Laminated coil component and method for manufacturing laminated coil component

Abstract

This laminated coil component is provided with: a laminated body which is obtained by laminating a plurality of insulating layers and which has internal electrodes; and a first external electrode and a second external electrode electrically connected to the internal electrode, the internal electrode including: a coil formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer; a first lead-out conductor connecting the coil and the first external electrode; and a second lead-out conductor connecting the coil and the second external electrode, the first lead-out conductor and the second lead-out conductor extending in the stacking direction of the insulating layers, the coil conductor directly connected to the first lead-out conductor among the coil conductors being a first coil conductor, and the coil conductor directly connected to the second lead-out conductor among the coil conductors being a second coil conductor. When the coil conductor directly connected to the second lead-out conductor is the second coil conductor, the pore area ratios of the first lead-out conductor, the second lead-out conductor, the first coil conductor, and the second coil conductor are respectively 1.00% or more and 11.00% or less.

Description

Technical Field

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

[0002] For example, Patent Document 1 discloses a stacked electronic component in which a coil is formed inside by stacking an insulating layer composed of a coil conductor and a magnetic or non-magnetic body, and terminal electrodes are provided at both ends in the stacking direction. The terminal electrode on at least one end side is connected to the coil end inside the stack via a conductor-filled through-hole provided in one or more insulating layers and a lead-out electrode provided to cover the end of the through-hole. The area of ​​the lead-out electrode is set to be more than three times the cross-sectional area of ​​the through-hole and less than 1 / 3 of the area inside the coil when the stack is viewed through the stack in the stacking direction.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-15918

[0004] In a laminated inductor (laminated coil component), it is required to improve the connectivity between the internal electrode and the external electrode at the lead portion.

[0005] However, in the stacked coil component described in Patent Document 1, which has a transversely wound electrode with external electrodes led out at both ends in the stacking direction of the insulating layer, the switching portion (also called the lead-out connection portion) between the coil conductor and the lead-out electrode (also called the lead-out conductor) is bent, and there is a problem that the wire is easily broken at this bent portion.

[0006] This is believed to be because bubbles (voids) are generated inside the conductor paste when the conductor paste for forming the coil conductor and the lead electrode is fired, and the bubbles generated inside the conductor paste near the lead electrode are sucked to the outside.

[0007] That is, it is believed that there is no external electrode during firing and the lead-out electrode is exposed. Therefore, the bubbles generated in the coil conductor near the exposed part of the lead-out electrode are attracted to the outside, resulting in the bubbles being concentrated in the bent part (lead-out connection part) which becomes the switching part between the coil conductor and the lead-out electrode, thereby causing the lead-out connection part to be broken. Summary of the Invention

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a laminated coil component and a method for manufacturing the laminated coil component, which can reduce the risk of disconnection of a lead-out connection portion.

[0009] The stacked coil component of the present invention is characterized in that it comprises: a stacked body formed by stacking multiple insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the above-mentioned internal electrode, the above-mentioned internal electrode including: a coil formed by electrically connecting multiple coil conductors stacked together with the above-mentioned insulating layer; a first lead-out conductor connecting the above-mentioned coil and the above-mentioned first external electrode; and a second lead-out conductor connecting the above-mentioned coil and the above-mentioned second external electrode, the above-mentioned first lead-out conductor and the above-mentioned second lead-out conductor extending in the stacking direction of the above-mentioned insulating layer, and among the above-mentioned coil conductors, when the coil conductor directly connected to the above-mentioned first lead-out conductor is set as the first coil conductor and the coil conductor directly connected to the above-mentioned second lead-out conductor is set as the second coil conductor, the porosity area ratios of the above-mentioned first lead-out conductor, the above-mentioned second lead-out conductor, the above-mentioned first coil conductor and the above-mentioned second coil conductor are respectively greater than 1.00% and less than 11.00%.

[0010] In a method for manufacturing a stacked coil component according to a first embodiment of the present invention, the stacked coil component comprises: a stacked body formed by stacking 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 comprising: 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 extending in the stacking direction of the insulating layer, and is characterized in that the method for manufacturing a stacked coil component comprises the following steps: a step of preparing a ceramic green sheet comprising a ceramic material; a step of stacking a plurality of ceramic green sheets ... A step of printing a conductor paste on the ceramic green sheet to form a conductor paste layer that becomes the coil conductor, the first lead conductor and / or the second lead conductor; a step of making an unfired laminated body in which a plurality of the ceramic green sheets formed with the conductor paste layer are stacked and an unfired coil is built in; and a step of firing the unfired laminated body to make a laminated body, wherein, among the coil conductors, the coil conductor directly connected to the first lead conductor is set as the first coil conductor, and the coil conductor directly connected to the second lead conductor is set as the second coil conductor, the PVC of the conductor paste used for the first coil conductor, the second coil conductor, the first lead conductor and the second lead conductor is greater than 45.00% and less than 55.00%.

[0011] In the manufacturing method of the stacked coil component of the second embodiment of the present invention, the stacked coil component comprises: a stacked body formed by stacking a plurality of insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the above-mentioned internal electrode, the above-mentioned internal electrode comprising: a coil formed by electrically connecting a plurality of coil conductors stacked together with the above-mentioned insulating layer; a first lead-out conductor connecting the above-mentioned coil and the above-mentioned first external electrode; and a second lead-out conductor connecting the above-mentioned coil and the above-mentioned second external electrode, the above-mentioned first lead-out conductor and the above-mentioned second lead-out conductor extending in the stacking direction of the above-mentioned insulating layer, and is characterized in that the manufacturing method of the stacked coil component comprises the following steps: a step of preparing ceramic green sheets containing ceramic material; a step of printing conductor paste on the plurality of the above-mentioned ceramic green sheets to form the above-mentioned coil conductor, A step of printing a conductor paste layer of the above-mentioned first lead conductor and / or the above-mentioned second lead conductor; a step of producing an unfired laminated body in which a plurality of the above-mentioned ceramic green sheets formed with the above-mentioned conductor paste layer are stacked and an unfired coil is built in; and a step of firing the above-mentioned unfired laminated body to produce a laminated body, wherein, among the above-mentioned coil conductors, the coil conductor directly connected to the above-mentioned first lead conductor is set as the first coil conductor, and the coil conductor directly connected to the above-mentioned second lead conductor is set as the second coil conductor, the conductor paste used for the above-mentioned first coil conductor, the above-mentioned second coil conductor, the above-mentioned first lead conductor and the above-mentioned second lead conductor contains metal powder manufactured by a method other than the water atomization method, and the conductor paste used for at least one layer of the above-mentioned coil conductors other than the above-mentioned first coil conductor and the above-mentioned second coil conductor contains metal powder manufactured by the water atomization method.

[0012] According to the present invention, it is possible to provide a laminated coil component and a method for manufacturing the laminated coil component that can reduce the risk of disconnection of a lead-out connection portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view schematically showing an example of the laminated coil component according to the first embodiment of the present invention.

[0014] Figure 2 It schematically represents the composition Figure 1 1 is an exploded perspective view of an example of a laminated body of the laminated coil component shown.

[0015] Figure 3 It is a perspective composition Figure 1 1 is a side view schematically showing an example of the internal structure of a laminated body of the laminated coil component shown.

[0016] Figure 4 It is schematically represented Figure 1 1 is a cross-sectional view of an example of a cross section of the laminated coil component taken along line segment A1 - A1 .

[0017] Figure 5 It is schematically represented Figure 1 1 is a cross-sectional view of an example of a cross section of the laminated coil component taken along line segment A2 - A2 .

[0018] Figure 6 This is a cross-sectional view schematically showing an example of a laminated coil component that does not satisfy the characteristics of the present invention.

[0019] Figure 7 It is an exploded perspective view schematically showing an example of a laminated body constituting an example of a laminated coil component according to the second embodiment of the present invention.

[0020] Figure 8 Is perspective Figure 7 1 is a side view schematically showing the state of the voids in the internal electrodes of the laminated coil component of the laminate shown.

[0021] Figure 9 It is a perspective view schematically showing an example of a laminated coil component according to a third embodiment of the present invention.

[0022] Figure 10 It schematically represents the composition Figure 9 1 is an exploded perspective view of an example of a laminated body of the laminated coil component shown.

[0023] Figure 11 It is schematically represented Figure 9 1 is a cross-sectional view of an example of a cross section of the laminated coil component taken along line segment A3 - A3 .

[0024] Description of Reference Signs

[0025] 1, 1', 3, 5... Laminated coil component; 10, 10', 60, 70... Laminated body; 11... First end surface; 12... Second end surface; 13... First principal surface; 14... Second principal surface; 15... First side surface; 16... Second side surface; 21... First external electrode; 22... Second external electrode; 30, 130, 230... Coil; 31, 31a, 31b, 31c, 31d, 31e, 31f, 131, 131a, 131b, 131c, 132d, 132g, 131h, 131i... Insulating layer; 32, 32a, 32b, 32c, 32d... Coil conductor; 33, 33a, 33a1, 33a2, 33a3, 33b, 33c, 33i... 3d, 33e, 33f…through-hole conductor; 34, 34a, 34b, 34c, 34d…winding portion; 35, 35a, 35b, 35c, 35d, 35e, 35f…solder pad; 41…first lead-out conductor; 42…second lead-out conductor; 50, 55…aperture; 132a, 132a1, 132a2, 132a3…first coil conductor; 131a11, 132a21…portion of the first coil conductor sandwiched by the through-hole conductor (portion of the first lead-out conductor); 132d, 132d1, 132d2…second coil conductor; 132d21…portion of the second coil conductor sandwiched by the through-hole conductor (portion of the second lead-out conductor); A…coil axis. DETAILED DESCRIPTION

[0026] The following describes a laminated coil component and a method for manufacturing a laminated coil component of the present invention. It should be noted that the present invention is not limited to the following structure and may be appropriately modified without departing from the scope of the present invention. Furthermore, a structure obtained by combining multiple preferred structures described below also encompasses the present invention.

