown in Fig. 1. Fig. 4 is also a cross-section obtained by cutting the laminated coil component shown in Fig. 1 so that the LW plane is exposed at a position overlapping the first lead conductor and the second lead conductor. Fig. 5 is a cross-sectional view schematically showing an example of a cross section taken along line A2-A2 of the laminated coil component shown in Fig. 1. Fig. 5 is also a cross-section obtained by cutting the laminated coil component shown in Fig. 1 so that the LT plane is exposed at a position where the first extension conductor and the second extension conductor overlap.

[0054] As shown in FIG. 4, of the coil conductors 32, the coil conductor directly connected to the first lead conductor 41 is the first coil conductor 132a. As shown in FIG. 5, of the coil conductors 32, the coil conductor that is directly connected to the second lead conductor 42 is the second coil conductor 132d. Therefore, the laminate 10 has one layer each of the first coil conductor 132a and the second coil conductor 132d. Of the coil conductors 32, those other than the first coil conductor 132a and the second coil conductor 132d are also referred to as third coil conductors.

[0055] 4 and 5, pores 50 are formed in the land 35e and via conductors 33e and 33a that constitute the first extension conductor 41, and in the land 35f and via conductor 33f that constitute the second extension conductor 42. Pores 50 are also formed in the first coil conductor 132a and the second coil conductor 132d. Similarly, pores 50 are also formed in the coil conductors 32 (third coil conductors) other than the first coil conductor 132a and the second coil conductor 132d, and in the via conductors 33a, 33b, 33c, and 33d that connect the third coil conductors.

[0056] The size of the pores may be the same in the first extraction conductor, the second extraction conductor, the first coil conductor and the second coil conductor and in the coil conductors other than the first coil conductor and the second coil conductor (third coil conductor), but in Figures 4 and 5, the size of the pores 50 formed in the first extraction conductor 41, the second extraction conductor 42, the first coil conductor 132a and the second coil conductor 132d is smaller than the size of the pores 50 formed in the coil conductors 32 other than the first coil conductor 132a and the second coil conductor 132d (third coil conductors) and the via conductors 33a, 33b, 33c and 33d connecting the third coil conductors to each other. 4 and 5, the pores 50 are not exposed to the outside of the conductor (at the boundary between the conductor and the insulating layer), but the pores 50 may be exposed to the outside of the conductor and in contact with the insulating layer 31.

[0057] In the laminate 10 shown in FIGS. 4 and 5, the pore area ratios of the first extension conductor 41, the second extension conductor 42, the first coil conductor 132a and the second coil conductor 132d are 1.00% or more and 11.00% or less, respectively.

[0058] When the pore area ratios of the first draw-out conductor, the second draw-out conductor, the first coil conductor and the second coil conductor are 1.00% or more and 11.00% or less, respectively, pores are less likely to concentrate at the bend (draw-out connection) where the coil conductor and the draw-out conductor change over, thereby reducing the risk of breakage. If the pore area ratio of the first extraction conductor, the second extraction conductor, the first coil conductor and the second coil conductor is less than 1.00%, the thermal shrinkage of the coil conductors will be too large, resulting in increased residual stress between the insulating layer and the conductors, making cracks more likely to occur.

[0059] The pore area ratio is the ratio of the area occupied by pores (voids, air holes) per unit area of ​​the internal electrode formed by baking the conductive paste. The pore area ratio can be determined by obtaining an image of the entire cross section of the multilayer coil component in a plane perpendicular to the lamination direction of the insulating layers and passing through the center of the lead conductor using an electron microscope, and analyzing the obtained image using commercially available image analysis software (for example, A-Zo-kun (registered trademark) manufactured by Asahi Kasei Engineering Corporation). Specifically, for example, the pore area ratio can be calculated by using image analysis software to distinguish between the pore portions and the conductor portions in a predetermined region of the internal electrode (for example, the region corresponding to the first extension conductor) by binarization or the like, and determining the ratio of the area of ​​the pore portions to the total area of ​​the pore portions and the conductor portions. If the first extension conductor 41 and the second extension conductor are not on the same cross section, it is sufficient to obtain two types of images: one of an image of the entire cross section of the laminated coil component taken in a plane perpendicular to the stacking direction of the insulating layers and passing through the center of the first extension conductor 41, and the other of an image of the entire cross section of the laminated coil component taken in a plane perpendicular to the stacking direction of the insulating layers and passing through the center of the second extension conductor 43.

[0060] FIG. 6 is a cross-sectional view schematically showing an example of a laminated coil component that does not satisfy the features of the present invention. 6, the pore area ratio of each of the first extension conductor 41, the second extension conductor 42, and the first coil conductor 132a exceeds 11.00%. Although not shown, the pore area ratio of the second coil conductor also exceeds 11.00%. Therefore, as shown in FIG. 6, pores 50 are concentrated at the connection (bent portion) between the first extraction conductor 41 and the first coil conductor 132a and the connection (bent portion) between the second extraction conductor 42 and the second coil conductor 132d, increasing the risk of breakage.

[0061] The pore area ratios of the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor may be 1.00% or more and 4.00% or less, respectively. When the pore area ratios of the first lead conductor, second lead conductor, first coil conductor, and second coil conductor are 1.00% or more and 4.00% or less, respectively, pores are even less likely to concentrate at the bend (lead connection) where the coil conductor and lead conductor switch, which not only reduces the risk of disconnection but also prevents the current path from becoming extremely narrowed (current concentration) due to concentrated pores, even if it does not result in disconnection, thereby ensuring reliable conduction.

[0062] The thickness of the first coil conductor may be greater than the maximum pore diameter in the first coil conductor. If the thickness of the first coil conductor is larger than the diameter of the largest pore in the first coil conductor, the largest pore alone will not cause the first coil conductor to break, thereby further reducing the risk of breakage due to pores.

[0063] The thickness of the second coil conductor may be greater than the maximum pore diameter in the second coil conductor. If the thickness of the second coil conductor is larger than the diameter of the largest pore in the second coil conductor, the second coil conductor will not be broken by the largest pore alone, and the risk of breakage due to pores can be further reduced.

[0064] The pore diameter is the area of ​​each pore converted into the diameter of a circle equivalent to that area. The maximum pore diameter refers to the largest pore diameter calculated from all the pores present in the region. For example, the maximum pore diameter in the first coil conductor is the area of ​​the largest pore (maximum pore) present in the first coil conductor in a specific cross section, converted into the diameter of a circle with that area.

[0065] The thickness of the first coil conductor is found by dividing the total area of ​​the first coil conductor (the sum of the area of ​​the conductor portion and the area of ​​the pore portion) in the cross-sectional view of the laminated coil component used to measure the pore diameter by the dimension of the first coil conductor in the direction perpendicular to the lamination direction of the insulating layers. The thickness of the second coil conductor can be determined in a similar manner.

