JP2019165222A - Wiring circuit board and manufacturing method thereof - Google Patents

Abstract

To provide a wiring circuit board having a high inductance and a manufacturing method thereof while ensuring the insulation of a particle-containing layer with respect to a wiring.SOLUTION: A magnetic wiring circuit board 1 includes a first insulating layer 2, a wiring portion 3, a second insulating layer 4, and a magnetic layer 5 including conductive particles each having a shape with an aspect ratio of 2 or more and covering the wiring portion 3 through the second insulating layer 4. The wiring portion 3 has a substantially curved shape.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printed circuit board and a method for manufacturing the same.

  Conventionally, it is known that a coil module is used for wireless communication or wireless power transmission for transmitting power wirelessly.

  For example, a coil module is proposed that includes a coil pattern and a magnetic layer that embeds the coil pattern and contains flat magnetic particles (conductive particles) (see, for example, Patent Document 1).

  Such a coil module is obtained, for example, by first forming a coil pattern by conductor patterning and then hot pressing a magnetic sheet containing magnetic particles against the coil pattern.

JP 2017-005115 A

  However, there is a case where a large current flows through the coil pattern. In that case, the flat magnetic particles contained in the insulating layer may short-circuit the coil patterns. Insulation is required.

  Therefore, it is tentative to form an insulating layer between the coil pattern and the magnetic layer.

  However, since the ridgeline portions on the upper surface and side surface of the coil pattern are formed with a sharp pointed portion toward the upper oblique side (outside), in this case, if an insulating layer is formed, the sharpened portion is opposed to the sharpened portion. The thickness of the insulating layer is likely to be excessively thin. Therefore, if a magnetic sheet containing magnetic particles is hot-pressed with respect to a coil pattern including a sharpened portion via an insulating layer, the magnetic particles penetrate the insulating layer facing the sharpened portion and become sharpened. As a result, there is a problem that the insulation between the magnetic layer and the coil pattern cannot be ensured by such contact.

  On the other hand, the coil module is also required to have high inductance.

  The present invention provides a printed circuit board having a high inductance and a method for manufacturing the same, while ensuring insulation of the particle-containing layer with respect to the wiring.

  In the present invention (1), the first insulating layer, the wiring disposed on one surface in the thickness direction of the first insulating layer, the second insulating layer covering the wiring, and the shape having an aspect ratio of 2 or more A printed circuit board including a conductive particle having conductive particles, a particle-containing layer covering the wiring via the second insulating layer, and the wiring having a substantially curved shape.

  In this wired circuit board, since the wiring has a substantially curved shape, the second insulating layer covering the portion corresponding to the substantially curved shape in the wiring can be formed while suppressing an excessively thinning. Therefore, it can suppress that electroconductive particle penetrates a 2nd insulating layer and contacts wiring. As a result, the insulating properties of the particle-containing layer with respect to the wiring can be ensured by the second insulating layer.

  Therefore, this printed circuit board can ensure the insulation of the second insulating layer.

  The present invention (2) includes the wired circuit board according to (1), wherein the conductive particles are magnetic particles, the particle-containing layer is a magnetic layer, and is a magnetic wired circuit board.

  In a printed circuit board that is a magnetic wired circuit board, in a magnetic layer that covers a portion corresponding to a substantially curved shape in the wiring via the second insulating layer, magnetic particles having an aspect ratio of 2 or more are formed in the curved shape of the wiring. Can be oriented along. That is, the magnetic particles can be oriented in a direction inclined with respect to the thickness direction and the orthogonal direction in the magnetic layer facing the portion corresponding to the substantially curved shape in the wiring. Therefore, a smooth magnetic path can be formed along the portion corresponding to the substantially curved shape of the wiring in the magnetic layer. Therefore, the effective magnetic permeability around the wiring can be improved. As a result, the printed circuit board has a high inductance.

  Therefore, this printed circuit board can ensure the insulation of the second insulating layer while having a high inductance.

  The present invention (3) includes the printed circuit board according to (2), wherein the second insulating layer is an electrodeposition layer.

  In this wired circuit board, since the second insulating layer is an electrodeposition layer, the thickness of the second insulating layer can be reduced. Therefore, it is possible to suppress a decrease in effective magnetic permeability of the magnetic layer that covers the wiring via the second insulating layer. As a result, this printed circuit board has a high inductance.

  On the other hand, when the thickness of the second insulating layer is thin, the magnetic particles easily penetrate the thin second insulating layer and come into contact with the wiring. However, in this printed circuit board, since the second insulating layer covering the wiring having a substantially curved shape is suppressed from being formed with an excessively thin thickness, the penetration of the second insulating layer by the magnetic particles is suppressed. Thus, the insulation of the second insulating layer can be secured.

  The present invention (4) includes the printed circuit board according to (2) or (3), wherein an average thickness T of the second insulating layer is 10 μm or less.

  In this wired circuit board, since the average thickness T of the second insulating layer is as thin as 10 μm or less, it is possible to suppress a decrease in the effective magnetic permeability of the magnetic layer. As a result, this printed circuit board has a high inductance.

  In the present invention (5), the wiring is in contact with one surface in the thickness direction of the first insulating layer facing the one surface in the thickness direction with a space therebetween, and one surface in the thickness direction of the first insulating layer. The other side in the thickness direction, and one side surface connecting the both ends of the one side in the thickness direction and the other side in the thickness direction, and the second insulating layer covers the one side in the thickness direction and the side surface. The wiring according to any one of (2) to (4), wherein the wiring has a corner formed by the one surface in the thickness direction and the side surface, and the corner has a substantially curved shape. Includes circuit board.

  In this wired circuit board, since the corners of the wiring have a substantially curved shape, the second insulating layer covering the corners can be formed while suppressing an excessive thinning. Therefore, it can suppress that electroconductive particle penetrates a 2nd insulating layer and contacts the corner | angular part of wiring. As a result, the insulating properties of the particle-containing layer with respect to the wiring can be ensured by the second insulating layer. Therefore, this printed circuit board can ensure the insulation of the second insulating layer.

  The present invention (6) includes the printed circuit board according to (5), wherein a radius of curvature R of the corner portion is 9 μm or more.

  In this printed circuit board, when the radius of curvature R of the corner is as large as 9 μm or more, the arc surface of the corner is gentle, and therefore the second insulating layer corresponding to the corner can be formed with a sufficient thickness. it can. In the second magnetic layer facing the corner, the magnetic particles can be reliably oriented along the arc surface of the corner.

  In the present invention (7), the magnetic layer covers the one surface in the thickness direction exposed from the second insulating layer in the first insulating layer, and the wiring is formed by the other surface in the thickness direction and the side surface. (5) or (6) having a second corner portion to be formed, wherein the second corner portion has a portion in which the length between the two side surfaces facing each other becomes longer as approaching the other side in the thickness direction. The printed circuit board described in 1. is included.

  In this printed circuit board, since the magnetic layer covers one surface in the thickness direction exposed from the second insulating layer in the first insulating layer, the magnetic particles in the magnetic layer can be oriented along the orthogonal direction. it can.

  Further, the second corner formed by the other surface and the side surface has a portion in which the length between the two side surfaces facing each other becomes longer as it approaches the other surface, so that the portion is covered via the second insulating layer. In the magnetic layer, the magnetic particles can be oriented in a direction inclined with respect to the orthogonal direction, corresponding to the portion at the second corner.

  Therefore, a smooth magnetic path can be formed around the second corner. Therefore, the printed circuit board has a much higher inductance.