[0027] The accompanying drawings shown below are schematic diagrams, and their dimensions, aspect ratios, and scales may differ from those of actual products. In the drawings, identical or corresponding parts are denoted by the same reference numerals. In addition, in each drawing, identical elements are denoted by the same reference numerals and repeated descriptions are omitted.

[0028] In this specification, terms indicating the relationship between elements (for example, "parallel", "orthogonal", etc.) and terms indicating the shape of elements mean not only strict terms like words, but also essentially the same range, for example, a range containing a difference of about several percent.

[0029] The embodiments described below are merely illustrative. It is naturally possible to partially substitute or combine the structures shown in different embodiments. Following the second embodiment, descriptions of matters common to the first embodiment are omitted, and only the differences are described. In particular, similar effects based on similar structures are not mentioned sequentially in each embodiment.

[0030] [Laminated coil components]

[0031] The stacked coil component of the present invention is characterized in that it comprises: a stacked body formed by stacking multiple insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the above-mentioned internal electrode, the above-mentioned internal electrode including: a coil formed by electrically connecting multiple coil conductors stacked together with the above-mentioned insulating layer; a first lead-out conductor connecting the above-mentioned coil and the above-mentioned first external electrode; and a second lead-out conductor connecting the above-mentioned coil and the above-mentioned second external electrode, the above-mentioned first lead-out conductor and the above-mentioned second lead-out conductor extending in the stacking direction of the above-mentioned insulating layer, when the coil conductor directly connected to the above-mentioned first lead-out conductor among the above-mentioned coil conductors is set as the first coil conductor, and the coil conductor directly connected to the above-mentioned second lead-out conductor is set as the second coil conductor, the porosity area ratios of the above-mentioned first lead-out conductor, the above-mentioned second lead-out conductor, the above-mentioned first coil conductor and the above-mentioned second coil conductor are respectively greater than 1.00% and less than 11.00%.

[0032] Figure 1 It is a perspective view schematically showing an example of the laminated coil component according to the first embodiment of the present invention.

[0033] Figure 1 The illustrated laminated coil component 1 includes a laminate (green body) 10, and a first external electrode 21 and a second external electrode 22 provided on the outer surfaces of the laminate 10. The laminate 10 is a rectangular parallelepiped with six faces. The structure of the laminate 10 will be described later. Multiple insulating layers are stacked in the stacking direction, and a first lead conductor, a second lead conductor, and a coil are provided within the laminate as 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.

[0034] In the laminated coil component and the laminated body in this specification, the length direction, height direction, and width direction are referred to as Figure 1 Here, the length direction L, the height direction T, and the width direction W are perpendicular to each other.

[0035] Here, the longitudinal direction L is a direction parallel to the stacking direction.

[0036] like Figure 1 As shown, the stack 10 has: a first end face 11 and a second end face 12 opposite to each other in the length direction L; a first main face 13 and a second main face 14 opposite to each other in the height direction T perpendicular to the length direction L; and a first side face 15 and a second side face 16 opposite to each other in the width direction W perpendicular to the length direction L and the height direction T.

[0037] exist Figure 1 Although not shown, it is preferred that the laminate 10 have rounded corners and ridges. A corner is a portion where three sides of the laminate intersect, and a ridge is a portion where two sides of the laminate intersect.

[0038] For example, Figure 1 As shown, the first external electrode 21 covers the entire first end surface 11 of the laminate 10 and extends from the first end surface 11 to cover a portion of the first main surface 13 , a portion of the second main surface 14 , a portion of the first side surface 15 , and a portion of the second side surface 16 .

[0039] For example, Figure 1 As shown, the second external electrode 22 covers the entire second end surface 12 of the laminate 10 and extends from the second end surface 12 to cover a portion of the first main surface 13 , a portion of the second main surface 14 , a portion of the first side surface 15 , and a portion of the second side surface 16 .

[0040] When the laminated coil component 1 provided with the first external electrode 21 and the second external electrode 22 is mounted on a substrate as described above, any one of the first principal surface 13 , the second principal surface 14 , the first side surface 15 , and the second side surface 16 of the laminate 10 serves as a mounting surface.

[0041] However, the first external electrode 21 only needs to extend from at least a portion of the first end surface 11 of the stacked body 10 to the mounting surface of the stacked body 10 .

[0042] Likewise, the second external electrode 22 only needs to extend from at least a portion of the second end surface 12 of the stacked body 10 to the mounting surface of the stacked body 10 .

[0043] Each of the first external electrode 21 and the second external electrode 22 may have a single-layer structure or a multi-layer structure.

[0044] When the first external electrode 21 and the second external electrode 22 each have a single-layer structure, examples of the structural material of each external electrode include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0045] When the first external electrode 21 and the second external electrode 22 each have a multilayer structure, each external electrode may include, for example, a base electrode layer containing Ag, a Ni film, and a Sn film in this order from the surface side of the laminate 10 .

[0046] 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.

[0047] Figure 2It schematically represents the composition Figure 1 1 is an exploded perspective view of an example of a laminated body of the laminated coil component shown.

[0048] like Figure 2 As shown, the laminate 10 is constructed by stacking a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in a stacking direction (here, the longitudinal direction L) from the first end face 11 side toward the second end face 12 side of the laminate 10. Hereinafter, the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f are also collectively referred to as insulating layers 31.

[0049] In this specification, the direction in which a plurality of insulating layers constituting a laminate is stacked is referred to as a stacking direction.

[0050] exist Figure 2 In the embodiment, the insulating layer 31e is arranged on the lower side in the stacking direction (the first end face 11 side of the stacked body 10), and the insulating layer 31f is arranged on the upper side in the stacking direction (the second end face 12 side of the stacked body 10).

[0051] As a structural material of each insulating layer 31, a magnetic material such as a ferrite material is mentioned, for example.

[0052] Coil conductors 32a, 32b, 32c, and 32d, and through-hole conductors 33a, 33b, 33c, and 33d are provided on insulating layers 31a, 31b, 31c, and 31d, respectively. Through-hole conductors 33e and pads 35e are provided on insulating layer 31e. Through-hole conductors 33f and pads 35f are provided on insulating layer 31f. Insulating layer 31e may have one layer or two or more layers. Similarly, insulating layer 31f may have one layer or two or more layers. Hereinafter, coil conductors 32a, 32b, 32c, and 32d may be collectively referred to as coil conductors 32.

[0053] The coil conductors 32a, 32b, 32c, and 32d are provided on the main surfaces of the insulating layers 31a, 31b, 31c, and 31d, respectively, and are stacked together with the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f. Figure 2 In the embodiment, each coil conductor 32 has a 3 / 4 turn shape, and four insulating layers 31 arranged in this order, 31a, 31b, 31c, and 31d, are repeatedly stacked as one unit (3 turns).

[0054] Coil conductors 32a, 32b, 32c, and 32d each include annular winding portions 34a, 34b, 34c, and 34d, each having a partially missing portion and a gap, as well as solder pads 35a, 35b, 35c, and 35d. Solder pads 35a, 35b, 35c, and 35d are provided at both ends of each winding portion 34a, 34b, 34c, and 34d, respectively. Hereinafter, winding portions 34a, 34b, 34c, and 34d are collectively referred to as winding portion 34.

[0055] Via conductors 33a, 33b, 33c, 33d, 33e, and 33f are provided so as to penetrate insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in the stacking direction, respectively.

[0056] Solder pads 35e and 35f are provided directly above via-hole conductors 33e and 33f, respectively. Solder pads 35a, 35b, 35c, 35d, 35e, and 35f are preferably slightly wider than the line width of wound portions 34a, 34b, 34c, and 34d. Hereinafter, solder pads 35a, 35b, 35c, 35d, 35e, and 35f are collectively referred to as solder pads 35.

[0057] Examples of the structural material of each coil conductor 32 including the winding portion 34 and the pad 35 and each via-hole conductor 33 include Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals.

[0058] The plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f constructed as described above are stacked in the stacking direction. This forms the laminate 10, with the plurality of coil conductors 32a, 32b, 32c, and 32d electrically connected via the via-hole conductors 33a, 33b, 33c, and 33d. As a result, a solenoid-shaped coil having a coil axis parallel to the stacking direction is formed within the laminate 10.

[0059] Furthermore, through-hole conductors 33a and 33e, as well as pads 35e, provided in insulating layer 31a, which includes coil conductor 32 closest to first end face 11, form first lead conductors within laminate 10 and are exposed at first end face 11 of laminate 10. Specifically, the first lead conductors include through-hole conductors 33e and 33a, and pads 35e. As will be described later, the first lead conductors connect the first external electrode 21 to the coil conductor 32a facing the first external electrode 21 within laminate 10.

[0060] The through-hole conductor 33f and the pad 35f form a second lead conductor within the laminate 10, exposed at the second end surface 12 of the laminate 10. That is, the second lead conductor includes the through-hole conductor 33f and the pad 35f. As will be described later, the second lead conductor connects the second external electrode 22 to the coil conductor 32d opposing the second external electrode 22 within the laminate 10.