[0066] The maximum pore diameter in the first coil conductor is preferably 70% or less, more preferably 50% or less, of the thickness of the first coil conductor, and is preferably 10% or more, more preferably 30% or more, of the thickness of the first coil conductor. The maximum pore diameter in the second coil conductor is preferably 70% or less, more preferably 50% or less, of the thickness of the second coil conductor, and is preferably 10% or more, more preferably 30% or more, of the thickness of the second coil conductor.

[0067] The pore area ratio of at least one layer of a coil conductor other than the first coil conductor and the second coil conductor (third coil conductor) is preferably larger than the pore area ratios of the first coil conductor and the second coil conductor.

[0068] It is preferable that the pore area ratio of at least one layer of the third coil conductor, which is a coil conductor other than the first coil conductor and the second coil conductor, is more than 11.00% and not more than 20.00%. A coil conductor with a pore area ratio of more than 11.00% and not more than 20.00% can be said to have a large shrinkage rate during sintering. If at least one layer of the third coil conductor has such a coil conductor, the shrinkage rate of the insulating layer and the shrinkage rate of the coil conductor can be made closer when the laminate is sintered. As a result, it is possible to suppress deterioration of the electrical properties of the coil due to differences in the shrinkage rates of the insulating layer and the coil conductor.

[0069] Furthermore, since the coil conductor other than the first coil conductor and the second coil conductor (the third coil conductor) is connected to the first or second lead conductor via the winding portion of the first or second coil conductor, it is farther from the bend than the first or second coil conductor. Therefore, it is considered very unlikely that pores formed in the third coil conductor will migrate to the bend during firing. Therefore, even if the pore area ratio of the third coil conductor exceeds 11.00%, it does not increase the risk of breakage at the bend (lead connection portion). On the other hand, if the third coil conductor, which is a coil conductor other than the first coil conductor and the second coil conductor, does not contain a single layer of coil conductor with a pore area ratio of 20.00% or less, i.e., if the pore area ratio of all third coil conductors exceeds 20.00%, the Rdc (internal resistance) of the coil, which is the internal electrode, will become high. In other words, it is preferable that all coil conductors other than the first coil conductor and the second coil conductor, that is, all third coil conductors, have a pore area ratio of 20.00% or less.

[0070] The pore area ratio of two or more layers of the third coil conductor may be more than 11.00% and not more than 20.00%, or some of the third coil conductors may have a pore area ratio of 11.00% or less. However, the number of layers of the third coil conductor having a pore area ratio of 11.00% or less is preferably smaller than the number of layers of the third coil conductor having a pore area ratio of more than 11.00% but not more than 20.00%.

[0071] When the number of layers of all the third coil conductors is taken as 100%, the pore area ratio of the third coil conductors with 50% or more layers is preferably more than 11.00% and 20.00% or less.

[0072] When a third coil conductor other than the first coil conductor and the second coil conductor includes both a coil conductor with a pore area ratio of 11.00% or less and a coil conductor with a pore area ratio of more than 11.00% and less than 20.00%, the arrangement (position) of the coil conductor with a pore area ratio of 11.00% or less and the coil conductor with a pore area ratio of more than 11.00% and less than 20.00% is not particularly limited, but it is preferable that the coil conductor with a pore area ratio of 11.00% or less is located closer to the first coil conductor or the second coil conductor than the coil conductor with a pore area ratio of more than 11.00% and less than 20.00%, and it is more preferable that it is located adjacent to the first coil conductor or the second coil conductor in the stacking direction.

[0073] It is preferable that the pore area ratio of all coil conductors other than the first coil conductor and the second coil conductor, that is, all third coil conductors, is greater than 11.00% and not more than 20.00%. When the pore area ratio of all the third coil conductors is greater than 11.00% and less than or equal to 20.00%, all the coil conductors except the first and second coil conductors are composed of coil conductors with a large shrinkage rate during sintering, so that when the laminate is sintered, the shrinkage rates of the insulating layers and the coil conductors can be made as close as possible to each other, thereby further suppressing deterioration in the electrical properties of the coil due to differences in the shrinkage rates of the insulating layers and the coil conductors.

[0074] The maximum pore diameters of the first lead conductor, second lead conductor, first coil conductor and second coil conductor are preferably smaller than the maximum pore diameter of a coil conductor other than the first coil conductor and second coil conductor (third coil conductor). By satisfying the above configuration, the risk of disconnection due to pores in the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor can be further reduced.

[0075] Note that the maximum pore diameter in the coil conductors other than the first coil conductor and the second coil conductor means the diameter of the largest pore among all pores present in the coil conductors other than the first coil conductor and the second coil conductor (the third coil conductor).

[0076] When the pore area ratio of at least one layer of a coil conductor (third coil conductor) other than the first coil conductor and the second coil conductor is greater than 11.00% and less than 20.00%, it is preferable that the largest pores in the coil conductors other than the first coil conductor and the second coil conductor are present in a coil conductor having a pore area ratio of greater than 11.00% and less than 20.00%. Furthermore, it is preferable that the maximum pore diameter of each coil conductor having a pore area ratio of more than 11.00% and not more than 20.00% is larger than the maximum pore diameters of the first extension conductor, the second extension conductor, the first coil conductor and the second coil conductor, respectively.

[0077] The via conductors that constitute the first extraction conductor are also called first via conductors, and the via conductors that constitute the second extraction conductor are also called second via conductors. Of the via conductors that constitute the internal electrode, the via conductors other than the first and second via conductors are also called third via conductors. The third via conductor may have a pore.

[0078] The pore area ratio of the third via conductor is not particularly limited, but is preferably the same as that of the third coil conductor, i.e., the pore area ratio of the third via conductor is preferably more than 11.00% and not more than 20.00%. The pore diameter distribution of the third via conductor is not particularly limited, but is preferably similar to that of the third coil conductor. For example, the maximum pore diameter of the third via conductor may be the same as that of the third coil conductor. It is preferable that the maximum pore diameter of the third coil conductor and the third via conductor, whose pore area ratio is greater than 11.00% and not more than 20.00%, is larger than the respective maximum pore diameters of the first extraction conductor, the second extraction conductor, the first coil conductor and the second coil conductor.