  In the present invention (8), the wiring has a substantially circular shape, the second insulating layer covers a peripheral surface of the wiring, and the particle-containing layer is interposed through the second insulating layer. The wired circuit board according to any one of (2) to (4), which covers the peripheral surface of the wiring.

  In the magnetic layer around the wiring, the magnetic particles can form a smooth magnetic path along the peripheral surface of the wiring. Therefore, the effective magnetic permeability around the wiring can be improved. As a result, the printed circuit board has a high inductance.

  The present invention (9) includes a first step of preparing a first insulating layer and a wiring disposed on one surface in the thickness direction of the first insulating layer, and a second step of covering the wiring with a second insulating layer. And a third step of forming a particle-containing layer containing conductive particles having a shape with an aspect ratio of 2 or more, covering the wiring via the second insulating layer, A wiring circuit that forms a substantially curved shape, and in the second step, heat-presses a particle-containing sheet containing the conductive particles oriented in a direction orthogonal to the thickness direction against the second insulating layer. A method for manufacturing a substrate is included.

  However, in the second step, when the particle-containing sheet is hot-pressed against the second insulating layer, the conductive particles contained in the particle-containing sheet easily pass through the second insulating layer and contact the wiring. .

  However, in this method for manufacturing a printed circuit board, since the wiring forms a substantially curved shape in the first step, the second insulating layer covering the portion corresponding to the substantially curved shape in the wiring can be formed thick.

  Therefore, the penetration of the conductive particles into the second insulating layer and the contact of the conductive particles with the wiring can be suppressed.

  Therefore, this manufacturing method can provide a printed circuit board that ensures the insulation of the second insulating layer.

  The present invention (10) is the method for producing a printed circuit board according to (9), wherein the conductive particles are magnetic particles, the particle-containing layer is a magnetic layer, and the method for producing a magnetic wired circuit board. Including methods.

  In the second step of the method of manufacturing a printed circuit board, which is a method of manufacturing a magnetic printed circuit board, a magnetic sheet containing conductive particles oriented in a direction perpendicular to the thickness direction is hot pressed against the second insulating layer. Therefore, the magnetic particles can be oriented along the curved shape of the wiring in the magnetic layer covering the portion corresponding to the substantially curved shape in the wiring via the second insulating layer. That is, the magnetic particles can be oriented in a direction inclined with respect to the thickness direction and the orthogonal direction in the magnetic layer facing the portion corresponding to the substantially curved shape of the wiring. Therefore, a smooth magnetic path can be formed along the portion corresponding to the substantially curved shape of the wiring in the magnetic layer. Therefore, the effective magnetic permeability around the wiring can be improved. As a result, a printed circuit board having high inductance can be manufactured.

  According to the present invention (11), the wiring in the first step is arranged such that the wiring in the thickness direction is opposed to the one surface in the thickness direction of the first insulating layer with a space therebetween, and the thickness of the first insulating layer. The other surface in the thickness direction that contacts one surface in the direction, and the side surface that connects both edges of the one surface in the thickness direction and the other surface in the thickness direction. A curved corner is formed, and in the second step, the insulating layer covers the one side surface and the side surface of the wiring in the thickness direction, and in the third step, the second insulating layer is interposed therebetween. The method for producing a printed circuit board according to (10), wherein a particle-containing layer that covers the one surface in the thickness direction and the side surface of the wiring is formed.

  In this method of manufacturing a printed circuit board, since the corner portion having a substantially curved shape is formed in the wiring in the first step, the second insulating layer covering the corner portion can be formed thick.

  Therefore, the penetration of the conductive particles into the second insulating layer and the contact of the conductive particles with the wiring can be suppressed.

  Therefore, this manufacturing method can provide a printed circuit board that ensures the insulation of the second insulating layer.

  In the present invention (12), in the first step, the subtractive method is used to form a wiring base having a pointed portion formed by one surface and a side surface in the thickness direction, and the wiring base is formed by plating. A fifth step of forming the corner portion from the covering portion into a substantially curved shape by forming the plating layer having a covering portion that covers the pointed portion. 11) A method for manufacturing a printed circuit board according to 11).

  However, if a wiring having a sharp portion is formed in the first step, the thickness of the insulating layer facing the sharp portion may be excessively thinned in the second step. Thereafter, in the third step, if the magnetic layer is formed, the magnetic particles pass through the insulating layer facing the pointed portion and come into contact with the pointed portion. As a result, the contact causes the magnetic layer and the wiring to Insulating properties may not be ensured.

  However, even in the fourth step, even if the wiring base portion having the sharp portion is formed, in the fifth step, the plating layer having the covering portion that covers the sharp portion is formed, and the corner portion is substantially separated from the covering portion. It is formed in a curved shape. Therefore, in the second step, the second insulating layer that covers the corner portion can be formed while suppressing excessive thinning.

  In the third step, by forming the magnetic layer, it is possible to suppress the magnetic particles in the magnetic layer from penetrating the second insulating layer and coming into contact with the wiring.

  In the invention (13), the wiring in the first step has a substantially circular shape, and in the second step, the peripheral surface of the wiring is covered with the insulating layer, and in the third step, the wiring The method for producing a printed circuit board according to (10), wherein a particle-containing layer that covers the peripheral surface of the wiring is formed via a second insulating layer.

  In the third step, in the magnetic layer around the wiring, the magnetic particles can form a smooth magnetic path along the substantially curved shape of the wiring. Therefore, the effective magnetic permeability around the wiring can be improved. As a result, a printed circuit board having high inductance can be manufactured.

  The wired circuit board of the present invention obtained by the method for manufacturing a wired circuit board of the present invention can ensure the insulation of the second insulating layer.

FIG. 1 shows a sectional view of a magnetic wired circuit board as an embodiment of the wired circuit board of the present invention and a partially enlarged sectional view thereof. 2A to 2D are manufacturing process diagrams of the magnetic wiring circuit board shown in FIG. 1. FIG. 2A is a fourth process (first process) for forming a wiring base, and FIG. 2B is a process for forming a plating layer. FIG. 2C shows a second step of forming the second insulating layer, and FIG. 2D shows a third step of forming the magnetic layer. FIG. 3 is a cross-sectional view for explaining a circular arc of a circle passing through the curved surface of the first corner in FIG. FIG. 4 is a partially enlarged cross-sectional view of a modified example of the magnetic wiring circuit board (an aspect in which the plating layer is thin and the wiring side surface does not have a constricted portion) in FIG. FIG. 5 is a partially enlarged cross-sectional view of a modified example of the magnetic wiring circuit board (embodiment in which the second corner portion has a vertical surface) in FIG. FIG. 6 is a partially enlarged cross-sectional view of a modification of the magnetic wiring circuit board shown in FIG. 1 (a mode in which the second corner portion has the first constricted surface). FIG. 7 is a partially enlarged cross-sectional view of a modified example of the magnetic wiring circuit board (an aspect in which the second corner portion has a second constricted surface) in FIG. 8A to 8C are manufacturing process diagrams of a modified example of the magnetic wiring circuit board shown in FIG. 1 (an embodiment in which the wiring part has a substantially circular cross section). FIG. 8A shows the first insulating layer, the wiring part, and the Step of preparing two insulating layers, FIG. 8B is a step of disposing the wiring portion and the second insulating layer on the first insulating layer, and FIG. 8C is a magnetic sheet of the first insulating layer, the wiring portion and the second insulating layer. Shows a hot press process. 9A to 9B are manufacturing process diagrams of the magnetic wiring circuit board of the comparative example. FIG. 9A shows a second process for forming the second insulating layer, and FIG. 9B shows a third process for forming the magnetic layer. .