[0061] When viewed from the stacking direction (longitudinal direction L), the coil conductors 32 are preferably overlapped with each other. Figure 2 The shape composed of straight line portions (for example, a polygonal shape such as a rectangle) as shown may be a shape composed of curved line portions (for example, a circle), or a shape composed of both straight line portions and curved line portions.

[0062] Figure 3 It is a perspective composition Figure 1 1 is a side view schematically showing an example of the internal structure of a laminated body of the laminated coil component shown.

[0063] like Figure 3 As shown, in the laminated coil component 1, a plurality of insulating layers 31 are laminated in the longitudinal direction L, so the longitudinal direction L is the lamination direction. In addition, the lamination 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 serving as the mounting surface.

[0064] In addition, if Figure 3 As shown, no boundary is actually visually confirmed between adjacent insulating layers 31 .

[0065] The first lead conductor 41 extends within the laminate 10 in the stacking direction, linearly connecting the first external electrode 21 provided on the first end face 11 and the coil conductor 32a opposite thereto. Similarly, the second lead conductor 42 extends within the laminate 10 in the stacking direction, linearly connecting the second external electrode 22 provided on the second end face 12 and the coil conductor 32d opposite thereto.

[0066] Here, the coil conductor 32a connected to the first lead conductor 41 extends in a direction perpendicular to the stacking direction relative to the first lead conductor 41. Therefore, it can be said that the first lead conductor 41 and the switching portion (lead-out connection portion) of the coil conductor 32a connected to the first lead conductor 41 are bent. Similarly, the coil conductor 32d connected to the second lead conductor 42 extends in a direction perpendicular to the stacking direction relative to the second lead conductor 42. Therefore, it can be said that the second lead conductor 42 and the switching portion (lead-out connection portion) of the coil conductor 32d connected to the second lead conductor 42 are bent.

[0067] Furthermore, it is preferable that the via-hole conductors constituting the lead conductors overlap with each other when viewed in the stacking direction (longitudinal direction L), but the via-hole conductors constituting the lead conductors do not necessarily need to be arranged in a strictly linear manner.

[0068] In addition, Figure 2 as well as Figure 3 , the case where the number of stacking layers of the coil conductor 32 for constituting three turns of the coil 30 is four, that is, the case where the repeated shape is a 3 / 4 turn shape, but the number of stacking layers of the coil conductor 32 for constituting one turn of the coil 30 is not particularly limited.

[0069] For example, the number of stacked layers of the coil conductor 32 constituting one turn of the coil 30 may be two, that is, the repeated shape may be a 1 / 2 turn shape.

[0070] The number of stacked layers of the coil conductors 32 , that is, the number of stacked layers of all the coil conductors 32 included in the laminate 10 , is not particularly limited, but is preferably 30 or more and 120 or less.

[0071] Figure 4 It is schematically represented Figure 1 1 is a cross-sectional view of an example of a cross section of the laminated coil component taken along line segment A1 - A1 . Figure 4 It will also Figure 1 The laminated coil component shown is cut at a position overlapping the first lead conductor and the second lead conductor, so that the LW plane is exposed.

[0072] Figure 5 It is schematically represented Figure 1 1 is a cross-sectional view of an example of a cross section of the laminated coil component taken along line segment A2 - A2 . Figure 5 It will also Figure 1 The laminated coil component shown is cut at a position overlapping with the first lead conductor and the second lead conductor, so that the LT plane is exposed.

[0073] like Figure 4 As shown, the coil conductor 32 that is directly connected to the first lead conductor 41 is the first coil conductor 132 a .

[0074] like Figure 5 As shown, the coil conductor 32 that is directly connected to the second lead conductor 42 is the second coil conductor 132 d .

[0075] Therefore, the laminated body 10 includes one layer of the first coil conductor 132 a and one layer of the second coil conductor 132 d .

[0076] In addition, the coil conductors other than the first coil conductor 132a and the second coil conductor 132d in the coil conductor 32 are also referred to as third coil conductors.

[0077] like Figure 4 as well as Figure 5 As shown, holes 50 are formed in the pads 35e and through-hole conductors 33e and 33a that constitute the first lead conductor 41, and in the pads 35f and through-hole conductor 33f that constitute the second lead conductor 42. Furthermore, holes 50 are formed in the first coil conductor 132a and the second coil conductor 132d. Similarly, holes 50 are formed in the coil conductor 32 (third coil conductor) other than the first coil conductor 132a and the second coil conductor 132d, and in the through-hole conductors 33a, 33b, 33c, and 33d that connect the third coil conductors.

[0078] The size of the aperture may be the same in the first lead conductor, the second lead conductor, the first coil conductor, the second coil conductor, and the coil conductor other than the first coil conductor and the second coil conductor (the third coil conductor). Figure 4 as well as Figure 5 In the embodiment, the size of the pores 50 formed in the first lead conductor 41, the second lead 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 conductor 32 (third coil conductor) other than the first coil conductor 132a and the second coil conductor 132d and the through-hole conductors 33a, 33b, 33c and 33d connecting the third coil conductors to each other.

[0079] In addition, Figure 4 as well as Figure 5 In the embodiment, the pores 50 are not exposed outside the conductor (at the boundary between the conductor and the insulating layer). However, the pores 50 may be exposed outside the conductor and in contact with the insulating layer 31 .

[0080] exist Figure 4 as well as Figure 5 In the illustrated laminated body 10 , the first lead conductor 41 , the second lead conductor 42 , the first coil conductor 132 a , and the second coil conductor 132 d each have a void area ratio of 1.00% to 11.00%.

[0081] If the porosity area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are respectively greater than 1.00% and less than 11.00%, the pores are less likely to be concentrated in the curved portion (lead connection portion) that serves as the switching portion between the coil conductor and the lead conductor, thereby reducing the risk of wire breakage.

[0082] If the void area ratio of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor is less than 1.00%, the coil conductors undergo excessive thermal contraction, increasing residual stress between the coil conductors and the insulating layer, making cracks more likely to form.

[0083] The porosity area ratio refers to the ratio of the area occupied by pores (voids, pores) per unit area of ​​the internal electrode formed by sintering the conductive paste.

[0084] An image of the entire cross-section of the stacked coil component in a plane extending along the stacking direction of the insulating layer and passing through the center of the lead conductor is obtained using an electron microscope, and the resulting image is analyzed using commercially available image analysis software (for example, Eizo-kun (registered trademark) manufactured by Asahi Kasei Engineering Corporation), thereby determining the porosity area ratio.

[0085] Specifically, for example, by using image analysis software to distinguish between the aperture and conductor portions in a predetermined region of the internal electrode (e.g., the region corresponding to the first lead conductor) through binarization or the like, and finding the ratio of the area of ​​the aperture to the total area of ​​the aperture and conductor, the aperture area ratio can be calculated. In the case where the first lead conductor 41 and the second lead conductor are not located in the same cross-section, it is sufficient to obtain two images each of a cross-section of the laminated coil component taken along a plane perpendicular to the direction of stacking of the insulating layers and passing through the center of the first lead conductor 41, and a cross-section of the laminated coil component taken along a plane perpendicular to the direction of stacking of the insulating layers and passing through the center of the second lead conductor 42.

[0086] Figure 6 This is a cross-sectional view schematically showing an example of a laminated coil component that does not satisfy the characteristics of the present invention.

[0087] exist Figure 6 In the laminated coil component 1' shown, the first lead conductor 41, the second lead conductor 42, and the first coil conductor 132a each have a void area ratio exceeding 11.00%. Although not shown, the second coil conductor also has a void area ratio exceeding 11.00%.

[0088] Therefore, if Figure 6 As shown, the voids 50 are concentrated at the connection portion (bend portion) between the first lead conductor 41 and the first coil conductor 132a and the connection portion (bend portion) between the second lead conductor 42 and the second coil conductor 132d, increasing the risk of disconnection.

[0089] The first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor may each have a void area ratio of 1.00% to 4.00%.

[0090] If the porosity area ratios of the first lead conductor, second lead conductor, first coil conductor, and second coil conductor are each 1.00% or higher and 4.00% or lower, porosity is less likely to concentrate in the curved portion (lead connection portion) that serves as the transition point between the coil conductor and the lead conductor. This not only reduces the risk of disconnection but also prevents the current path from being extremely narrowed (current concentration) due to concentrated porosity, even though disconnection is unlikely. This ensures reliable conduction.

[0091] The thickness of the first coil conductor may be larger than the maximum hole diameter in the first coil conductor.

[0092] If the thickness of the first coil conductor is larger than the maximum pore diameter in the first coil conductor, the first coil conductor will not be disconnected in the largest pore cell, and thus the risk of disconnection due to the pores can be further reduced.

[0093] The thickness of the second coil conductor may be larger than the maximum hole diameter in the second coil conductor.

[0094] If the thickness of the second coil conductor is larger than the maximum pore diameter in the second coil conductor, the second coil conductor will not be disconnected in the largest pore cell, and thus the risk of disconnection due to the pores can be further reduced.

[0095] The pore diameter refers to the area of ​​each pore converted into the diameter of an area-equivalent circle.

[0096] In addition, the maximum pore diameter refers to the largest pore diameter among the pore diameters calculated from all the pores existing in the region.

[0097] For example, the maximum pore diameter in the first coil conductor is obtained by converting the area of ​​the largest pore (largest pore) among the pores existing in the first coil conductor in a specific cross section into the diameter of an area-equivalent circle.