[0079] The insulating layer preferably contains ferrite and has a pore area ratio of 0.10% or more and 5.00% or less. When the insulating layer contains ferrite and has a pore area ratio of 0.10% to 5.00%, the resistance of the insulating layer is sufficiently high, and short circuits are unlikely to occur between coil conductors facing each other across the insulating layer, even when a large current flows. When the pore area ratio of the insulating layer exceeds 5.00%, short circuits may be more likely to occur between coil conductors facing each other across the insulating layer. However, insulating layers containing ferrite and with a pore area ratio of 0.10% to 5.00% shrink significantly during sintering. In such cases, the shrinkage of the insulating layer during sintering can apply stress to the coil conductor, resulting in a decrease in electrical properties (magnetic permeability). However, if the pore area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is greater than 11.00% and less than 20.00%, the shrinkage ratio of the insulating layer can be made closer to the shrinkage ratio of the conductor paste that becomes the coil conductor.Therefore, even if the insulating layer contains ferrite and the pore area ratio is greater than 0.10% and less than 5.00%, the stress applied to the coil conductor can be reduced, and the deterioration of the electrical properties (magnetic permeability) can be suppressed.

[0080] In this specification, "a coil conductor is directly connected to a lead conductor" means that the coil conductor is directly connected to the lead conductor without passing through the winding portion of another coil conductor. Therefore, when a first lead conductor is directly connected to multiple coil conductors without passing through the winding portion of the coil conductor, multiple layers of first coil conductors exist. Similarly, when a second lead conductor is directly connected to multiple coil conductors without passing through the winding portion of the coil conductor, multiple layers of second coil conductors exist.

[0081] An example of a laminated coil component having two layers of first coil conductors and second coil conductors will be described as a laminated coil component according to a second embodiment of the present invention.

[0082] FIG. 7 is an exploded perspective view schematically showing an example of a laminate constituting an example of a laminate coil component according to a second embodiment of the present invention. As shown in FIG. 7, the laminate 60 is formed by stacking a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in a stacking direction (here, length direction L) from the first end face 11 side of the laminate 10 toward the second end face 12 side.

[0083] However, unlike the first insulating layer 31a counting from the first end face 11 side, the second and third insulating layers 31a have via conductors 33a provided directly below both of the lands 35a provided at both ends of the circumferential portion 34a. Similar to the insulating layer 31a, the fifth insulating layer 31b counting from the first end face 11 side has via conductors 33b provided directly below both of the lands 35b provided at both ends of the circumferential portion 34b, unlike the fourth insulating layer 31b counting from the first end face 11 side. Similar to insulating layer 31a and insulating layer 31b, insulating layer 31d, which is the eighth layer counting from the first end face 11 side, has via conductors 33d provided directly below both of lands 35d provided at both ends of the circumferential portion 34d, unlike insulating layer 31d, which is the seventh layer counting from the first end face 11 side. As a result, the coil conductors having winding portions with the same shape (the coil conductors 32a, the coil conductors 32b, and the coil conductors 32d) are connected in parallel to each other.

[0084] FIG. 8 is a side view schematically showing, in a see-through manner, the state of pores in the internal electrodes of the laminated coil component including the laminate shown in FIG.

[0085] As shown in FIG. 8, the laminated coil component 3 includes a laminate 60, a first external electrode 21 covering a first end face 11 of the laminate 60, and a second external electrode 22 covering a second end face 12 thereof. Inside the laminate 60, a first lead conductor 41, a second lead conductor 42, and a coil 130, which serve as internal electrodes, are arranged. In the laminate 60, the coil conductors 32a in the first, second, and third layers counting from the first end face 11 are connected in the stacking direction by via conductors 33a2 and 33a3. Therefore, the coil conductors 32a (132a1, 132a2, 132a3) in the first, second, and third layers counting from the first end face 11 can all be considered first coil conductors directly connected to the first extension conductor 41. The first coil conductors 132a1, 132a2, and 132a3 are collectively referred to as first coil conductors 132a. Similarly, the coil conductors 32d in the seventh and eighth layers counting from the first end face 11 are connected in the stacking direction by via conductors 33f. Therefore, the coil conductors 132d1 and 132d2 in the seventh and eighth layers counting from the first end face 11 can be said to be second coil conductors directly connected to the second extension conductor 42. The second coil conductors 132d1 and 132d2 are also collectively referred to as second coil conductors 132d. Note that in FIG. 8, the via conductor 33f does not appear to overlap with the via conductor 33d between the coil conductors 132d1 and 132d2.

[0086] Coil conductors other than the first coil conductor 132a and the second coil conductor 132d are connected to the first draw-out conductor 41 or the second draw-out conductor 42 via the winding portion 34a of the first coil conductor 132a or the winding portion 34d of the second coil conductor 132d, and therefore do not fall under the category of coil conductors directly connected to the first draw-out conductor 41 or the second draw-out conductor 42.

[0087] The first coil conductors 132a1, 132a2, and 132a3, each having the same shaped winding portion 34a, are connected in parallel by the via conductor 33a. Similarly, the two-layer coil conductors 32b, each having the same shaped winding portion 34b, are connected in parallel by the via conductor 33b, and the second coil conductors 132d1 and 132d2, each having the same shaped winding portion 34d, are connected in parallel by the via conductor 33d. Such a coil is called a parallel multi-turn coil (inductor).

[0088] 8 , in a case where three layers of first coil conductors 132a1, 132a2, and 132a3 are directly connected to the first extension conductor 41, and a via conductor 33a2 connects the first coil conductor 132a1 to the first coil conductor 132a2, and a via conductor 33a3 connects the first coil conductor 132a2 to the first coil conductor 132a3, a portion 132a11 of the first coil conductor 132a1 that is sandwiched between the via conductor 33a1 and the via conductor 33a2, and a portion 132a21 of the first coil conductor 132a2 that is sandwiched between the via conductor 33a2 and the via conductor 33a3 are treated as the first extension conductor 41.

[0089] Similarly, when there are two layers of second coil conductors 132d1 and 132d2 directly connected to the second draw-out conductor 42, and a via conductor 33d connects between the second coil conductor 132d1 and the second coil conductor 232d2, the portion 132d21 of the second coil conductor 132d2 sandwiched between the via conductor 33f and the via conductor 33d that constitute the second draw-out conductor 42 is treated as the second draw-out conductor 42.

[0090] In the laminate 60 shown in FIG. 8, the pore area ratios of the first extension conductor 41, the second extension conductor 42, the first coil conductors 132a1, 132a2 and 132a3, and the second coil conductors 132d1 and 132d2 are all 1.00% or more and 11.00% or less.

[0091] It is believed that the outward attraction of bubbles generated inside the conductor paste during firing is strongest at the exposed portions of the lead conductors, where the internal electrodes of the laminate are exposed, and weakens toward the center. Therefore, when there are multiple first coil conductors, the risk of disconnection can be reduced by setting the pore area ratio of all first coil conductors to 1.00% or more and 11.00% or less. Similarly, when there are multiple second coil conductors, the risk of disconnection can be reduced by setting the pore area ratio of all second coil conductors to 1.00% or more and 11.00% or less.