<One Embodiment>
A magnetic wired circuit board 1 which is an embodiment of the wired circuit board of the present invention will be described with reference to FIG.

  The magnetic printed circuit board 1 has a thickness direction one surface and the other surface facing each other in the thickness direction, and has a shape extending in the surface direction (a direction orthogonal to the thickness direction). The magnetic wiring circuit board 1 includes a first insulating layer 2 that is an example of an insulating layer, a wiring portion 3 that is an example of wiring, a second insulating layer 4, and a magnetic layer 5 that is an example of a particle-containing layer. .

  The first insulating layer 2 has a shape extending in the surface direction. The first insulating layer 2 is a support material that supports the wiring portion 3 described below, and by extension, is also a support layer that supports the magnetic wiring circuit board 1. The first insulating layer 2 has a first insulating surface 7 that is one surface in the thickness direction and a second insulating surface 8 that is the other surface. Each of the first insulating surface 7 and the second insulating surface 8 is a flat surface along the surface direction. The first insulating layer 2 has flexibility.

  Examples of the material of the first insulating layer 2 include resins such as polyimide resin, polyester resin, and acrylic resin. The first insulating layer 2 may be either a single layer or a multilayer. The thickness of the 1st insulating layer 2 is not specifically limited, For example, they are 1 micrometer or more and 1000 micrometers or less.

  The wiring portion 3 is a cut surface cut along the thickness direction and the first direction (corresponding to the left-right direction in FIG. 1 and included in the surface direction) on the first insulating surface 7 of the first insulating layer 2. In FIG. 2, a plurality are arranged in the first direction at intervals. The shape of the wiring part 3 in plan view (when viewed in the thickness direction) is not particularly limited, and includes, for example, a loop shape (such as a coil shape).

  The wiring portion 3 includes a first wiring surface 9 that is one surface in the thickness direction and is disposed opposite to the first insulating surface 7 of the first insulating layer 2 with a space on one side in the thickness direction, and the first insulating layer 2. A second wiring surface 10 in contact with the first insulating surface 7, and a wiring side surface 11 that is a side surface connecting the first wiring surface 9 and both end edges in the first direction of the second wiring surface 10.

  The first wiring surface 9 is a flat surface along the first direction.

  The second wiring surface 10 is disposed so as to face the first wiring surface 9 with a gap in the thickness direction, and is a flat surface parallel to the first wiring surface 9.

  The wiring side surface 11 extends along the thickness direction. Two wiring side surfaces 11 are provided in one wiring part 3. The two wiring side surfaces 11 are arranged to face each other (facing each other) with a space therebetween in the first direction.

  The wiring portion 3 includes a first corner portion 21 and a second corner portion 22 as an example of a corner portion.

  The first corner portion 21 is a ridge line portion (first ridge line portion) formed by the first wiring surface 9 and the wiring side surface 11 in the wiring portion 3. Specifically, the first corner portion 21 is formed over both end portions in the first direction of the first wiring surface 9 and one end portion in the thickness direction of the wiring side surface 11 continuous therewith. Two first corner portions 21 are formed for each wiring portion 3.

  And this 1st corner | angular part 21 has a substantially curved shape in the cross section (cut surface along a thickness direction and a 1st direction). Specifically, the first corner 21 has a curved surface (specifically, a substantially arcuate surface) 23 that swells outward in the first direction and toward one side in the thickness direction.

  The center CP of the circle C forming the curved surface 23 (arc surface) is located, for example, inside the wiring portion 3.

  The radius (curvature radius) R of the circle C forming the curved surface 23 is, for example, 5 μm or more, preferably 9 μm or more, more preferably 15 μm or more, further preferably 20 μm or more, and for example, 30 μm or less. is there. If the radius of curvature R of the curved surface 23 is equal to or greater than the above lower limit, the curved surface 23 can be made gentle, and the second insulating layer 4 described below can be more reliably formed with a sufficient thickness T. . In addition, the magnetic particles 18 (described later) can be reliably oriented along the curved surface 23 in the second insulating layer 4 facing the first corner 21.

  If the curvature radius R of the first corner portion 21 is equal to or less than the above upper limit, the magnetic layer 5 can be filled in the thickness direction central portion 50 (described later) of the wiring side surface 11 without a gap (void).

  The central angle α of the curved surface 23 is an angle formed by a line segment connecting one end of the arc and the center CP and a line segment connecting the other end of the arc and the center CP, and is, for example, less than 180 degrees. Specifically, the central angle α of the curved surface 23 is, for example, 45 degrees or more, preferably 60 degrees or more, more preferably 80 degrees or more, and for example, 150 degrees or less, preferably 135 degrees. Below, more preferably, it is 120 degrees or less. If the central angle α of the curved surface 23 is equal to or greater than the above lower limit, the length of the curved surface 23 can be increased, so that the magnetic particles 18 can surely follow (orient) the curved surface 23. If the central angle α of the curved surface 23 is equal to or greater than the above lower limit, the length of the curved surface 23 can be increased, so that the magnetic particles 18 can surely follow (orient) the curved surface 23. If the central angle α of the curved surface 23 is equal to or less than the above upper limit, the magnetic layer 5 can be filled without a gap (void) in the thickness direction central portion 50 (described later) of the wiring side surface 11.

  In addition, as shown in the enlarged view of FIG. 1, the center CP is determined so that the circle C forming the curved surface 23 forms an arc that passes through the curved surface 23 at the maximum (overlapping) at the first corner portion 21; It is defined as a circle C based on the center CP. On the other hand, as shown in FIG. 3, a center CP ′ that forms an arc that slightly (minimally) passes (overlaps) the curved surface 23 at the first corner 21 is determined, and a circle based on the center CP ′ is determined. Not C '.

  The second corner portion 22 is a ridge line portion (second ridge line portion) formed by the second wiring surface 10 and the wiring side surface 11 in the wiring portion 3. Specifically, the second corner portion 22 is formed over each of both end portions in the first direction of the second wiring surface 10 and the other end portion in the thickness direction of the wiring side surface 11 continuous therewith. Two second corner portions 22 are formed for each wiring portion 3.

  Each of the two second corner portions 22 is disposed on the other side in the thickness direction with respect to each of the two first corner portions 21.

  The 2nd corner | angular part 22 is a 2nd pointed part sharpened toward the 1st direction outer side (1st direction outer side diagonal 1st direction other side). The second corner 22 has an inclined surface 24 and a flat surface 26 (partitioned by).

  The inclined surface 24 has a tapered surface 27 as a main part. Preferably, the inclined surface 24 comprises only the tapered surface 27. The inclined surface 24 is continuous from the central portion 50 in the thickness direction of the wiring side surface 11 (specifically, the vicinity between the central portion and the other end portion) 50 and faces the outside in the first direction. The two inclined surfaces 24 corresponding to the two second corner portions 22 are disposed to face each other (facing each other) in the first direction.

  The tapered surface 27 is inclined with respect to the thickness direction and the first direction. That is, the tapered surface 27 is inclined with respect to the thickness direction and the first direction, and is inclined to the outside in the first direction as it goes to the other side in the thickness direction (first inclination direction) (shown together with the enlarged view). Direction arrow). The two taper surfaces 27 corresponding to the two inclined surfaces 24 are two taper surfaces (an example of a part) which become longer as the distance between them approaches the other side in the thickness direction. Specifically, the taper surface 27 extends from the central portion 50 in the thickness direction of the wiring side surface 11 (specifically, between the central portion and the other end portion) 50 to both edges in the first direction of the second wiring surface 10 (first As it goes to the first insulating surface 7) of the insulating layer 2, it inclines so as to spread outwardly in the first direction. In addition, the taper ratio (first direction length / thickness direction length) obtained by dividing the length in the first direction by the length in the thickness direction of the tapered surface 27 is, for example, 0.001 or more, preferably 0.01 or more. More preferably, it is 0.1 or more, for example, 1.0 or less, preferably 0.75 or less.