[0098] In addition, in the cross-sectional view of the stacked coil component used when measuring the aperture, the thickness of the first coil conductor is calculated by dividing the total area of ​​the first coil conductor (the sum of the area of ​​the conductor portion and the area of ​​the aperture portion) by the dimension of the first coil conductor in a direction perpendicular to the stacking direction of the insulating layer.

[0099] The thickness of the second coil conductor is also determined in the same way.

[0100] The maximum hole diameter in the first coil conductor is preferably 70% or less, more preferably 50% or less, of the thickness of the first coil conductor. The maximum hole diameter in the first coil conductor is preferably 10% or more, more preferably 30% or more of the thickness of the first coil conductor.

[0101] The maximum hole diameter in the second coil conductor is preferably 70% or less, more preferably 50% or less, of the thickness of the second coil conductor. The maximum hole diameter in the second coil conductor is preferably 10% or more, more preferably 30% or more of the thickness of the second coil conductor.

[0102] It is preferable that the void area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor (third coil conductor) is larger than the void area ratios of the first coil conductor and the second coil conductor.

[0103] It is preferable that the void area ratio of at least one layer of the first coil conductor and the third coil conductor, which is a coil conductor other than the second coil conductor, is greater than 11.00% and is 20.00% or less.

[0104] Coil conductors with a porosity ratio exceeding 11.00% and below 20.00% can be said to experience a high shrinkage rate during sintering. If at least one layer of the third coil conductor is such a coil conductor, the shrinkage rate of the insulation layer can be made close to that of the coil conductor during sintering of the laminate. This can suppress degradation of the coil's electrical properties caused by the difference in shrinkage between the insulation layer and the coil conductor.

[0105] Furthermore, the coil conductors other than the first and second coil conductors (the third coil conductor) are connected to the first or second lead conductor via the winding portion of the first or second coil conductor. Therefore, the distance to the bend is greater than that of the first or second coil conductor. Therefore, the porosity formed in the third coil conductor is unlikely to cause the bend to shift during firing. Therefore, even if the porosity area ratio of the third coil conductor exceeds 11.00%, there is no increased risk of disconnection at the bend (lead connection).

[0106] On the other hand, among the coil conductors other than the first coil conductor and the second coil conductor, i.e., the third coil conductor, when there is no layer of coil conductor with a porosity ratio of less than 20.00%, that is, when the porosity ratio of all the third coil conductors exceeds 20.00%, the Rdc (internal resistance) of the internal electrode, i.e., the coil becomes high.

[0107] In other words, it is preferable that the void area ratio of all coil conductors other than the first coil conductor and the second coil conductor, that is, all third coil conductors, is 20.00% or less.

[0108] The void area ratio of two or more layers of the third coil conductor may be greater than 11.00% and 20.00% or less, and a coil conductor having a void area ratio of 11.00% or less may exist in part of the third coil conductor.

[0109] However, the number of layers of the third coil conductor having a void area ratio of 11.00% or less is preferably smaller than the number of layers of the third coil conductor having a void area ratio exceeding 11.00% and being 20.00% or less.

[0110] When the number of layers of all third coil conductors is 100%, it is preferable that the void area ratio of 50% or more of the layers of the third coil conductors exceeds 11.00% and is 20.00% or less.

[0111] In the case where the first coil conductor and the third coil conductor other than the second coil conductor include both a coil conductor having a void area ratio of 11.00% or less and a coil conductor having a void area ratio of more than 1.00% and less than 20.00%, the arrangement (configuration) of the coil conductor having a void area ratio of 11.00% or less and the coil conductor having a void area ratio of more than 11.00% and less than 20.00% is not particularly limited. The coil conductor having a void area ratio of 11.00% or less is preferably arranged at a position closer to the first coil conductor or the second coil conductor than the coil conductor having a void area ratio of more than 11.00% and less than 20.00%, and is more preferably arranged at a position adjacent to the first coil conductor or the second coil conductor in the stacking direction.

[0112] It is preferable that the void area ratio of all coil conductors other than the first coil conductor and the second coil conductor, that is, all third coil conductors, exceeds 11.00% and is 20.00% or less.

[0113] If the porosity area ratio of all third coil conductors exceeds 11.00% and is less than 20.00%, all coil conductors other than the first and second coil conductors are composed of coil conductors with a high shrinkage rate during sintering. Therefore, when the laminate is sintered, the shrinkage rate of the insulation layer and the shrinkage rate of the coil conductors can be brought as close as possible. As a result, degradation of the electrical properties of the coil caused by the difference in shrinkage rate between the insulation layer and the coil conductors can be further suppressed.

[0114] Preferably, the maximum aperture of each of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor is smaller than the maximum aperture of the coil conductor other than the first coil conductor and the second coil conductor (the third coil conductor).

[0115] By satisfying the above configuration, the risk of disconnection due to voids in the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor can be further suppressed.

[0116] The maximum pore diameter in the coil conductors other than the first and second coil conductors means the diameter of the largest pore among all pores present in the coil conductors other than the first and second coil conductors (third coil conductors).

[0117] Preferably, when the porosity area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor (the third coil conductor) is greater than 11.00% and less than 20.00%, the largest pores in the coil conductors other than the first coil conductor and the second coil conductor exist in the coil conductor having a porosity area ratio greater than 11.00% and less than 20.00%.

[0118] Furthermore, it is preferable that the maximum pore size of each coil conductor having a pore area ratio exceeding 11.00% and not more than 20.00% is larger than the maximum pore size of each of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor.

[0119] The through-hole conductor constituting the first lead conductor is also referred to as the first through-hole conductor, the through-hole conductor constituting the second lead conductor is also referred to as the second through-hole conductor, and the through-hole conductors constituting the internal electrode other than the first and second through-hole conductors are also referred to as the third through-hole conductor.

[0120] The third through-hole conductor may also have a void.

[0121] The void area ratio of the third through-hole conductor is not particularly limited, but is preferably the same as the void area ratio of the third coil conductor. That is, the void area ratio of the third through-hole conductor is preferably greater than 11.00% and less than 20.00%.

[0122] The pore size distribution of the third via-hole conductors is not particularly limited, but is preferably similar to that of the third coil conductor. For example, the maximum pore size of the third via-hole conductors may be the same as that of the third coil conductor.

[0123] Preferably, the maximum pore size of the third coil conductor and the third via-hole conductor having a pore area ratio exceeding 1.00% and not more than 20.00% is larger than the maximum pore size of each of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor.

[0124] It is preferable that the insulating layer include ferrite, and the void area ratio of the insulating layer is 0.10% or more and 5.00% or less.

[0125] When the insulating layer contains ferrite and has a void area ratio of 0.10% to 5.00%, short circuits between coil conductors facing each other through the insulating layer are less likely to occur, even when the insulating layer has a sufficiently high resistance and a large current flows. However, when the void area ratio of the insulating layer exceeds 5.00%, short circuits between coil conductors facing each other through the insulating layer may be more likely to occur.

[0126] However, an insulating layer containing ferrite and having a porosity of 0.10% to 5.00% significantly shrinks during sintering. This shrinkage of the insulating layer during sintering may exert stress on the coil conductor, degrading electrical properties (permeability).

[0127] However, if the porosity of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor exceeds 11.00% and is less than 20.00%, the shrinkage rate of the insulating layer can be made close to the shrinkage rate of the conductor paste that becomes the coil conductor. Therefore, when the insulating layer has ferrite and the porosity is greater than 0.10% and less than 5.00%, the stress applied to the coil conductor can be reduced, thereby suppressing the reduction in electrical properties (magnetic permeability).

[0128] In this specification, "direct connection between a coil conductor and a lead conductor" means that the lead conductor is directly connected to the lead conductor without passing through the winding portion of another coil conductor. Therefore, if the first lead conductor is directly connected to multiple coil conductors without passing through the winding portion of the coil conductor, the first coil conductor has multiple layers. Similarly, if the second lead conductor is directly connected to multiple coil conductors without passing through the winding portion of the coil conductor, the second coil conductor has multiple layers.

[0129] An example of a laminated coil component including two layers of first coil conductors and two layers of second coil conductors will be described as a laminated coil component according to a second embodiment of the present invention.

[0130] Figure 7 It is an exploded perspective view schematically showing an example of a laminated body constituting an example of a laminated coil component according to the second embodiment of the present invention.

[0131] like Figure 7 As shown, the stacked body 60 is constructed by stacking a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in a stacking direction (here, the longitudinal direction L) from the first end face 11 side toward the second end face 12 side of the stacked body 60.

[0132] However, in the second and third insulating layers 31a having a coil conductor, counted from the side closest to the first end face 11, unlike the first insulating layer 31a counted from the first end face 11 side, through-hole conductors 33a are respectively provided directly below both sides of the solder pads 35a provided at both ends of the winding portion 34a.

[0133] Similar to the insulating layer 31a, in the fifth insulating layer 31b counted from the first end face 11 side, unlike the fourth insulating layer 31b counted from the first end face 11 side, through-hole conductors 33b are respectively provided directly below both sides of the solder pads 35b provided at the two end portions of the winding portion 34b.

[0134] Similar to the insulating layer 31a and the insulating layer 31b, in the insulating layer 31d of the eighth layer counted from the first end face 11 side, unlike the insulating layer 31d of the seventh layer counted from the first end face 11 side, a through-hole conductor 33d is respectively provided directly below both sides of the solder pad 35d provided at the two end portions of the winding portion 34d.