[0092] The present invention is not limited to a configuration in which the lamination direction of the insulating layers and the extension direction of the lead conductors are parallel to the mounting surface (horizontal wound laminated coil component), but can also be applied to a configuration in which the lamination direction of the insulating layers and the extension direction of the lead conductors are perpendicular to the mounting surface (vertical wound laminated coil component). An example of the vertically wound laminated coil component will be described as a laminated coil component according to a third embodiment of the present invention.

[0093] FIG. 9 is a perspective view schematically illustrating an example of a laminated coil component according to a third embodiment of the present invention. As shown in FIG. 9, the laminated coil component 5 includes a laminate 70, a first external electrode 21, and a second external electrode 22. The laminate 70 has a first end face 11 and a second end face 12 facing in the longitudinal direction L, a first main face 13 and a second main face 14 facing in the height direction T perpendicular to the longitudinal direction L, and a first side face 15 and a second side face 16 facing in the width direction W perpendicular to the longitudinal direction L and the height direction T.

[0094] The first external electrode 21 is an oblique electrode that covers a portion of the first end face 11, a portion of the first main surface 13 that extends from the first end face 11 and serves as the mounting surface, and a portion of the first side face 15 and the second side face 16 that extend from the first end face 11 and the first main surface 13.

[0095] The second external electrode 22 is an oblique electrode that covers a portion of the second end face 12, a portion of the first main surface 13 that extends from the second end face 12 and serves as the mounting surface, and a portion of the first side face 15 and the second side face 16 that extend from the second end face 12 and the first main surface 13. The shapes of the first external electrodes and the second external electrodes are not limited to the oblique electrodes described above, and may be the same as the shapes of the laminated coil component 1 shown in FIGS. 1 to 5 and the laminated coil component 3 shown in FIGS.

[0096] FIG. 10 is an exploded perspective view schematically showing an example of a laminate constituting the laminated coil component shown in FIG. 10, the laminate 70 is configured by stacking a plurality of insulating layers 131a, 131b, 131c, 131d, 131g, 131h, and 131i in a stacking direction (here, height direction T) from the first main surface 13 toward the second main surface 14 of the laminate 10. Hereinafter, the insulating layers 131a, 131b, 131c, 131d, 131g, 131h, and 131i will also be collectively referred to as insulating layers 131.

[0097] The insulating layers 131a, 131b, 131c, and 131d are provided with coil conductors 32a, 32b, 32c, and 32d, via conductors 33a, 33b, 33c, and 33d, a land 35f, and a via conductor 33f, respectively. The coil conductors 32a, 32b, 32c, and 32d each include an annular winding portion 34a, 34b, 34c, and 34d that is partially missing, leaving a gap, and lands 35a, 35b, 35c, and 35d. Lands 35a, 35b, 35c, and 35d are provided at both ends of the winding portion 34a, 34b, 34c, and 34d, respectively. The land 35f and the via conductor 33f are provided apart from the coil conductors 32a, 32b, 32c, and 32d.

[0098] The insulating layer 131h is provided with a coil conductor 132b and a via conductor 33b. The coil conductor 132b includes a winding portion 134b that partially overlaps with the winding portion 34b of the coil conductor 32b, and lands 35b provided on both ends of the winding portion 134b.

[0099] The insulating layer 131g is provided with lands 35e and 35f and via conductors 33e and 33f. The insulating layer 131g may be one layer or two or more layers.

[0100] The insulating layer 131i is not provided with a coil conductor, a land, or a via conductor. The insulating layer 131i may be one layer or two or more layers.

[0101] FIG. 11 is a cross-sectional view schematically illustrating an example of a cross section of the laminated coil component shown in FIG. 9 taken along line A3-A3. As shown in FIG. 11, inside the laminate 70, a first extension conductor 41, a second extension conductor 42, and a coil 230, which serve as internal electrodes, are arranged. The coil 230 is formed by electrically connecting the coil conductors 132a, 32b, 32c, 32d, 32a, and 132b in the stacking direction by the via conductors 33b, 33c, and 33d.

[0102] The via conductor 33a, the via conductor 33e, and the land 35e formed in the insulating layer 131a adjacent to the insulating layer 131g become the first extraction conductor 41 within the laminate 70 and are exposed on the first end face 11 side of the first main surface 13 of the laminate 70. Of the two lands 35b formed on the insulating layer 131h, the land 35b located at a position that does not overlap with the circumferential shape of the coil, the via conductor 33b located directly below the land 35b, the via conductor 33f, and the land 35f form a second extraction conductor 42 within the laminate 70 and are exposed on the second end surface 12 side of the first main surface 13 of the laminate 70.

[0103] The direction in which the first extension conductor 41 and the second extension conductor 42 extend is parallel to the lamination direction of the insulating layers and is perpendicular to the first main surface 13 which is the mounting surface. The first extension conductor 41 and the second extension conductor 42 are exposed on the same surface (first main surface 13) of the laminate 70.

[0104] Of the coil conductors, the coil conductor 32a directly connected to the first lead conductor 41 is the first coil conductor 132a. Of the coil conductors, the coil conductor 132b directly connected to the second lead conductor 42 is the second coil conductor. Therefore, the laminate 70 has one layer each of the first coil conductor 132a and the second coil conductor 132b. Of the coil conductors, those other than the first coil conductor 132a and the second coil conductor 132b are also referred to as third coil conductors.

[0105] 11, pores 50 are formed in the via conductors 33a and 33e and the land 35e that constitute the first extension conductor 41, and in the via conductors 33b and 33f and the lands 35b and 35f that constitute the second extension conductor 42. Pores 50 are also formed in the coil conductors 32a, 32b, 32c, and 32d that are coil conductors (third coil conductors) other than the first coil conductor 132a and the second coil conductor 132b, and in the via conductors 33a, 33b, 33c, and 33d that connect the third coil conductors to each other.

[0106] In the laminate 70 shown in FIG. 11, the pore area ratios of the first extension conductor 41, the second extension conductor 42, the first coil conductor 132a and the second coil conductor 132b are 1.00% or more and 11.00% or less, respectively.

[0107] The fact that pores generated in and near the lead conductors are drawn outward when the conductor paste is fired has nothing to do with whether the lamination direction of the coil conductors is parallel or perpendicular to the mounting surface. Therefore, even in a vertically wound multilayer coil component, if the pore area ratios of the first lead conductor 41, the second lead conductor 42, the first coil conductor 132a, and the second coil conductor 132b are 1.00% or more and 11.00% or less, respectively, the risk of disconnection at the lead connection can be reduced, just like in the horizontally wound multilayer coil component 1 shown in Figures 1, 2, 3, 4, and 5.