  The flat surface 26 is a plane that extends straight from the other end in the thickness direction of the inclined surface 24 toward the inside in the first direction. The flat surface 26 corresponds to both edges of the second wiring surface 10 in the first direction. The flat surface 26 is in contact with the first insulating surface 7.

  The inclined surface 24 of the second corner 22 and the curved surface 23 of the first corner 21 are disposed, for example, with a central portion 50 in the thickness direction of the wiring side surface 11 being separated.

  In addition, this 2nd corner | angular part 22 may be the same shape as the 2nd pointed part 45 (refer FIG. 2A) in the wiring base part 36 mentioned later.

  The wiring side surface 11 is a portion facing the first direction outside of the curved surface 23 of the first corner portion 21, a portion in the thickness direction center portion 50, and a portion facing the first direction outside of the inclined surface 24 of the curved surface 23. Are provided continuously.

  Each of the central portions 50 in the thickness direction of the two wiring side surfaces 11 has a shape constricted toward the inside in the first direction. Specifically, the wiring side surface 11 has a shape (necked portion) in which the length between them is the shortest in the central portion in the first direction.

  In addition, the wiring part 3 is provided with the wiring base part 36 and the plating layer 30 formed in the thickness direction one surface and both side surfaces, for example, as shown with the virtual line of FIG. 2B.

  As a material of the wiring part 3, conductors, such as metals, such as copper, nickel, gold | metal | money, solder, and alloys of those metals, are mentioned, for example, Preferably, copper is mentioned.

  The thickness of the wiring part 3 is the length between the first wiring surface 9 and the second wiring surface 10, specifically, for example, 10 μm or more, preferably 30 μm or more, and, for example, 500 μm or less. The thickness is preferably 250 μm or less.

  The width of the wiring part 3 is, for example, 20 μm or more, preferably 50 μm or more, for example, 2000 μm or less, preferably, as the distance between the edges in the first direction of the two first corners 21 facing each other. 1000 μm or less.

The interval between the adjacent wiring portions 3 is, for example, 20 μm or more as the interval between the first direction edges of the first corner portions 21 adjacent to each other across the second insulating layer 4 (described later) and the magnetic layer 5 (described later). The thickness is preferably 50 μm or more, and for example, 1000 μm or less, preferably 500 μm or less.
The ratio (thickness / width) of the thickness of the wiring part 3 to the width of the wiring part 3 is, for example, 0.005 or more, preferably 0.03 or more, and for example, 25 or less, preferably 5 or less. It is. The ratio (thickness / interval) of the thickness of the wiring part 3 to the distance between adjacent wiring parts 3 is, for example, 0.01 or more, preferably 0.06 or more, and for example, 25 or less, preferably 5 or less. The ratio (width / interval) of the width of the wiring part 3 to the distance between adjacent wiring parts 3 is, for example, 0.02 or more, preferably 0.01 or more, and for example, 100 or less, preferably , 20 or less.

  The wiring part 3 is provided in the printed circuit board preparation body 6 together with the first insulating layer 2 described above. That is, the printed circuit board preparation 6 does not include the second insulating layer 4 and the magnetic layer 5 described below, but includes the first insulating layer 2 and the wiring portion 3. Preferably, the printed circuit board preparation 6 includes only the first insulating layer 2 and the wiring portion 3.

  A plurality of second insulating layers 4 are provided corresponding to the plurality of wiring portions 3. The second insulating layer 4 is formed in a thin film shape along the first wiring surface 9 and the wiring side surface 11 (including the curved surface 23 and the inclined surface 24) of the wiring part 3. The second insulating layer 4 is disposed at a distance from the fourth insulating surface 13 in contact with the first wiring surface 9 and the wiring side surface 11 and one side in the thickness direction of the fourth insulating surface 13 or outside in the first direction. 3 insulating surfaces 12.

  The fourth insulating surface 13 has a shape corresponding to the first wiring surface 9 and the wiring side surface 11 (specifically, the same).

  The third insulating surface 12 has a shape that follows the fourth insulating surface 13 so that the thickness T of the second insulating layer 4 is ensured. The third insulating surface 12 has a shape parallel to the fourth insulating surface 13.

  Moreover, the 2nd insulating layer 4 is an electrodeposition layer (after-mentioned), an application layer (after-mentioned) etc., for example, Preferably, it is an electrodeposition layer.

  The second insulating layer 4 is, for example, relatively soft (in particular, has a property of being soft in a hot press in a third step described later (see FIG. 2D)), but does not have magnetism. Specifically, examples of the material of the second insulating layer 4 include a resin that does not contain the magnetic particles 18 (described in detail later in the magnetic layer 5). The resin of the second insulating layer 4 is preferably a resin that is ionic in water, and specifically includes acrylic resins, epoxy resins, polyimide resins, and mixtures thereof.

  The thickness T of the second insulating layer 4 is relatively thin, and the average thickness thereof is, for example, 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, further preferably 7.5 μm, and particularly preferably 5 μm. Hereinafter, it is most preferably 3 μm or less, for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more.

  If the thickness T of the second insulating layer 4 is as thin as the above upper limit, the effective magnetic permeability of the magnetic layer 5 described below can be improved and the inductance of the magnetic wiring circuit board 1 can be increased.

  On the other hand, when the second insulating layer 4 is excessively thin, magnetic particles in the magnetic layer 5 described later easily pass through the second insulating layer 4 and come into contact with the wiring portion 3.

  However, in this magnetic wired circuit board 1, the first corner 21 of the wiring part 3 has a substantially curved shape, so that the thickness T of the second insulating layer 4 is excessively thin. By suppressing this, it is possible to prevent the second insulating layer 4 from penetrating the magnetic particles 18, and to ensure the insulation of the second insulating layer 4.

  The thickness T1 of the portion covering the first corner 21 in the second insulating layer 4 is a portion other than the first corner 21 described above in the second insulating layer 4 (for example, the central portion 50 in the thickness direction of the wiring side surface 11). And / or the thickness T0 of the portion covering the first wiring surface 9 in the first direction center) or slightly smaller than the thickness T0 is allowed.

  In the second insulating layer 4, the ratio (T1 / T0) of the thickness T1 of the portion covering the first corner 21 to the thickness T0 of the portion covering the portion other than the first corner 21 is, for example, 1 or less, Preferably, it is less than 1, more preferably 0.95 or less, still more preferably 0.9 or less, and for example 0.7 or more, preferably 0.8 or more.

  The thickness T1 of the portion covering the first corner 21 in the second insulating layer 4 is, for example, 0.5 μm or more, preferably 1 μm or more, and for example, 10 μm or less, preferably 7 μm or less.

  The thickness T0 of the portion covering the other portion in the second insulating layer 4 is, for example, 0.52 μm or more, preferably 1.04 μm or more, and, for example, 14.49 μm or less, preferably 10.14 μm. It is as follows.

  The average thickness of the second insulating layer 4 is calculated by dividing the above-described thicknesses T1 and T0 by the area ratio.

  The magnetic layer 5 is provided to the printed circuit board preparation 6 in order to improve the inductance of the magnetic wired circuit board 1. The magnetic layer 5 has a shape extending in the plane direction.