[0135] Thus, the coil conductors having winding portions of the same shape (the coil conductors 32 a , the coil conductors 32 b , and the coil conductors 32 d ) are connected in parallel.

[0136] Figure 8 Is perspective Figure 7 1 is a side view schematically showing the state of the voids in the internal electrodes of the laminated coil component of the laminate shown.

[0137] like Figure 8 As shown, the laminated coil component 3 includes a laminate 60 , a first external electrode 21 covering the first end surface 11 of the laminate 60 , and a second external electrode 22 covering the second end surface 12 .

[0138] A first lead conductor 41 , a second lead conductor 42 , and a coil 130 , which serve as internal electrodes, are arranged inside the laminate 60 .

[0139] In the laminate 60, the coil conductors 32a of the first, second, and third layers, as counted from the first end face 11 side, are connected in the stacking direction via the via-hole conductors 33a2 and 33a3. Therefore, it can be said that the coil conductors 32a (132a1, 132a2, 132a3) of the first, second, and third layers, as counted from the first end face 11 side, are all first coil conductors directly connected to the first lead conductor 41. The first coil conductors 132a1, 132a2, and 132a3 are also collectively referred to as first coil conductors 132a.

[0140] Similarly, the coil conductors 32d of the seventh and eighth layers, counted from the first end face 11 side, are connected in the stacking direction through the through-hole conductors 33f. Therefore, it can be said that the coil conductors 132d1 and 132d2 of the seventh and eighth layers, counted from the first end face 11 side, are both second coil conductors directly connected to the second lead conductor 42. The second coil conductors 132d1 and 132d2 are also collectively referred to as second coil conductors 132d. In addition, Figure 8In the figure, the via-hole conductor 33f and the via-hole conductor 33d overlap between the coil conductors 132d1 and 132d2 and are not visible.

[0141] The coil conductors other than the first coil conductor 132a and the second coil conductor 132d are connected to the first lead conductor 41 or the second lead 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 correspond to coil conductors directly connected to the first lead conductor 41 or the second lead conductor 42.

[0142] First coil conductors 132a1, 132a2, and 132a3 having the same shape of winding portion 34a are connected in parallel via via-hole conductor 33a. Similarly, two layers of coil conductors 32b having the same shape of winding portion 34b are connected in parallel via via-hole conductor 33b, and second coil conductors 132d1 and 132d2 having the same shape of winding portion 34d are connected in parallel via via-hole conductor 33d.

[0143] Such a coil is called a parallel multi-wound coil (inductor).

[0144] In addition, when the first coil conductor has multiple layers, the portion of the first coil conductor sandwiched between the through-hole conductors on both sides in the stacking direction is also included in the first lead conductor. Figure 8 In that case, when there are three layers of first coil conductors 132a1, 132a2 and 132a3 directly connected to the first lead-out conductor 41, the through-hole conductor 33a2 connects the first coil conductor 132a1 and the first coil conductor 132a2, and the through-hole conductor 33a3 connects the first coil conductor 132a2 and the first coil conductor 132a3, the portion 132a11 of the first coil conductor 132a1 sandwiched by the through-hole conductor 33a1 and the through-hole conductor 33a2, and the portion 132a21 of the first coil conductor 132a2 sandwiched by the through-hole conductor 33a2 and the through-hole conductor 33a3 serve as the first lead-out conductor 41.

[0145] Similarly, when there are two layers of second coil conductors 132d1 and 132d2 directly connected to the second lead conductor 42, and the through-hole conductor 33d connects the second coil conductor 132d1 and the second coil conductor 132d2, the portion 132d21 of the second coil conductor 132d2 sandwiched by the through-hole conductor 33f and the through-hole conductor 33d constituting the second lead conductor 42 serves as the second lead conductor 42.

[0146] exist Figure 8In the illustrated laminate 60 , the first lead conductor 41 , the second lead conductor 42 , the first coil conductors 132 a 1 , 132 a 2 , and 132 a 3 , and the second coil conductors 132 d 1 and 132 d 2 all have a void area ratio of 1.00% to 11.00%.

[0147] The effect of bubbles generated within the conductor paste during firing being drawn outward is considered to be strongest in the exposed portions of the internal electrodes of the laminate, i.e., the lead conductors, and decreases inward. Therefore, when multiple first coil conductors are present, the risk of wire breakage can be reduced by setting the porosity area ratio of all first coil conductors to between 1.00% and 11.00%. Similarly, when multiple second coil conductors are present, the risk of wire breakage can be reduced by setting the porosity area ratio of all second coil conductors to between 1.00% and 11.00%.

[0148] The present invention is not limited to the method in which the stacking direction of the insulation layer and the direction in which the lead conductor extends are parallel to the mounting surface (horizontally wound laminated coil component), but can also be applied to the method in which the stacking direction of the insulation layer and the direction in which the lead conductor extends are orthogonal to the mounting surface (longitudinal wound laminated coil component).

[0149] An example of a longitudinally wound laminated coil component will be described as a laminated coil component according to a third embodiment of the present invention.

[0150] Figure 9 It is a perspective view schematically showing an example of a laminated coil component according to a third embodiment of the present invention.

[0151] like Figure 9 As shown, the laminated coil component 5 is composed of a laminated body 70 , a first external electrode 21 , and a second external electrode 22 .

[0152] The stack 70 has a first end face 11 and a second end face 12 opposite to each other in the length direction L, a first main face 13 and a second main face 14 opposite to each other in the height direction T perpendicular to the length direction L, and a first side face 15 and a second side face 16 opposite to each other in the width direction W perpendicular to the length direction L and the height direction T.

[0153] The first external electrode 21 is an inclined electrode that covers a portion of the first end surface 11 , extends from the first end surface 11 to cover a portion of the first principal surface 13 serving as the mounting surface, and extends from the first end surface 11 and the first principal surface 13 to cover a portion of the first side surface 15 and the second side surface 16 .

[0154] The second external electrode 22 is an inclined electrode that covers a portion of the second end surface 12 , extends from the second end surface 12 to cover a portion of the first principal surface 13 serving as the mounting surface, and extends from the second end surface 12 and the first principal surface 13 to cover a portion of the first side surface 15 and the second side surface 16 .

[0155] In addition, the shapes of the first external electrode and the second external electrode are not limited to the above-mentioned inclined electrodes, and may also be Figures 1 to 5 The laminated coil component 1 shown, Figure 7 The shape is the same as that of the laminated coil component 3 shown in FIG. 8 .

[0156] Figure 10 It schematically represents the composition Figure 9 1 is an exploded perspective view of an example of a laminated body of the laminated coil component shown.

[0157] like Figure 10 As shown, the stacked body 70 is formed 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 stacked body 70. Hereinafter, the insulating layers 131a, 131b, 131c, 131d, 131g, 131h, and 131i are also collectively referred to as insulating layers 131.

[0158] Coil conductors 32a, 32b, 32c, and 32d, via-hole conductors 33a, 33b, 33c, and 33d, pads 35f, and via-hole conductors 33f are provided on insulating layers 131a, 131b, 131c, and 131d, respectively.

[0159] The coil conductors 32a, 32b, 32c, and 32d each include an annular winding portion 34a, 34b, 34c, and 34d, each having a partially missing portion and a gap, and pads 35a, 35b, 35c, and 35d. The pads 35a, 35b, 35c, and 35d are provided at both ends of the winding portions 34a, 34b, 34c, and 34d, respectively.

[0160] The pad 35f and the via-hole conductor 33f are provided separately from the coil conductors 32a, 32b, 32c, and 32d.

[0161] The insulating layer 131h includes a coil conductor 132b and a via-hole conductor 33b. The coil conductor 132b includes a winding portion 134b partially overlapping the winding portion 34b of the coil conductor 32b, and pads 35b provided at both ends of the winding portion 134b.

[0162] Insulating layer ( 131g ) is provided with pads ( 35e , 35f ) and via-hole conductors ( 33e , 33f ).

[0163] The insulating layer 131g may be a single layer or two or more layers.

[0164] Insulating layer 131i does not include any coil conductors, pads, or via conductors.

[0165] The insulating layer 131i may be one layer or two or more layers.

[0166] Figure 11 It is schematically represented Figure 9 1 is a cross-sectional view of an example of a cross section of the laminated coil component taken along line segment A3 - A3 .

[0167] like Figure 11 As shown, a first lead conductor 41 , a second lead conductor 42 , and a coil 230 serving as internal electrodes are arranged inside the laminate 70 .

[0168] The coil conductors 132 a , 32 b , 32 c , 32 d , 32 a , and 132 b are electrically connected in the stacking direction by the via-hole conductors 33 a , 33 b , 33 c , and 33 d , thereby forming the coil 230 .

[0169] Via conductors 33a and 33e and pads 35e formed in insulating layer 131a adjacent to insulating layer 131g serve as first lead conductors 41 in laminate 70 and are exposed on the first end surface 11 side of first principal surface 13 of laminate 70 .

[0170] Of the two pads 35b formed on the insulating layer 131h, the pad 35b arranged at a position that does not overlap with the winding shape of the coil, the through-hole conductor 33b arranged directly below the pad 35b, the through-hole conductor 33f, and the pad 35f become the second lead-out conductor 42 in the stack 70, and are exposed on the second end face 12 side of the first main surface 13 of the stack 70.

[0171] The direction in which the first lead conductor 41 and the second lead conductor 42 extend is parallel to the stacking direction of the insulating layers and is perpendicular to the first main surface 13 serving as the mounting surface.