[0108] [Manufacturing method for multilayer coil components] A method for manufacturing a laminated coil component according to a first embodiment of the present invention includes: a laminate formed by laminating a plurality of insulating layers and having internal electrodes; and first and second external electrodes electrically connected to the internal electrodes, wherein the internal electrodes include a coil formed by electrically connecting a plurality of coil conductors laminated together with the insulating layers, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, wherein the first lead conductor and the second lead conductor extend in a lamination direction of the insulating layers, the method comprising the steps of: preparing ceramic green sheets containing a ceramic material; and depositing a conductor paste on a plurality of the ceramic green sheets. the step of stacking a plurality of the ceramic green sheets on which the conductor paste layers have been formed to produce an unfired laminate having an unfired coil built in; and the step of firing the unfired laminate to produce a laminate, wherein, of the coil conductors, the coil conductor directly connected to the first draw conductor is defined as the first coil conductor and the coil conductor directly connected to the second draw conductor is defined as the second coil conductor, the PVC of the conductor paste for the first coil conductor, the second coil conductor, the first draw conductor and the second draw conductor is 45.00% or more and 55.00% or less.

[0109] An example of the method for producing the laminated coil component of the present invention will now be described.

[0110] <Magnetic material manufacturing process> First, Fe2O3, ZnO, CuO, and NiO are weighed out to give a predetermined ratio.

[0111] Next, these weighed materials and pure water are placed in a ball mill together with PSZ (partially stabilized zirconia) media, mixed, and then pulverized. The mixing and pulverization time is, for example, 4 hours or more and 8 hours or less.

[0112] The resulting pulverized material is then dried and then calcined at a calcination temperature of, for example, 700° C. to 800° C. for, for example, 2 hours to 5 hours.

[0113] In this manner, a powdered magnetic material, more specifically, a powdered magnetic ferrite material is produced.

[0114] The ferrite material is preferably a Ni-Cu-Zn based ferrite material.

[0115] When the total amount of the Ni-Cu-Zn ferrite material is taken as 100 mol%, it is preferable that the material contains Fe in an amount of 40 mol% to 49.5 mol% inclusive, calculated as Fe2O3, Zn in an amount of 2 mol% to 35 mol% inclusive, calculated as ZnO, Cu in an amount of 6 mol% to 13 mol% inclusive, and Ni in an amount of 10 mol% to 45 mol% inclusive, calculated as NiO.

[0116] The Ni-Cu-Zn ferrite material may further contain additives such as Co, Bi, Sn, and Mn.

[0117] The Ni—Cu—Zn ferrite material may further contain inevitable impurities.

[0118] <Green sheet manufacturing process> First, a magnetic material, an organic binder such as polyvinyl butyral resin, an organic solvent such as ethanol or toluene, and a plasticizer are mixed in a ball mill together with PSZ media, and then pulverized to produce a slurry.

[0119] Next, the slurry is formed into a sheet of a predetermined thickness by a doctor blade method or the like, and then punched into a predetermined shape to produce a green sheet. The thickness of the green sheet is, for example, 20 μm or more and 30 μm or less. The shape of the green sheet is, for example, rectangular.

[0120] As the material for the green sheets, instead of a magnetic material, a non-magnetic material such as borosilicate glass material may be used, or a mixed material of a magnetic material and a non-magnetic material may be used.

[0121] <Conductor pattern formation process> First, a via hole is formed by irradiating a predetermined portion of the green sheet with a laser.

[0122] Next, a conductor paste containing a conductive material, a resin component, and a solvent is applied to the surface of the green sheet by screen printing or the like, filling the via holes. This forms via conductor patterns in the via holes of the green sheet, while forming coil conductor conductor patterns and / or land conductor patterns connected to the via conductor conductor patterns on the surface. In this manner, a coil sheet is produced in which the coil conductor conductor patterns and / or land conductor patterns and the via conductor conductor patterns are formed on the green sheet. The coil sheet is formed with a coil conductor conductor pattern corresponding to the coil conductor 32 shown in FIG. 2 and a via conductor pattern corresponding to the via conductor 33 shown in FIG. 2 (excluding via conductors 33e and 33f). Separately from the coil sheet, a via sheet is produced in which a via conductor conductor pattern corresponding to the via conductors 33e and 33f shown in FIG. 2 is formed.

[0123] In the method for manufacturing the laminated coil component according to the first embodiment of the present invention, the PVC of the conductor paste for the first extraction conductor (conductor paste for forming the land conductor pattern and via conductor conductor pattern that will become the first extraction conductor), the conductor paste for the second extraction conductor (conductor paste for forming the land conductor pattern and via conductor conductor pattern that will become the second extraction conductor), the conductor paste for the first coil conductor (conductor paste for forming the coil conductor conductor pattern that will become the first coil conductor), and the conductor paste for the second coil conductor (conductor paste for forming the coil conductor conductor pattern that will become the second coil conductor) is set to 45.00% or more and 55.00% or less, respectively.

[0124] By setting the PVC of the conductor paste for the first coil conductor, the second coil conductor, the first extension conductor and the second extension conductor to 45.00% or more and 55.00% or less, the pore area ratio of the first extension conductor, the second extension conductor, the first coil conductor and the second coil conductor can be set to 1.00% or more and 11.00% or less, respectively, and the laminated coil component of the present invention can be obtained.

[0125] It should be noted that PVC is the concentration of the volume of the conductive material (typically metal powder) relative to the total volume of the conductive material and resin component in the conductor paste (Pigment Volume Concentration). Since PVC indicates the volume fraction of non-resin components in a conductor paste, a conductor formed using a conductor paste with a relatively high PVC will have a smaller pore area ratio than a conductor formed using a conductor paste with a relatively low PVC.

[0126] Examples of conductive materials include metal powders of Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals, and among these, Ag powder is preferred.

[0127] The resin component may be ethyl cellulose or the like.

[0128] In this specification, the conductor paste for the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor is also referred to as a low-pore conductor paste. In the method for producing the laminated coil component according to the first embodiment of the present invention, the low pore conductor paste is a conductor paste having a PVC content of 45.00% or more and 55.00% or less.

[0129] The above-mentioned low pore conductor paste may be used as the conductor paste for coil conductors other than the first coil conductor and the second coil conductor, but it is preferable to use a conductor paste with a PVC content of 30.00% or more and 40.00% or less for at least one layer.

[0130] That is, the PVC of the conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is preferably 30.00% or more and 40.00% or less. When the PVC of the conductor paste for at least one layer of the coil conductor other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less, the pore area ratio of at least one layer of the coil conductor other than the first coil conductor and the second coil conductor can be more than 11.00% and 20.00% or less.

[0131] When the pore area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is more than 11.00% and not more than 20.00%, the shrinkage rate of the insulating layer and the shrinkage rate of the coil conductor can be made close to each other when sintering the laminate, thereby suppressing deterioration of the electrical properties of the coil due to the difference between the shrinkage rates of the insulating layer and the coil conductor.