  In the magnetic layer 5, the wiring part 3 is embedded via the second insulating layer 4. Specifically, the magnetic layer 5 covers the first wiring surface 9 and the wiring side surface 11 (including the curved surface 23 and the inclined surface 24) of the wiring part 3 via the second insulating layer 4. The magnetic layer 5 covers the exposed surface 16 exposed from the second insulating layer 4 on the first insulating surface 7 of the first insulating layer 2.

  The magnetic layer 5 has a first magnetic surface 14 and a second magnetic surface 15.

  The first magnetic surface 14 is disposed at an interval on one side in the thickness direction with respect to the third insulating surface 12 of the second insulating layer 4. The first magnetic surface 14 is exposed on one side in the thickness direction. The first magnetic surface 14 is disposed between a plurality of convex portions 28 that protrude toward one side in the thickness direction corresponding to the plurality of wiring portions 3 and the convex portions 13 that are adjacent to each other. And a recess 29 that sinks toward the other side in the thickness direction.

  The second magnetic surface 15 is arranged at an interval on the other side in the thickness direction of the first magnetic surface 14. The second magnetic surface 15 is in continuous contact with the third insulating surface 12 and the exposed surface 16.

  The magnetic layer 5 contains, for example, magnetic particles 18. Specifically, examples of the material for the magnetic layer 5 include a magnetic composition containing the magnetic particles 18 having an aspect ratio of 2 or more and the resin component 19.

  Examples of the magnetic material constituting the magnetic particle 18 include a soft magnetic material and a hard magnetic material. Preferably, a soft magnetic material is used from the viewpoint of inductance.

  As the soft magnetic material, for example, a single metal body containing one kind of metal element in a pure substance state, for example, one or more kinds of metal elements (first metal element) and one or more kinds of metal elements (second An alloy body which is a eutectic (mixture) with a metal element) and / or a non-metal element (carbon, nitrogen, silicon, phosphorus, etc.) can be used. These can be used alone or in combination.

  As a single metal body, the metal simple substance which consists only of one type of metal element (1st metal element) is mentioned, for example. The first metal element is appropriately selected from, for example, iron (Fe), cobalt (Co), nickel (Ni), and other metal elements that can be contained as the first metal element of the soft magnetic material. .

  In addition, as a single metal body, for example, a form including a core containing only one kind of metal element and a surface layer containing an inorganic substance and / or an organic substance that modifies part or all of the surface of the core, for example, Examples include a form in which an organometallic compound or an inorganic metal compound containing the first metal element is decomposed (such as thermal decomposition). More specifically, as the latter form, iron powder obtained by thermally decomposing an organic iron compound (specifically, carbonyl iron) containing iron as the first metal element (sometimes referred to as carbonyl iron powder). Etc. Note that the position of the layer containing an inorganic material and / or an organic material that modifies a portion containing only one type of metal element is not limited to the above surface. In addition, it does not restrict | limit especially as an organic metal compound and an inorganic metal compound which can obtain a single metal body, The well-known thru | or usual organic metal compound and inorganic metal compound which can obtain the single metal body of a soft magnetic body Can be appropriately selected.

  An alloy body is a eutectic mixture of one or more metal elements (first metal element) and one or more metal elements (second metal element) and / or non-metal elements (carbon, nitrogen, silicon, phosphorus, etc.). The body is not particularly limited as long as it can be used as an alloy body of a soft magnetic body.

  The first metal element is an essential element in the alloy body, and examples thereof include iron (Fe), cobalt (Co), and nickel (Ni). If the first metal element is Fe, the alloy body is an Fe-based alloy, and if the first metal element is Co, the alloy body is a Co-based alloy, and the first metal element is Ni. In this case, the alloy body is a Ni-based alloy.

  The second metal element is an element (subcomponent) that is secondary contained in the alloy body, and is a metal element that is compatible (eutectic) with the first metal element, for example, iron (Fe) (first 1 metal element other than Fe), cobalt (Co) (when the first metal element is other than Co), nickel (Ni) (when other than the first metal element Ni), chromium (Cr), aluminum (Al), silicon (Si), copper (Cu), silver (Ag), manganese (Mn), calcium (Ca), barium (Ba), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), ruthenium (Ru), rhodium (Rh), zinc (Zn), gallium (Ga), indium (In), germanium (Ge , Tin (Sn), lead (Pb), scandium (Sc), yttrium (Y), strontium (Sr), and various rare earth elements and the like. These can be used alone or in combination of two or more.

  The nonmetallic element is an element (subcomponent) that is secondary to the alloy body, and is a nonmetallic element that is compatible (eutectic) with the first metal element. For example, boron (B), carbon (C), nitrogen (N), silicon (Si), phosphorus (P), sulfur (S) and the like. These can be used alone or in combination of two or more.

  As an Fe-based alloy which is an example of an alloy body, for example, magnetic stainless steel (Fe—Cr—Al—Si alloy) (including electromagnetic stainless steel), sendust (Fe—Si—Al alloy) (including super sendust), permalloy ( Fe-Ni alloy), Fe-Ni-Mo alloy, Fe-Ni-Mo-Cu alloy, Fe-Ni-Co alloy, Fe-Cr alloy, Fe-Cr-Al alloy, Fe-Ni-Cr alloy, Fe- Ni-Cr-Si alloy, silicon copper (Fe-Cu-Si alloy), Fe-Si alloy, Fe-Si-B (-Cu-Nb) alloy, Fe-B-Si-Cr alloy, Fe-Si-Cr -Ni alloy, Fe-Si-Cr alloy, Fe-Si-Al-Ni-Cr alloy, Fe-Ni-Si-Co alloy, Fe-N alloy, Fe-C alloy, Fe-B alloy, Fe-P alloy , Ferrite (stainless steel Soft ferrite such as Mn-Mg ferrite, Mn-Zn ferrite, Ni-Zn ferrite, Ni-Zn-Cu ferrite, Cu-Zn ferrite, Cu-Mg-Zn ferrite ), Permendur (Fe—Co alloy), Fe—Co—V alloy, Fe-based amorphous alloy, and the like.

  Examples of the Co-based alloy that is an example of an alloy body include Co—Ta—Zr, cobalt (Co) based amorphous alloy, and the like.

  Examples of the Ni-based alloy that is an example of an alloy body include a Ni—Cr alloy.

  Among these soft magnetic materials, from the viewpoint of magnetic properties, an alloy body, more preferably an Fe-based alloy, more preferably Sendust (Fe-Si-Al alloy), and particularly preferably a high magnetic permeability is obtained. From the viewpoint, Sendust having a Si content ratio of 9 to 15% by mass can be mentioned. The soft magnetic material is preferably a single metal body, more preferably a single metal body containing an iron element in a pure substance state, more preferably an iron simple substance or iron powder (carbonyl iron powder). Can be mentioned.

  Examples of the shape of the magnetic particle 18 include a flat shape (plate shape) having a small thickness and a wide surface, for example, a shape having anisotropy such as a needle shape. Further, non-anisotropic magnetic particles can be further contained. The non-anisotropic magnetic particles may have a shape such as a spherical shape, a granular shape, a lump shape, or a pellet shape. The shape of the magnetic particle 18 is preferably a shape having anisotropy.

  When the magnetic particles 18 are flat, the aspect ratio of the magnetic particles is 2 or more, preferably 5 or more, more preferably 10 or more, still more preferably 20 or more, and 100 or less.