[0172] Furthermore, the first lead conductor 41 and the second lead conductor 42 are exposed on the same surface (first main surface 13 ) of the laminate 70 .

[0173] Among the coil conductors, the coil conductor 32 a directly connected to the first lead conductor 41 is a first coil conductor 132 a .

[0174] Among the coil conductors, the coil conductor 132 b directly connected to the second lead conductor 42 serves as a second coil conductor.

[0175] Therefore, the laminated body 70 has one layer of the first coil conductor 132a and one layer of the second coil conductor 132b. Among the coil conductors, the coil conductors other than the first coil conductor 132a and the second coil conductor 132b are also referred to as third coil conductors.

[0176] like Figure 11 As shown, apertures 50 are formed in the through-hole conductors 33a and 33e and the pad 35e that constitute the first lead conductor 41, and in the through-hole conductors 33b and 33f and the pads 35b and 35f that constitute the second lead conductor 42. Furthermore, apertures 50 are formed in the coil conductors 32a, 32b, 32c, and 32d (third coil conductors) other than the first coil conductor 132a and the second coil conductor 132b, and in the through-hole conductors 33a, 33b, 33c, and 33d that connect the third coil conductors.

[0177] exist Figure 11 In the illustrated laminated body 70 , the first lead conductor 41 , the second lead conductor 42 , the first coil conductor 132 a , and the second coil conductor 132 b each have a void area ratio of 1.00% to 11.00%.

[0178] When the conductor paste is fired, the voids generated in and around the lead conductors are drawn out regardless of whether the stacking direction of the coil conductors is parallel to or perpendicular to the mounting surface. Therefore, even in a longitudinally wound laminated coil component, as long as the void 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 void 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. Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 as well as Figure 5 The laminated coil component 1 , which is a transversely wound laminated coil component shown, can also reduce the risk of disconnection of the lead-out connection portion.

[0179] [Method for Manufacturing Laminated Coil Component]

[0180] In a method for manufacturing a stacked coil component according to a first embodiment of the present invention, the stacked coil component comprises: a stacked body formed by stacking 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 comprising: 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 extending in the stacking direction of the insulating layer, and is characterized in that the method for manufacturing a stacked coil component comprises the following steps: a step of preparing a ceramic green sheet comprising a ceramic material; a step of stacking a plurality of ceramic green sheets ... A step of printing a conductor paste on the ceramic green sheet to form a conductor paste layer which becomes the coil conductor, the first lead conductor and / or the second lead conductor; a step of producing an unfired laminated body in which a plurality of the ceramic green sheets having the conductor paste layer formed thereon are stacked and an unfired coil is built in; and a step of firing the unfired laminated body to produce a laminated body, wherein when the coil conductor directly connected to the first lead conductor among the coil conductors is set as the first coil conductor and the coil conductor directly connected to the second lead conductor is set as the second coil conductor, the PVC of the conductor paste used for the first coil conductor, the second coil conductor, the first lead conductor and the second lead conductor is greater than 45.00% and less than 55.00%.

[0181] An example of a method for manufacturing a laminated coil component according to the present invention will be described below.

[0182] <Magnetic Material Production Process>

[0183] First, Fe 2 O 3 , ZnO, CuO, and NiO are weighed so as to achieve a predetermined ratio.

[0184] Next, these weighed materials, pure water, and PSZ (partially stabilized zirconia) media are placed in a ball mill, mixed, and then pulverized. The mixing and pulverization time is, for example, 4 hours to 8 hours.

[0185] The obtained pulverized product is dried and then calcined. The calcination temperature is, for example, 700° C. to 800° C., and the calcination time is, for example, 2 hours to 5 hours.

[0186] In this way, a powdery magnetic material, more specifically, a powdery magnetic ferrite material is produced.

[0187] The ferrite material is preferably a Ni—Cu—Zn ferrite material.

[0188] Regarding Ni-Cu-Zn ferrite materials, when the total amount is set to 100 mol%, it is preferred that when converted to Fe2O3, it contains 40 mol% or more and 49.5 mol% or less of Fe, when converted to ZnO, it contains 2 mol% or more and 35 mol% or less of Zn, when converted to CuO, it contains 6 mol% or more and 13 mol% or less of Cu, and it contains 10 mol% or more and 45 mol% or less of Ni when converted to NiO.

[0189] The Ni—Cu—Zn-based ferrite material may further contain additives such as Co, Bi, Sn, and Mn.

[0190] The Ni—Cu—Zn-based ferrite material may further contain unavoidable impurities.

[0191] Green Sheet Production Process

[0192] First, a magnetic material, an organic binder such as a polyvinyl butyral resin, an organic solvent such as ethanol or toluene, and a plasticizer are placed in a ball mill together with a PSZ medium, mixed, and then pulverized to prepare a slurry.

[0193] 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 to 30 μm inclusive. The shape of the green sheet is, for example, rectangular.

[0194] As the material of the green sheet, a non-magnetic material such as a borosilicate glass material may be used instead of a magnetic material, or a mixed material of a magnetic material and a non-magnetic material may be used.

[0195] <Conductor Pattern Formation Process>

[0196] First, through holes are formed by irradiating predetermined portions of a green sheet with laser light.

[0197] Next, a conductor paste containing a conductive material, a resin component, and a solvent is filled into the through hole and applied to the surface of the raw sheet by screen printing or the like. Thus, a conductor pattern for a through-hole conductor is formed in the through hole of the raw sheet, and a conductor pattern for a coil conductor and / or a conductor pattern for a pad connected to the conductor pattern for the through-hole conductor is formed on the surface. In this way, a coil sheet having a conductor pattern for a coil conductor and / or a conductor pattern for a pad and a conductor pattern for a through-hole conductor formed on the raw sheet is produced. Figure 2 The coil conductor 32 shown in FIG. Figure 2 The through-hole conductor 33 (excluding the through-hole conductors 33e and 33f) shown in FIG. Figure 2 The via-hole conductors 33e and 33f shown are formed using a via sheet having a conductor pattern.

[0198] In the manufacturing method of the stacked coil component of the first embodiment of the present invention, at this time, the PVC of the conductor paste for the first lead conductor (a conductor paste for forming a conductor pattern for a pad to become the first lead conductor and a conductor pattern for a through-hole conductor), the conductor paste for the second lead conductor (a conductor paste for forming a conductor pattern for a pad to become the second lead conductor and a conductor pattern for a through-hole conductor), the conductor paste for the first coil conductor (a conductor paste for forming a conductor pattern for a coil conductor to become the first coil conductor), and the conductor paste for the second coil conductor (a conductor paste for forming a conductor pattern for a coil conductor to become the second coil conductor) are set to be greater than 45.00% and less than 55.00%, respectively.

[0199] By setting the PVC of the conductor paste used for the first coil conductor, the second coil conductor, the first lead conductor and the second lead conductor to be greater than 45.00% and less than 55.00%, the porosity area ratios of the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor can be set to be greater than 1.00% and less than 11.00%, respectively, thereby obtaining the stacked coil component of the present invention.

[0200] Furthermore, PVC refers to the concentration (Pigment Volume Concentration) of the volume of the conductive material relative to the total volume of the conductive material (typically metal powder) and the resin component in the conductor paste.

[0201] PVC indicates the volume ratio of non-resin components in a conductor paste. Therefore, a conductor formed using a conductor paste having a relatively high PVC content has a smaller void area ratio than a conductor formed using a conductor paste having a relatively low PVC content.

[0202] Examples of the conductive material include metal powders composed of Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals. Among these, Ag powder is preferred.

[0203] Examples of the resin component include ethyl cellulose and the like.

[0204] 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-porosity conductor paste.

[0205] In the method for manufacturing a laminated coil component according to the first embodiment of the present invention, the low-porosity conductor paste is a conductor paste having a PVC content of 45.00% to 55.00%.

[0206] As the conductor paste for coil conductors other than the first and second coil conductors, the above-mentioned low-porosity conductor paste may be used, but it is preferable to use a conductor paste having a PVC of 30.00% to 40.00% for at least one layer.

[0207] That is, it is preferable that 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.

[0208] If the PVC of the conductor paste used for at least one layer of coil conductors other than the first coil conductor and the second coil conductor is greater than 30.00% and less than 40.00%, the porosity area ratio of at least one layer of coil conductors other than the first coil conductor and the second coil conductor can be made greater than 11.00% and less than 20.00%.

[0209] If the porosity area ratio of at least one layer of the coil conductors other than the first and second coil conductors exceeds 11.00% and is no greater than 20.00%, the shrinkage rate of the insulating layer can be made close to that of the coil conductors during sintering of the laminate. Consequently, degradation of the electrical properties of the coil caused by the difference in shrinkage rate between the insulating layer and the coil conductors can be suppressed.

[0210] When the number of layers of all coil conductors other than the first and second coil conductors is set to 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.

[0211] If the PVC of the conductor paste used for the coil conductors comprising at least 50% of the total number of coil conductor layers other than the first and second coil conductors is 30.00% or higher and 40.00% or lower, the porosity area ratio of at least 50% of the coil conductors other than the first and second coil conductors can be kept above 11.00% and below 20.00%. This allows the shrinkage rate of the insulation layer to be more closely aligned with that of the coil conductors during sintering of the laminate. Consequently, degradation of the electrical properties of the coil caused by the difference in shrinkage rate between the insulation layer and the coil conductors can be further suppressed.

[0212] The PVC of the conductor paste for all coil conductors other than the first coil conductor and the second coil conductor is more preferably 30.00% or more and 40.00% or less.