[0132] When the number of layers of all coil conductors other than the first coil conductor and the second coil conductor is taken as 100%, it is more preferable that the PVC of the conductor paste for 50% or more of the coil conductors is 30.00% or more and 40.00% or less. When the PVC of the conductor paste for 50% or more of the layers of all coil conductors other than the first and second coil conductors is 30.00% or more and 40.00% or less, the pore area ratio of 50% or more of the coil conductors other than the first and second coil conductors can be made greater than 11.00% and less than 20.00%, which allows the shrinkage rate of the insulating layer and the shrinkage rate of the coil conductor to be closer when sintering the laminate. As a result, deterioration of the electrical properties of the coil due to the difference between the shrinkage rates of the insulating layer and the coil conductor can be more effectively suppressed.

[0133] It is more preferable that the PVC of the conductor paste for all coil conductors other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less. When the PVC of the conductor paste for all coil conductors other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less, the pore area ratio of all coil conductors other than the first coil conductor and the second coil conductor can be more than 11.00% and 20.00% or less.

[0134] When the pore area ratio of all coil conductors other than the first and second coil conductors is greater than 11.00% and less than or equal to 20.00%, all coil conductors other than the first and second coil conductors have a large shrinkage rate during sintering, which allows the shrinkage rates of the insulating layers and the coil conductors to be as close as possible when sintering the laminate. As a result, deterioration of the electrical properties of the coil due to differences in the shrinkage rates of the insulating layers and the coil conductors can be further suppressed.

[0135] In this specification, a conductor paste for forming a coil conductor layer having a pore area ratio of more than 11.00% and not more than 20.00% is also referred to as a conductor paste for high pores. In the method for producing the laminated coil component according to the first embodiment of the present invention, the high-pore conductor paste is a conductor paste containing PVC in a range of 30.00% to 40.00%.

[0136] That is, in the manufacturing method of the laminated coil component according to the first embodiment of the present invention, it is preferable to use a low pore conductor paste to form the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor, and then use a high pore conductor paste to form at least one layer of a coil conductor (third coil conductor) other than the first coil conductor and the second coil conductor; it is more preferable to use a high pore conductor paste to form 50% or more of the layers of the third coil conductors when the number of layers of all the third coil conductors is 100%, and it is even more preferable to use a high pore conductor paste to form all of the third coil conductors.

[0137] The above-mentioned high pore conductor paste may be used as a conductor paste for forming conductor patterns for via conductors other than the conductor pattern for via conductor that will become the first extraction conductor and the conductor pattern for via conductor that will become the second extraction conductor. In this case, the pore area ratio of the via conductor (third via conductor) other than the first via conductor and the second via conductor can be set to more than 11.00% and 20.00% or less.

[0138] The maximum pore diameter in a conductor formed using a low pore conductor paste is likely to be smaller than the maximum pore diameter in a conductor formed using a high pore conductor paste. Therefore, by using a conductor paste (low pore conductor paste) with a PVC content of 45.00% or more and 55.00% or less as the conductor paste for the first extension conductor, second extension conductor, first coil conductor, and second coil conductor, and using a conductor paste (high pore conductor paste) with a PVC content of 30.00% or more and 40.00% or less as the conductor paste for at least one layer of a coil conductor other than the first coil conductor and second coil conductor, the maximum pore diameter in each of the first extension conductor, second extension conductor, first coil conductor, and second coil conductor can be made smaller than the maximum pore diameter in the coil conductor other than the first coil conductor and second coil conductor (third coil conductor).

[0139] <Laminated block manufacturing process> The coil sheets and via sheets are stacked in the stacking direction (length direction L) in the order shown in FIG. 2, and then thermocompression bonded to form a laminated block.

[0140] <Laminate and coil manufacturing process> First, the laminate block is cut into a predetermined size using a dicer or the like to produce individual chips.

[0141] Next, the individual chips are fired at a firing temperature of, for example, 900° C. to 920° C. for, for example, 2 hours to 4 hours.

[0142] When the individual chips are fired, the green sheets of the coil sheet and via sheet become insulating layers.

[0143] Furthermore, when the singulated chips are fired, the conductor patterns for the coil conductors, the conductor patterns for the land conductors, and the conductor patterns for the via conductors become coil conductors, lands, and via conductors, respectively. As a result, a coil is produced in which multiple coil conductors stacked together with insulating layers are electrically connected through via conductors, and first and second lead conductors are produced that lead out the coil to the end faces of the laminate. At this time, pores are generated in the coil conductor, the land, and the via conductor at an area ratio that corresponds to the composition of the original conductor pattern (conductor paste).

[0144] In this way, a plurality of insulating layers are stacked in the stacking direction, and a laminate body with a built-in coil is produced.

[0145] The corners and ridges of the laminate may be rounded by, for example, barrel polishing.

[0146] <External electrode formation process> First, a conductive paste such as a paste containing Ag and glass frit is applied to the first end face and second end face from which the coil is drawn out of the outer surface of the laminate, thereby forming a conductive paste layer.

[0147] Next, the conductive paste layer is baked to form the base electrodes of the external electrodes. The baking temperature is, for example, 800° C. or higher and 820° C. or lower. The thickness of the base electrodes is, for example, 5 μm.

[0148] Then, a Ni-plated electrode and a Sn-plated electrode are formed in this order on the surface of the base electrode by electrolytic plating, etc. This forms an external electrode having the base electrode, Ni-plated electrode, and Sn-plated electrode in this order.

[0149] In this manner, the laminated coil component is manufactured.

[0150] A method for manufacturing a laminated coil component according to a second embodiment of the present invention includes a laminate formed by stacking a plurality of insulating layers and having internal electrodes, and first and second external electrodes electrically connected to the internal electrodes, wherein the internal electrodes include a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layers, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, wherein the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, the method comprising the steps of: preparing ceramic green sheets containing a ceramic material; and printing a conductive paste on a plurality of the ceramic green sheets to print the coil conductors, the first lead conductor and / or the second lead conductor. The method includes a printing step of forming a conductor paste layer that will become an output conductor, a step of stacking a plurality of the ceramic green sheets on which the conductor paste layer is formed to produce an unfired laminate having an unfired coil embedded therein, and a step of firing the unfired laminate to produce a laminate, wherein, when, among the coil conductors, the coil conductor that is directly connected to the first output conductor is defined as the first coil conductor and the coil conductor that is directly connected to the second output conductor is defined as the second coil conductor, the conductor paste for the first coil conductor, the second coil conductor, the first output conductor and the second output conductor contains metal powder produced by a method other than water atomization, and the conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor contains metal powder produced by water atomization.

[0151] Water atomization is a method of forming metal powder by injecting or colliding water onto molten metal, and since the molten metal comes into contact with water, oxygen is easily trapped inside the metal powder. Therefore, when a conductor paste containing metal powder produced by water atomization is fired, more pores are formed in the fired conductor than when a conductor paste containing metal powder produced by a method other than water atomization is fired. Note that "methods other than water atomization" include both methods other than atomization and atomization methods other than water atomization.