  The flatness (flatness) when the magnetic particles 18 are flat is, for example, 8 or more, preferably 15 or more, and for example, 500 or less, preferably 450 or less. The flatness is, for example, an aspect ratio obtained by dividing the average particle diameter (average length) of the magnetic particles 18 by the average thickness of the magnetic particles 18.

  The content ratio of the magnetic particles 18 in the magnetic layer 5 (magnetic composition) is, for example, 50% by volume or more, preferably 55% by volume or more, and, for example, 95% by volume or less, preferably 90% by volume or less. It is.

  Examples of the resin component 19 include thermosetting resins such as an epoxy resin composition containing an epoxy resin, a curing agent, and a curing accelerator. In addition, such a magnetic composition is described in Unexamined-Japanese-Patent No. 2017-005115, Unexamined-Japanese-Patent No. 2015-092543, etc., for example.

  The thickness of the magnetic wiring circuit board 1 is, for example, 30 μm or more, preferably 50 μm or more, and, for example, 1000 μm or less, preferably 800 μm or less as its maximum thickness (thickness corresponding to the convex portion 28). .

  Next, the manufacturing method of this magnetic wiring circuit board 1 is demonstrated with reference to FIG. 2A-FIG. 2D.

  This manufacturing method includes a first step (see FIGS. 2A and 2B) as an example of a step of preparing the first insulating layer 2 and the wiring portion 3, and a second step of forming the second insulating layer 4 (FIG. 2C). And a third step (see FIG. 2D) as an example of a step of forming the magnetic layer 5.

  As shown in FIGS. 2A and 2B, in the first step, a printed circuit board preparation body 6 including the first insulating layer 2 and the wiring portion 3 is prepared. The first step includes a step of preparing the first insulating layer 2 (see FIG. 2A), a fourth step of forming the wiring base 36 (see FIG. 2A), and a fifth step of forming the plating layer 30 (FIG. 2B). See).

  In the fourth step, the wiring base 36 is formed on the first insulating surface 7 of the first insulating layer 2 by, for example, a conductor patterning method such as a subtractive method or an additive method.

  In order to form the wiring base 36 by the subtractive method, first, a laminated body (not shown) composed of the first insulating layer 2 and the conductor layer (metal layer) is prepared, and subsequently, one side in the thickness direction of the conductor layer. In addition, an etching resist is formed in the same pattern as the wiring base 36. Next, the conductor base exposed from the etching resist is patterned by, for example, etching such as wet etching or dry etching to form the wiring base 36. Preferably, the wiring base 36 is formed by wet etching. Thereafter, the etching resist is removed by, for example, peeling.

  In order to form the wiring base 36 by the additive method, first, a conductive thin film (seed film) is formed on the first insulating surface 7 of the first insulating layer 2, and then the wiring base is formed on one surface in the thickness direction of the conductive thin film. A plating resist having a pattern opposite to that of 36 is formed. Next, the wiring base 36 is formed on the conductive thin film exposed from the plating resist by plating. Thereafter, the plating resist and the corresponding conductive thin film are removed.

  The conductor patterning method is preferably a subtractive method. If it is a subtractive method, compared with an additive method, the wiring base part 36 which has a thick thickness can be formed rapidly.

  On the other hand, if the wiring base portion 36 is formed by the subtractive method, the first sharpened portion 25 is formed in the wiring base portion 36. However, as described later, the second insulating layer 4 is caused by the first sharpened portion 25. The thinning can be solved by the plating layer 30 formed in the fifth step described later.

  The wiring base 36 is a base (base) for forming the wiring part 3 and forms the wiring part 3 together with a plating layer 30 described later. That is, the wiring part 3 is not configured only by the wiring base part 36 shown in FIG. 2A.

  The wiring base portion 36 includes a first sharpened portion 25 corresponding to the first corner portion 21, a base central side surface 51 corresponding to the thickness direction central portion 50, and a second sharpened portion 45 corresponding to the second corner portion 22. .

  The first sharpened portion 25 is a ridge line portion formed by one surface and a side surface in the thickness direction of the wiring base portion 36. The first sharpened portion 25 sharply sharpens toward the one side in the first direction outer side obliquely in the first direction. The angle (angle formed by the ends of the first wiring surface 9 and the wiring side surface 11) β1 at the first sharpened portion 25 is, for example, 135 degrees or less, preferably 120 degrees or less, more preferably 90 degrees or less. Yes, for example, 30 degrees or more, preferably 45 degrees or more.

  The second sharpened portion 45 is a ridge line portion formed by the other surface and the side surface in the thickness direction of the wiring base portion 36. The second sharpened portion 45 sharply sharpens toward the other side of the first direction outer side obliquely in the first direction. The angle (angle formed by the ends of the second wiring surface 10 and the wiring side surface 11) β2 at the second sharpened portion 45 is, for example, 35 degrees or more, preferably 45 degrees or more, more preferably more than 80 degrees. For example, it is 150 degrees or less, preferably 135 degrees or less.

  The base center side surface 51 is a connection surface that connects the first sharpened portion 25 and the second sharpened portion 45 in the thickness direction.

  The material of the wiring base portion 36 is the same as the material of the wiring portion 3 described above.

  In the fifth step, the plating layer 30 is then formed on the wiring base 36 as shown in FIG. 2B.

  The material of the plating layer 30 is appropriately selected from the material of the wiring base 36 and is preferably the same as the material of the wiring base 36.

  A plating layer 30 is formed by plating.

  Examples of the plating include electrolytic plating and electroless plating. Preferably, from the viewpoint of forming the plating layer 30 thick, electrolytic plating (more preferably, electrolytic copper plating) is used.

  The plating layer 30 is laminated on one side and both sides in the thickness direction of the wiring base 36 by plating. In the plating, the plating layer 30 is formed in a deposited state on one surface and both side surfaces in the thickness direction of the wiring base 36.

  By this plating, a first covering portion 31 as an example of a covering portion that grows (plating growth) toward one side in the thickness direction and the outside in the first direction is deposited on the first sharpened portion 25. The first covering portion 31 forms the first corner portion 21 having the curved surface 23.

  On the other hand, in the wiring base portion 36 other than the first sharpened portion 25 (the portion including the second sharpened portion 45 and the central portion 50 in the thickness direction), it grows (plating growth) toward one side in the thickness direction or outward in the first direction. The 2nd coating | coated part 32 precipitates. The second covering portion 32 forms one side surface and both side surfaces of the wiring base portion 36 (however, the portion excluding the first corner portion 21 and including the thickness direction central portion 50 and the inclined surface 24). .

  That is, the plating layer 30 includes a first covering portion 31 and a second covering portion 32. Preferably, the plating layer 30 includes only the first covering portion 31 and the second covering portion 32.

  The first covering portion 31 is formed by plating growth of the plating component from the first sharpened portion 25 in a substantially radial shape in sectional view (a fan shape excluding the direction inside the first sharpened portion 25). Therefore, the first covering part 31 has a curved surface 23.

  On the other hand, in the portions other than the first pointed portion 25, the second covering portion 32 is planar in a direction orthogonal to each surface, specifically, in one thickness direction of the wiring base portion 36 toward the upper side in the thickness direction. The plating component grows on the both sides of the wiring base portion 36 (including the side surface of the second sharpened portion 45), and the plating component grows in a planar shape toward both outer sides in the first direction. Therefore, the 2nd coating | coated part 32 does not have the above-mentioned curved surface 23, but has the 1st wiring surface 9 and the wiring side surface 11 (The thickness direction center part 50 is included, but the curved surface 23 is excluded).

  This 2nd coating | coated part 32 contains the 2nd corner | angular part 22, This 2nd corner | angular part 22 contains the inclined surface 24 based on the above-mentioned plating growth.