[0213] If the PVC of the conductor paste for all coil conductors other than the first and second coil conductors is 30.00% to 40.00%, the void area ratio of all coil conductors other than the first and second coil conductors can be made greater than 11.00% and less than 20.00%.

[0214] If the porosity area ratio of all coil conductors other than the first and second coil conductors exceeds 11.00% and is less than 20.00%, all coil conductors other than the first and second coil conductors are composed of coil conductors with a large shrinkage rate during sintering. Therefore, when the laminate is sintered, the shrinkage rate of the insulation layer and the shrinkage rate of the coil conductors can be brought as close as possible. As a result, degradation of the electrical properties of the coil caused by the difference in shrinkage rate between the insulation layer and the coil conductor can be further suppressed.

[0215] In this specification, a conductor paste for forming a coil conductor layer having a void area ratio exceeding 11.00% and not more than 20.00% is also referred to as a high-void conductor paste.

[0216] In the method for manufacturing a laminated coil component according to the first embodiment of the present invention, the high-porosity conductor paste is a conductor paste having a PVC content of 30.00% to 40.00%.

[0217] That is, in the manufacturing method of the stacked coil component of the first embodiment of the present invention, it is preferred to use a low-porosity conductor paste to form the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor, and thereafter, a high-porosity conductor paste is used to further form at least one layer of the coil conductor (third coil conductor) other than the first coil conductor and the second coil conductor. When the number of layers of all third coil conductors is set to 100%, it is more preferred to use a high-porosity conductor paste to form more than 50% of the layers of the third coil conductor, and it is more preferred to use all high-porosity conductor pastes used to form the third coil conductors.

[0218] The high-porosity conductor paste described above can also be used as a conductor paste for forming through-hole conductor patterns other than the through-hole conductor patterns serving as first lead conductors and the through-hole conductor patterns serving as second lead conductors.

[0219] In this case, the void area ratio of the through-hole conductors other than the first through-hole conductor and the second through-hole conductor (the third through-hole conductor) can be set to more than 11.00% and not more than 20.00%.

[0220] The maximum pore size in a conductor formed using a low-porosity conductor paste is likely to be smaller than the maximum pore size in a conductor formed using a high-porosity conductor paste. Therefore, by using a conductor paste with a PVC of 45.00% or more and 55.00% or less (low-porosity conductor paste) as the conductor paste for the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor, and using a conductor paste with a PVC of 30.00% or more and 40.00% or less (high-porosity conductor paste) as the conductor paste for at least one layer of coil conductors other than the first and second coil conductors, the maximum pore size of each of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor can be made smaller than the maximum pore size of the coil conductor other than the first and second coil conductors (the third coil conductor).

[0221] <Laminated Block Production Process>

[0222] Place the coil sheet and the through-hole sheet in the same Figure 2 After stacking in the stacking direction (longitudinal direction L) in the order of , they are thermocompression-bonded to produce a stacked body block.

[0223] <Laminate and Coil Manufacturing Process>

[0224] First, the laminated body block is cut into predetermined sizes using a dicing machine or the like, thereby producing individual chips.

[0225] Next, the singulated chips are fired at a temperature of, for example, 900° C. to 920° C., and for a time of, for example, 2 hours to 4 hours.

[0226] When the individual chips are fired, the green sheets of the coil sheet and the through-hole sheet serve as insulating layers.

[0227] Furthermore, when the singulated chips are fired, the coil conductor pattern, pad conductor pattern, and via conductor pattern become coil conductors, pads, and via conductors, respectively. This results in a coil electrically connecting multiple coil conductors stacked together with the insulating layer via the via conductors, and a first lead conductor and a second lead conductor extending the coil to the end surface of the stacked body.

[0228] At this time, voids are generated in the coil conductor, the pad, and the via-hole conductor at an area ratio corresponding to the composition of the original conductor pattern (conductor paste).

[0229] As described above, a laminated body is produced in which a plurality of insulating layers are laminated in the lamination direction and the coil is built therein.

[0230] The laminate may be subjected to barrel polishing, for example, to round corners and ridges.

[0231] External Electrode Formation Process

[0232] First, a conductive paste, such as a paste containing Ag and glass frit, is applied to the first and second end faces of the lead coils on the outer surface of the laminate to form a conductive paste layer.

[0233] Next, the conductive paste layer is fired to form a base electrode of the external electrode. The firing temperature is, for example, 800° C. to 820° C. The thickness of the base electrode is, for example, 5 μm.

[0234] Then, a Ni-plated electrode and a Sn-plated electrode are sequentially formed on the surface of the base electrode by electroplating, etc. Thus, an external electrode including the base electrode, the Ni-plated electrode, and the Sn-plated electrode in this order is formed.

[0235] Based on the above, a laminated coil component is manufactured.

[0236] In the manufacturing method of the stacked coil component of the second embodiment of the present invention, the stacked coil component comprises: a stacked body formed by stacking a plurality of insulating layers and having an internal electrode; and a first external electrode and a second external electrode electrically connected to the above-mentioned internal electrode, the above-mentioned internal electrode comprising: a coil formed by electrically connecting a plurality of coil conductors stacked together with the above-mentioned insulating layer; a first lead-out conductor connecting the above-mentioned coil and the above-mentioned first external electrode; and a second lead-out conductor connecting the above-mentioned coil and the above-mentioned second external electrode, the above-mentioned first lead-out conductor and the above-mentioned second lead-out conductor extending in the stacking direction of the above-mentioned insulating layer, and is characterized in that the manufacturing method of the stacked coil component comprises the following steps: a step of preparing ceramic green sheets containing ceramic material; a step of printing a conductor paste on the plurality of the above-mentioned ceramic green sheets to form the above-mentioned coil conductor, A step of printing the conductor paste layer of the first lead conductor and / or the second lead conductor; a step of making an unfired laminated body in which a plurality of the ceramic green sheets formed with the conductor paste layer are stacked and an unfired coil is built in; and a step of firing the unfired laminated body to make the laminated body, wherein when the coil conductor directly connected to the first lead conductor among the coil conductors is set as the first coil conductor, and the coil conductor directly connected to the second lead conductor is set as the second coil conductor, the conductor paste used for the first coil conductor, the second coil conductor, the first lead conductor and the second lead conductor contains metal powder manufactured by a method other than the water atomization method, and the conductor paste used for at least one layer of the coil conductors other than the first coil conductor and the second coil conductor contains metal powder manufactured by the water atomization method.

[0237] Water atomization is a method of forming metal powder by spraying or colliding water onto molten metal. Since the molten metal comes into contact with the water, oxygen is readily available within the metal powder. Therefore, when a conductor paste containing metal powder produced using water atomization is fired, more pores are formed within the fired conductor compared to when a conductor paste containing metal powder produced using methods other than water atomization is fired. Furthermore, the term "methods other than water atomization" encompasses both methods other than atomization and methods other than water atomization.

[0238] Based on the above reasons, the conductor paste for the first coil conductor, the second coil conductor, the first lead conductor and the second lead conductor contains metal powder manufactured by a method other than the water atomization method, and the conductor paste for at least one layer of the above-mentioned coil conductor other than the above-mentioned first coil conductor and the above-mentioned second coil conductor contains metal powder manufactured by the water atomization method, thereby obtaining the following stacked coil component, wherein the porosity area ratios of the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor are respectively greater than 1.00% and less than 11.00%, and the porosity area ratio of at least one layer of the coil conductor other than the first coil conductor and the second coil conductor exceeds 11.00% and is less than 20.00%.

[0239] It can be said that in the manufacturing method of the stacked coil component of the second embodiment of the present invention, the low-porosity conductor paste in the manufacturing method of the stacked coil component of the first embodiment of the present invention is changed from "conductor paste having a PVC of 45.00% or more and 55.00% or less" to "conductor paste containing metal powder manufactured by a method other than the water atomization method", and the high-porosity conductor paste is specifically defined as "conductor paste containing metal powder manufactured by the water atomization method".

[0240] Therefore, in the method for manufacturing a laminated coil component according to the second embodiment of the present invention, the high-porosity conductor paste is a conductor paste containing metal powder produced by water atomization, and the low-porosity conductor paste is a conductor paste containing metal powder produced by a method other than water atomization.

[0241] Examples of the metal powder produced by the water atomization method include metal powders composed of Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals. Among these, Ag powder is preferred.

[0242] Examples of methods for producing metal powders other than the water atomization method include electrolysis, crushing, chemical reduction, heat treatment, and atomization methods such as gas atomization, disk atomization, and plasma atomization.

[0243] Examples of metal powders produced by methods other than the water atomization method include metal powders composed of Ag, Au, Cu, Pd, Ni, Al, and alloys containing at least one of these metals. Among these, Ag powder is preferred.

[0244] The metal powder produced by the water atomization method and the metal powder produced by a method other than the water atomization method may be of different types (compositions), but are preferably the same.

[0245] For example, when the metal powder produced by the water atomization method is Ag powder, the metal powder produced by a method other than the water atomization method is also preferably Ag powder.

[0246] The following matters are described in this manual.

[0247] The present disclosure (1) provides a laminated coil component, characterized by comprising: a laminated body 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.

[0248] 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.

[0249] The first lead conductor and the second lead conductor extend in the stacking direction of the insulating layer.

[0250] In the above-mentioned coil conductors, when the coil conductor directly connected to the first lead conductor is referred to as the first coil conductor and the coil conductor directly connected to the second lead conductor is referred to as the second coil conductor,

[0251] Each of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor has a void area ratio of 1.00% or more and 11.00% or less.