[0152] For the above reasons, the conductor paste for the first coil conductor, the second coil conductor, the first draw conductor and the second draw conductor contains metal powder produced by a method other than water atomization, and the conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor contains metal powder produced by water atomization, thereby making it possible to obtain a laminated coil component in which the pore area ratios of the first draw conductor, the second draw conductor, the first coil conductor and the second coil conductor are 1.00% or more and 11.00% or less, respectively, and in which the pore area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is more than 11.00% and 20.00% or less.

[0153] The manufacturing method for a laminated coil component according to the second embodiment of the present invention can be said to be a method in which the low pore conductor paste in the manufacturing method for a laminated coil component according to the first embodiment of the present invention is changed from "a conductor paste having a PVC content of 45.00% or more and 55.00% or less" to "a conductor paste containing metal powder manufactured by a method other than water atomization," and the high pore conductor paste is specified to "a conductor paste containing metal powder manufactured by water atomization." Therefore, in the manufacturing method of the laminated coil component according to the second embodiment of the present invention, the high pore conductor paste is a conductor paste containing metal powder manufactured by the water atomization method, and the low pore conductor paste is a conductor paste containing metal powder manufactured by a method other than the water atomization method.

[0154] Metal powders produced by water atomization include metal powders made of Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals, and among these, Ag powder is preferred.

[0155] Methods for producing metal powder other than water atomization include electrolysis, crushing, chemical reduction, heat treatment, and atomization methods such as gas atomization, disk atomization, and plasma atomization.

[0156] Metal powders produced by methods other than water atomization include metal powders made of Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals, and among these, Ag powder is preferred.

[0157] The metal powder produced by water atomization and the metal powder produced by a method other than water atomization may be different in type (composition), but it is preferable that they are the same. For example, when the metal powder produced by water atomization is Ag powder, it is preferable that the metal powder produced by a method other than water atomization is also Ag powder.

[0158] This specification describes the following:

[0159] The present disclosure (1) provides a laminate including a plurality of insulating layers stacked together and having an internal electrode, and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode includes a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, the first lead conductor and the second lead conductor extend in the stacking direction of the insulating layers, When the coil conductors that are directly connected to the first lead conductor are defined as a first coil conductor and the coil conductor that are directly connected to the second lead conductor are defined as a second coil conductor, The laminated coil component is characterized in that the pore area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are 1.00% or more and 11.00% or less, respectively.

[0160] The present disclosure (2) is the laminated coil component according to the present disclosure (1), in which the pore area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is greater than 11.00% and not greater than 20.00%.

[0161] The present disclosure (3) is the laminated coil component according to the present disclosure (2), in which the pore area ratio of all the coil conductors other than the first coil conductor and the second coil conductor is greater than 11.00% and not more than 20.00%.

[0162] The present disclosure (4) is a method for manufacturing a coil having a thickness of the first coil conductor that is larger than a maximum pore diameter of the first coil conductor, The laminated coil component is any combination of any of the present disclosures (1) to (3), in which the thickness of the second coil conductor is larger than the maximum pore diameter of the second coil conductor.

[0163] The present disclosure (5) is a laminated coil component in any combination with any of the present disclosures (1) to (4), in which the maximum pore diameters of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are smaller than the maximum pore diameters of the coil conductors other than the first coil conductor and the second coil conductor.

[0164] The present disclosure (6) is characterized in that the insulating layer contains ferrite, The pore area ratio of the insulating layer is 0.10% or more and 5.00% or less, and the laminated coil component is any combination with any of the present disclosures (1) to (5).

[0165] The present disclosure (7) is a laminated coil component in any combination with any of the present disclosures (1) to (5), in which the pore area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are 1.00% or more and 4.00% or less, respectively.

[0166] The present disclosure (8) provides a laminated body having an internal electrode formed by laminating a plurality of insulating layers, and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode includes a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, providing a ceramic green sheet including a ceramic material; a printing step of printing a conductive paste on a plurality of the ceramic green sheets to form a conductive paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor; a step of laminating a plurality of the ceramic green sheets on which the conductive paste layers are formed to produce an unfired laminate having an unfired coil built therein; and firing the unfired laminate to produce a laminate, When the coil conductors that are directly connected to the first lead conductor are defined as a first coil conductor and the coil conductor that are directly connected to the second lead conductor are defined as a second coil conductor, The method for manufacturing a laminated coil component is characterized in that the PVC of the conductor paste for the first coil conductor, the second coil conductor, the first lead conductor, and the second lead conductor is 45.00% or more and 55.00% or less.

[0167] The present disclosure (9) is the method for producing a laminated coil component according to the present disclosure (8), wherein the PVC of the conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less.

[0168] The present disclosure (10) is the method for producing a laminated coil component according to the present disclosure (9), wherein the PVC of the conductor paste for all the coil conductors other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less.

[0169] The present disclosure (11) provides a laminate including a plurality of insulating layers stacked together and having an internal electrode, and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode includes a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, providing a ceramic green sheet including a ceramic material; a printing step of printing a conductive paste on a plurality of the ceramic green sheets to form a conductive paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor; a step of laminating a plurality of the ceramic green sheets on which the conductive paste layers are formed to produce an unfired laminate having an unfired coil built therein; and firing the unfired laminate to produce a laminate, When the coil conductors that are directly connected to the first lead conductor are defined as a first coil conductor and the coil conductor that are directly connected to the second lead conductor are defined as a second coil conductor, the conductor paste for the first coil conductor, the second coil conductor, the first lead conductor, and the second lead conductor contains metal powder produced by a method other than water atomization, A method for manufacturing a laminated coil component, wherein the conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor contains metal powder produced by a water atomization method. [Example]

[0170] EXAMPLES Hereinafter, examples will be given that more specifically disclose the present invention, but the present invention is not limited to these examples.

[0171] (Preparation of Samples 1 to 6) According to the manufacturing method of the laminated coil component according to the first embodiment of the present invention, 100 pieces of each of Samples 1 to 6 (laminated coil components) were manufactured, each having a different composition (PVC) for the conductor paste (low pore conductor paste) for the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor, and a conductor paste (high pore conductor paste) for the coil conductor other than the first coil conductor and the second coil conductor (third coil conductor), as shown in Table 1. Table 1 shows the PVC of the conductor paste (low pore conductor) and the conductor paste (high pore conductor paste) used to manufacture each sample.

[0172] (Determining whether or not there is a break in the wire) The electrical properties (DC resistance) of all 100 samples were measured, and the presence or absence of disconnections was determined from the measurement results, and the number of samples with disconnections was counted. The results are shown in Table 1.