  In the plating layer 30, the thickness (growth thickness or plating thickness) of the first covering portion 31 is preferably thicker than that of the second covering portion 32. If the plating is electrolytic plating, the current density at the first sharpened portion 25 is higher than the current density of the wiring base 36 other than the first sharpened portion 25. Therefore, the plating growth of the first covering portion 31 is faster than the plating growth of the second covering portion 32, and thus the thickness of the first covering portion 31 is thicker than the thickness of the second covering portion 32.

  The thickness of the plating layer 30 is appropriately set according to the growth rate of plating and the plating time. These include, for example, metal (conductor) concentration and temperature in the plating solution used in plating, for example, if the plating is electrolytic plating, current density, distance between electrodes, degree of agitation in bath (speed), copper sulfate Concentration, sulfuric acid concentration, chloride ion concentration, type and amount of additives (leveler, brightener, polymer), for example, if the plating is electroless plating, the type and amount of catalyst attached to the surface of the wiring base 36 It sets suitably by these.

  As shown in FIG. 2B, a boundary indicated by an imaginary line is shown between the wiring base 36 and the plating layer 30, but the material of the plating layer 30 is the same as the material of the wiring base 36. If present, the above-mentioned boundary is obscured or does not exist (not observed).

  In the plating layer 30, the first covering portion 31 is formed by the above plating, and thus has the curved surface 23 described above. On the other hand, the second covering portion 32 has an inclined surface 24.

  In the second step, as shown in FIG. 2C, the second insulating layer 4 is subsequently formed on the printed circuit board preparation 6 described above. Specifically, the second insulating layer 4 covers the first wiring surface 9 and the wiring side surface 11 of the wiring part 3.

  Examples of the method for forming the second insulating layer 4 include electrodeposition (electrodeposition coating), for example, coating such as printing.

  In the electrodeposition, the printed circuit board preparation 6 (the magnetic wiring circuit board 1 being manufactured) is immersed in an electrodeposition liquid containing a resin (preferably an electrodeposition paint), and then a current is applied to the wiring section 3. By applying, a resin film is deposited on the first wiring surface 9 and the wiring side surface 11 of the wiring part 3. Thereafter, the coating is dried if necessary. Thereby, the 2nd insulating layer 4 is formed as an electrodeposition layer. Thereafter, if necessary, the second insulating layer 4 (electrodeposition layer) is heated and cured by baking.

  In printing, which is an example of application, a coating is applied to the first wiring surface 9 and the wiring side surface 11 of the wiring portion 3 with a varnish containing a resin through a screen (screen printing). Thereafter, the coating is dried.

  A preferred method for forming the second insulating layer 4 is electrodeposition. If it is electrodeposition, the thickness T of the second insulating layer 4 can be made thin (however, the thickness can be set to a level that can ensure the insulation of the second insulating layer 4). Moreover, if it is electrodeposition, the 2nd insulating layer 4 can expose the exposed surface 16 reliably, Therefore, between the adjacent wiring parts 3, in the following 3rd process, the magnetic layer 5 is made into thickness. Since it can arrange | position over the whole direction, the effective magnetic permeability of the magnetic layer 5 is improved and the inductance of the magnetic wiring circuit board 1 becomes high.

  In the third step, the magnetic layer 5 is then formed on the printed circuit board preparation 6 as shown in FIG. 2D. Specifically, the first wiring surface 9 and the wiring side surface 11 of the wiring part 3 are covered with the magnetic layer 5 via the second insulating layer 4.

  In the third step, for example, as shown in FIG. 2C, first, a magnetic sheet 17 as an example of a particle-containing sheet is prepared. In order to prepare the magnetic sheet 17, for example, the magnetic sheet 17 is formed into a sheet shape from a magnetic composition containing the above-described magnetic particles and a resin component (preferably a B-stage thermosetting resin). In the magnetic sheet 17, the magnetic particles 18 are oriented (arranged) in the surface direction of the magnetic sheet 17 (direction perpendicular to the thickness direction).

  Thereafter, as shown by the arrow in FIG. 2C, the magnetic sheet 17 is hot-pressed against the second insulating layer 4 of the printed circuit board preparation 6. The magnetic sheet 17 is disposed on one side in the thickness direction of the printed circuit board preparation body 6, and the magnetic sheet 17 is hot pressed against one surface in the thickness direction of the printed circuit board preparation body 6.

  Thereby, the magnetic sheet 17 embeds the wiring part 3 through the second insulating layer 4. Specifically, the magnetic sheet 17 covers the first wiring surface 9 of the second insulating layer 4 with the second insulating layer 4 interposed therebetween, and between the adjacent wiring portions 3 (opposed to the exposed surface 16). (Part) enters (sinks) and fills the part (part).

  In the magnetic sheet 17 before and after hot pressing, the orientation direction (specifically, the surface direction) of the magnetic particles 18 facing the first wiring surface 9 of the wiring part 3 does not vary. Further, in the magnetic sheet 17 before and after hot pressing, the orientation direction (specifically, the surface direction) of the magnetic particles 18 facing the exposed surface 16 does not vary.

  On the other hand, in the magnetic sheet 17 before and after hot pressing, the orientation direction (specifically, the surface direction) of the magnetic particles 18 facing the first corner portion 21 is the direction along the curved surface 23 (that is, the other side in the thickness direction). As it goes to the diagonal direction, the first direction is inclined outward. That is, the magnetic particles 18 described above are oriented along the curved surface 23.

  In the magnetic sheet 17 before and after the hot pressing, the orientation direction (specifically, the surface direction) of the magnetic particles 18 facing the second corner portion 22 is the direction along the inclined surface 24 (that is, the other side in the thickness direction). As it goes to the diagonal direction, the first direction is inclined outward. That is, the magnetic particles 18 described above are oriented along the inclined surface 24.

  On the other hand, in the magnetic sheet 17 before and after the hot press, the orientation direction (specifically, the plane direction) of the magnetic particles 18 facing the first corner portion 21 and the second corner portion 22 on the wiring side surface 11 is the thickness direction. It fluctuates in the direction along. That is, the above-described magnetic particles 18 are oriented along the thickness direction.

  Thus, the magnetic sheet 17 is formed (molded) as the magnetic layer 5 that covers the wiring portion 3 and has the convex portion 28 and the concave portion 29 via the second insulating layer 4.

  The magnetic particles 18 oriented as described above in the magnetic layer 5 form a smooth magnetic path surrounding the wiring portion 3.

  As a result, the magnetic wired circuit board 1 including the wired circuit board preparation 6 and the magnetic layer 5 is obtained. The magnetic wired circuit board 1 is preferably composed only of the wired circuit board preparation 6 and the magnetic layer 5.

  Thereafter, when the magnetic layer 5 contains a B-stage thermosetting resin, the magnetic layer 5 is C-staged (completely cured) by heating, for example, if necessary.

  The magnetic wiring circuit board 1 is used for, for example, wireless power transmission (wireless power feeding and / or wireless power receiving), wireless communication, a sensor, a passive component, and the like.

  And in this magnetic wiring circuit board 1, since the 1st corner | angular part 21 (part corresponding to a substantially curved shape in the wiring part 3) of the wiring part 3 has a substantially curved shape, this 1st corner | angular part 21 is coat | covered. The second insulating layer 4 can be formed while suppressing excessive thinning. Therefore, it is possible to suppress the magnetic particles 18 from penetrating the second insulating layer 4 and coming into contact with the wiring part 3. As a result, the second insulating layer 4 can ensure the insulation of the magnetic layer 5 with respect to the wiring portion 3.