[0252] In the present disclosure (2), according to the laminated coil component described in the present disclosure (1), the porosity area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor exceeds 11.00% and is 20.00% or less.

[0253] In the present disclosure (3), according to the laminated coil component described in the present disclosure (2), the void area ratio of all the coil conductors other than the first coil conductor and the second coil conductor exceeds 11.00% and is 20.00% or less.

[0254] In the present disclosure (4), according to a stacked coil component of any combination with any one of the present disclosures (1) to (3), the thickness of the first coil conductor is larger than the maximum aperture in the first coil conductor, and the thickness of the second coil conductor is larger than the maximum aperture in the second coil conductor.

[0255] In the present disclosure (5), according to the stacked coil component of any combination with any one of the present disclosures (1) to (4), the maximum aperture of each of the first lead conductor, the second lead conductor, the first coil conductor and the second coil conductor is smaller than the maximum aperture of the coil conductors other than the first coil conductor and the second coil conductor.

[0256] In the present disclosure (6), according to the laminated coil component in any combination with any one of the present disclosures (1) to (5), the insulating layer includes ferrite, and the void area ratio of the insulating layer is 0.10% or more and 5.00% or less.

[0257] In the present disclosure (7), according to the stacked coil component of any combination with any one of the present disclosures (1) to (5), the porosity area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor are respectively greater than 1.00% and less than 4.00%.

[0258] The present disclosure (8) provides a method for manufacturing a laminated coil component, the laminated coil component comprising: a laminated body 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.

[0259] 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.

[0260] The first lead conductor and the second lead conductor extend in the stacking direction of the insulating layer. The method for manufacturing the laminated coil component includes the following steps:

[0261] A step of preparing a ceramic green sheet containing a ceramic material;

[0262] a step of printing a conductor paste on the plurality of ceramic green sheets to form a conductor paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor;

[0263] a step of producing an unfired laminated body comprising a plurality of the ceramic green sheets on which the conductor paste layer is formed and in which an unfired coil is built; and

[0264] The process of firing the unfired laminate to produce the laminate,

[0265] In the above-mentioned coil conductors, when the coil conductor directly connected to the first lead conductor is referred to as the first coil conductor and the coil conductor directly connected to the second lead conductor is referred to as the second coil conductor,

[0266] 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.

[0267] In the present disclosure (9), according to the manufacturing method of the stacked coil component described in the present disclosure (8), the PVC of the conductor paste used for at least one layer of the above-mentioned first coil conductor and the above-mentioned coil conductor other than the above-mentioned second coil conductor is greater than 30.00% and less than 40.00%.

[0268] In the present disclosure (10), according to the method for manufacturing a laminated coil component described in the present disclosure (9), the PVC of the conductor paste used for all the coil conductors except the first coil conductor and the second coil conductor is greater than or equal to 30.00% and less than or equal to 40.00%.

[0269] The present disclosure (11) provides a method for manufacturing a laminated coil component, the laminated coil component comprising: a laminated body 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.

[0270] 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.

[0271] The first lead conductor and the second lead conductor extend in the stacking direction of the insulating layer. The method for manufacturing the laminated coil component includes the following steps:

[0272] A step of preparing a ceramic green sheet containing a ceramic material;

[0273] a step of printing a conductor paste on the plurality of ceramic green sheets to form a conductor paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor;

[0274] a step of producing an unfired laminated body comprising a plurality of the ceramic green sheets on which the conductor paste layer is formed and in which an unfired coil is built; and

[0275] The process of firing the unfired laminate to produce the laminate,

[0276] In the above-mentioned coil conductors, when the coil conductor directly connected to the first lead conductor is referred to as the first coil conductor and the coil conductor directly connected to the second lead conductor is referred to as the second coil conductor,

[0277] 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.

[0278] 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.

[0279] [Example]

[0280] Hereinafter, examples will be shown that more specifically disclose the present invention, but the present invention is not limited to these examples.

[0281] (Preparation of Samples 1 to 6)

[0282] According to the method for manufacturing a laminated coil component according to the first embodiment of the present invention, as shown in Table 1 below, 100 samples 1 to 6 (laminated coil components) were manufactured, each using different compositions (PVC) of the conductor pastes for the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor (low-porosity conductor paste), and the conductor paste for the coil conductor other than the first and second coil conductors (third coil conductor) (high-porosity conductor paste). Table 1 shows the PVC of the low-porosity conductor paste and the high-porosity conductor paste used to manufacture each sample.

[0283] (Determination of the presence or absence of disconnection)

[0284] For each sample, all 100 electrical characteristics (DC resistance) were measured, and the presence or absence of disconnection was determined based on the measurement results. The number of disconnected samples was counted. The results are shown in Table 1.

[0285] (Determination of Porosity and Maximum Pore Diameter)

[0286] Based on the SEM images of the cross sections of each sample, the porosity area ratio and maximum pore diameter of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor were determined, as well as the average porosity area ratio and maximum pore diameter of all coil conductors other than the first and second coil conductors. The average values ​​of 100 samples were calculated. The results are shown in Table 1.

[0287] [Table 1]

[0288] [Table 1]

[0289]

[0290] As shown in Table 1, the aperture area ratios of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor were the same across all samples. Similarly, the maximum aperture diameters of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor were the same across all samples.

[0291] 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 void area ratio of the obtained conductor was 1.00% or more and 11.00% or less.

[0292] Likewise, it was confirmed that by setting the PVC of the conductor paste to 30.00% or more and 40.00% or less, the void area ratio of the obtained conductor exceeded 11.00% and was 20.00% or less.

[0293] It was confirmed that no samples with broken wires occurred in samples 1 to 4, in which the void area ratio of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor was greater than 1.00% and less than 11.00%. On the other hand, in samples 5 and 6, in which the void area ratio of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor exceeded 11.00%, broken wires occurred near the connection (bend) between the first lead conductor and the coil conductor, and / or near the connection (bend) between the second lead conductor and the coil conductor. Furthermore, in samples 5 and 6, in which broken wires occurred, voids were concentrated at the connection between the first lead conductor and the first coil conductor, or at the connection between the second lead conductor and the second coil conductor.

[0294] From the above results, it was confirmed that the laminated coil component of the present invention can reduce the risk of disconnection of the lead-out connection portion.

[0295] In addition, for sample 1 in which the pore area ratio of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor is less than 4.00%, since the maximum pore diameter is approximately 3.3 μm, it is considered that not only the risk of wire breakage is reduced, but also current concentration is suppressed, and conduction can be reliably ensured.

Claims

1. A laminated coil component, characterized in that: The invention comprises: a laminated body 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 the stacking direction of the insulating layer. When the coil conductor directly connected to the first lead conductor is a first coil conductor and the coil conductor directly connected to the second lead conductor is a second coil conductor, The first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor each have a void area ratio of 1.00% to 11.00%.

2. The laminated coil component according to claim 1, wherein The void area ratio of at least one layer of the coil conductors other than the first coil conductor and the second coil conductor exceeds 11.00% and is 20.00% or less.

3. The laminated coil component according to claim 2, wherein: The void area ratio of all the coil conductors other than the first coil conductor and the second coil conductor exceeds 11.00% and is 20.00% or less.

4. The laminated coil component according to claim 1 or 2, wherein: The thickness of the first coil conductor is larger than the maximum aperture in the first coil conductor, The thickness of the second coil conductor is larger than the maximum aperture of the second coil conductor.

5. The laminated coil component according to claim 1 or 2, wherein: The maximum aperture of each of the first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor is smaller than the maximum aperture of the coil conductors other than the first coil conductor and the second coil conductor.

6. The laminated coil component according to claim 1 or 2, wherein: The insulating layer has ferrite, The insulating layer has a void area ratio of 0.10% to 5.00%.

7. The laminated coil component according to claim 1 or 2, wherein: The first lead conductor, the second lead conductor, the first coil conductor, and the second coil conductor each have a void area ratio of 1.00% to 4.00%.

8. A method for manufacturing a laminated coil component, the laminated coil component comprising: 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 the stacking direction of the insulating layer, and are characterized in that: The manufacturing method comprises the following steps: A step of preparing a ceramic green sheet containing a ceramic material; a step of printing a conductor paste on the plurality of ceramic green sheets to form a conductor paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor; a step of producing an unfired laminated body comprising a plurality of the ceramic green sheets on which the conductor paste layer is formed and in which an unfired coil is built; and a step of firing the unfired laminate to produce a laminate, When the coil conductor directly connected to the first lead conductor is a first coil conductor and the coil conductor directly connected to the second lead conductor is a second coil conductor, 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.

9. The method for manufacturing a laminated coil component according to claim 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.

10. The method for manufacturing a laminated coil component according to claim 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.

11. A method for manufacturing a laminated coil component, the laminated coil component comprising: 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 the stacking direction of the insulating layer, and are characterized in that: The manufacturing method comprises the following steps: A step of preparing a ceramic green sheet containing a ceramic material; a step of printing a conductor paste on the plurality of ceramic green sheets to form a conductor paste layer that will become the coil conductor, the first lead conductor, and / or the second lead conductor; a step of producing an unfired laminated body comprising a plurality of the ceramic green sheets on which the conductor paste layer is formed and in which an unfired coil is built; and a step of firing the unfired laminate to produce a laminate, When the coil conductor directly connected to the first lead conductor is a first coil conductor and the coil conductor directly connected to the second lead conductor is 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. 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.

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