[0173] (Measurement of pore area ratio and maximum pore diameter) From the SEM images of the cross section of each sample, the pore area ratio and maximum pore diameter of the first drawn conductor, second drawn conductor, first coil conductor, and second coil conductor, as well as the average pore area ratio and maximum pore diameter of all coil conductors other than the first coil conductor and second coil conductor, were determined, and the average values ​​for 100 samples were calculated. The results are shown in Table 1.

[0174] [Table 1]

[0175] As shown in Table 1, the pore area ratios of the first extension conductor, second extension conductor, first coil conductor, and second coil conductor were the same for each sample. Similarly, the maximum pore diameters of the first extension conductor, second extension conductor, first coil conductor, and second coil conductor were also the same for each sample. From the results in Table 1, it was confirmed that by setting the PVC of the conductor paste to 45.00% or more and 55.00% or less, the pore area ratio of the resulting conductor becomes 1.00% or more and 11.00% or less. Similarly, it was confirmed that by setting the PVC content of the conductor paste to 30.00% or more and 40.00% or less, the pore area ratio of the resulting conductor was greater than 11.00% and less than 20.00%.

[0176] It was confirmed that no disconnections occurred in Samples 1 to 4, in which the pore area ratios of the first extract conductor, second extract conductor, first coil conductor, and second coil conductor were 1.00% or more and 11.00% or less. On the other hand, it was confirmed that disconnections may occur near the connection (bent portion) between the first extract conductor and the coil conductor and / or the connection (bent portion) between the second extract conductor and the coil conductor in Samples 5 and 6, in which the pore area ratios of the first extract conductor, second extract conductor, first coil conductor, and second coil conductor were more than 11.00%. Furthermore, it was confirmed that, in the samples in which disconnections occurred among Samples 5 to 6, pores were concentrated at the connection between the first extract conductor and the first coil conductor or the connection between the second extract conductor and the second coil conductor. From the above results, it was confirmed that the laminated coil component of the present invention can reduce the risk of breakage of the lead-out connection portion. In addition, for sample 1, in which the pore area ratio of the first extraction conductor, second extraction conductor, first coil conductor, and second coil conductor is 4.00% or less, the maximum pore diameter is approximately 3.3 μm, which is thought to not only reduce the risk of breakage but also suppress current concentration, thereby ensuring reliable conductivity. [Explanation of symbols]

[0177] 1, 1', 3, 5 Multilayer coil components 10, 10', 60, 70 laminate 11 First end surface 12 Second end face 13 First main surface 14 Second main surface 15 First aspect 16 Second aspect 21 1st external electrode 22 2nd external electrode 30, 130, 230 coils 31, 31a, 31b, 31c, 31d, 31e, 31f, 131, 131a, 131b, 131c, 132d, 132g, 131h, 131i Insulating layer 32, 32a, 32b, 32c, 32d Coil conductors 33, 33a, 33a1, 33a2, 33a3, 33b, 33c, 33d, 33e, 33f via conductors 34, 34a, 34b, 34c, 34d Circumference section 35, 35a, 35b, 35c, 35d, 35e, 35f Land 41 First lead-out conductor 42 Second lead-out conductor 50, 55 pores 132a, 132a1, 132a2, 132a3 First coil conductor 131a11, 132a21: Portions of the first coil conductor sandwiched between the via conductors (parts of the first lead conductor) 132d, 132d1, 132d2 Second coil conductor 132d21 Portion of the second coil conductor sandwiched between the via conductors (part of the second lead-out conductor) A Coil shaft

Claims

1. a laminate formed by laminating a plurality of insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode includes a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, When the coil conductors that are directly connected to the first lead conductor are defined as a first coil conductor and the coil conductor that are directly connected to the second lead conductor are defined as a second coil conductor, the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor each have a pore area ratio of 1.00% or more and 11.00% or less.

2. 2. The laminated coil component according to claim 1, wherein a pore area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is greater than 11.00% and is not greater than 20.00%.

3. 3. The laminated coil component according to claim 2, wherein the pore area ratio of all the coil conductors other than the first coil conductor and the second coil conductor is greater than 11.00% and is not greater than 20.00%.

4. a thickness of the first coil conductor is greater than a maximum pore diameter of the first coil conductor; The laminated coil component according to claim 1 , wherein the thickness of the second coil conductor is larger than the maximum pore diameter of the second coil conductor.

5. 3. The laminated coil component according to claim 1, wherein the maximum pore diameters of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are each smaller than the maximum pore diameters of the coil conductors other than the first coil conductor and the second coil conductor.

6. the insulating layer comprises ferrite; 3. The laminated coil component according to claim 1, wherein the insulating layer has a pore area ratio of 0.10% or more and 5.00% or less.

7. 3. The laminated coil component according to claim 1, wherein the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor each have a pore area ratio of 1.00% or more and 4.00% or less.

8. a laminate formed by laminating a plurality of insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode includes a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, a manufacturing method of a laminated coil component, wherein the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, providing a ceramic green sheet including a ceramic material; a printing step of printing a conductive paste on a plurality of the ceramic green sheets to form a conductive paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor; a step of laminating a plurality of the ceramic green sheets on which the conductive paste layers are formed to produce an unfired laminate having an unfired coil built therein; and firing the unfired laminate to produce a laminate, When the coil conductors that are directly connected to the first lead conductor are defined as a first coil conductor and the coil conductor that are directly connected to the second lead conductor are defined as a second coil conductor, a PVC of the conductor paste for the first coil conductor, the second coil conductor, the first lead conductor, and the second lead conductor is 45.00% or more and 55.00% or less.

9. 9. The method for producing a laminated coil component according to claim 8, wherein a PVC of a conductor paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less.

10. 10. The method for producing a laminated coil component according to claim 9, wherein PVC of the conductor paste for all of the coil conductors other than the first coil conductor and the second coil conductor is 30.00% or more and 40.00% or less.

11. a laminate formed by laminating a plurality of insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode includes a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, a first lead conductor connecting the coil and the first external electrode, and a second lead conductor connecting the coil and the second external electrode, a manufacturing method of a laminated coil component, wherein the first lead conductor and the second lead conductor extend in a stacking direction of the insulating layers, providing a ceramic green sheet including a ceramic material; a printing step of printing a conductive paste on a plurality of the ceramic green sheets to form a conductive paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor; a step of laminating a plurality of the ceramic green sheets on which the conductive paste layers are formed to produce an unfired laminate having an unfired coil built therein; and firing the unfired laminate to produce a laminate, When the coil conductors that are directly connected to the first lead conductor are defined as a first coil conductor and the coil conductor that are directly connected to the second lead conductor are defined as a second coil conductor, the conductor paste for the first coil conductor, the second coil conductor, the first lead conductor, and the second lead conductor contains metal powder produced by a method other than water atomization, a conductive paste for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor contains metal powder produced by a water atomization method.

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