  Further, in the magnetic layer 5 that covers the first corner portion 21 via the second insulating layer 4, the magnetic particles 18 can be oriented along the curved shape of the first corner portion 21. That is, the magnetic particles 18 are oriented in the plane direction in the magnetic layer 5 facing the first wiring surface 9 of the wiring part 3, and in the thickness direction in the magnetic layer 5 facing the wiring side surface 11 of the wiring part 3. The magnetic layer 5 that is oriented and faces the first corner 21 is oriented in a thickness direction and a direction that is inclined with respect to the first direction. Therefore, a smooth magnetic path surrounding the wiring part 3 can be formed in the magnetic layer 5. Therefore, the effective magnetic permeability around the wiring part 3 can be improved. As a result, the magnetic wired circuit board 1 has a high inductance.

  Therefore, this magnetic wired circuit board 1 is excellent in the insulation of the second insulating layer 4 while having a high inductance.

  Moreover, in this magnetic wiring circuit board 1, if the 2nd insulating layer 4 is an electrodeposition layer, the thickness of the 2nd insulating layer 4 can be made thin. Therefore, it is possible to suppress a decrease in effective magnetic permeability of the magnetic layer 5 that covers the wiring portion 3 via the second insulating layer 4. As a result, this magnetic wired circuit board 1 has a high inductance.

  On the other hand, as shown in FIG. 9A, when the thickness of the second insulating layer 4, specifically, the thickness T1 of the second insulating layer 4 facing the first sharpened portion 25 is thin, as shown in FIG. 9B. In addition, the magnetic particles 18 easily penetrate the thin second insulating layer 4 and come into contact with the wiring portion 3. However, in this magnetic wired circuit board 1, as shown in FIG. 1, the first corner portion 21 of the wiring portion 3 has a substantially curved shape, and the second insulating layer 4 that covers the first corner portion 21 is provided. Since the formation of an excessively thin thickness is suppressed, the penetration of the second insulating layer 4 by the magnetic particles 18 can be suppressed, and the insulating property of the second insulating layer 4 can be ensured.

  Moreover, in this magnetic wiring circuit board 1, if the curvature radius R of the 1st corner | angular part 21 is as large as 9 micrometers or more, since the curved surface 23 is gentle, the 2nd insulating layer 4 corresponding to the 1st corner | angular part 21 is provided. It can be formed with a sufficient thickness T1. In the second insulating layer 4 facing the first corner 21, the magnetic particles 18 can be reliably oriented along the curved surface 23.

  Further, if the average thickness T of the second insulating layer 4 is as thin as 10 μm or less, it is possible to suppress a decrease in the effective magnetic permeability of the magnetic layer 4. As a result, this magnetic wired circuit board 1 has a high inductance.

  Moreover, in this magnetic wiring circuit board 1, since the magnetic layer 5 coat | covers the exposed surface 16, the magnetic particle 18 in this magnetic layer 5 can be orientated along a surface direction.

  Further, the second corner portion 22 formed by the second wiring surface 10 and the wiring side surface 11 of the wiring portion 3 becomes longer as the length between the two wiring side surfaces 11 facing each other becomes closer to the second wiring surface 10. 27, in the magnetic layer 5 covered via the second insulating layer 4, the magnetic particles 18 can be oriented in a direction inclined with respect to the first direction corresponding to the tapered surface 27. .

  Therefore, a smooth magnetic path can be formed around the second corner 22. Therefore, the magnetic wired circuit board 1 has a much higher inductance.

  However, as shown in FIGS. 9A and 9B, when the magnetic sheet 17 is hot-pressed against the second insulating layer 4 in the second step, the magnetic particles 18 contained in the magnetic sheet 17 are second It is easy to penetrate the insulating layer 4 and contact the wiring part 3.

  However, as shown in FIG. 2B, in the method for manufacturing the magnetic wired circuit board 1, the first corner portion 21 having a substantially curved shape is formed in the wiring portion 3 in the first step. Thus, the second insulating layer 4 covering the first corner 21 can be formed thick.

  Therefore, the penetration of the magnetic particles 18 into the second insulating layer 4 and the contact of the magnetic particles 18 with the wiring can be suppressed.

  Therefore, this manufacturing method can obtain the magnetic wiring circuit board 1 which is excellent in the insulating property of the second insulating layer 4.

  In the second step, the magnetic sheet 17 containing the magnetic particles 18 oriented in the plane direction is hot-pressed against the second insulating layer 4, so that the first corner 21 is interposed via the second insulating layer 4. In the magnetic layer 5 that covers the magnetic layer 18, the magnetic particles 18 can be oriented along the curved shape of the first corner portion 21. That is, the magnetic particles 18 are oriented in the plane direction in the magnetic layer 5 facing the first wiring surface 9 of the wiring part 3, and in the thickness direction in the magnetic layer 5 facing the wiring side surface 11 of the wiring part 3. The magnetic layer 5 that is oriented and faces the first corner 21 can be oriented in the thickness direction and the direction inclined with respect to the first direction. Therefore, a smooth magnetic path surrounding the wiring part 3 can be formed in the magnetic layer 5. Therefore, the effective magnetic permeability around the wiring part 3 can be improved. As a result, the magnetic wiring circuit board 1 having a high inductance can be manufactured.

  Therefore, this manufacturing method can obtain the magnetic wiring circuit board 1 having a high inductance and an excellent insulating property of the second insulating layer 4.

  However, as shown in FIG. 2A, when the wiring portion 3 having a sharp portion is formed in the first step, the second insulating layer 4 facing the first sharp portion 25 is shown in the second step as shown in FIG. 9A. The thickness T1 is likely to be excessively thin. Thereafter, as shown in FIG. 9B, if the magnetic layer 5 is formed in the third step, the magnetic particles 18 come into contact with the wiring part 3, so that the insulation between the magnetic layer 5 and the wiring part 3 cannot be ensured.

  However, as shown in FIG. 2A, even if the wiring base 36 having the first sharpened portion 25 is formed in the fourth step, the first sharpened portion 25 is covered in the fifth step as shown in FIG. 2B. The plating layer 30 having the first covering portion 31 is formed, and the first corner portion 21 is formed in a substantially curved shape from the first covering portion 31. Therefore, as shown in FIG. 2C, in the second step, the second insulating layer 4 covering the first corner 21 is suppressed from being excessively thin, that is, the thickness T1 (enlarged view of FIG. 1). Reference).

  As shown in FIG. 2D, by forming the magnetic layer 5 in the third step, the magnetic particles 18 in the magnetic layer 5 are prevented from penetrating the second insulating layer 4 and coming into contact with the wiring portion 3. Can do.

<Modification>
In the following modifications, members and processes similar to those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Moreover, each modification can have the same operational effects as those of the embodiment, unless otherwise specified. Furthermore, one embodiment and its modification examples can be combined as appropriate.

  In one embodiment, the magnetic wiring circuit board 1 including the magnetic layer 5 is described as an example of the wiring circuit board of the present invention. However, although not illustrated, the present invention is not limited to this, and examples thereof include a printed circuit board including a particle-containing layer other than the magnetic layer 5.

  The particle-containing layer contains conductive particles other than the above-described magnetic particles in an appropriate ratio. The conductive particles are not particularly limited, and include metal particles such as copper particles, silver particles, gold particles, iron particles, and solder particles.

  In order to obtain a printed circuit board having a particle-containing layer, as shown in FIG. 2C, the above-described particle-containing sheet is prepared instead of the magnetic sheet 17, and the particle-containing sheet is heated to the printed circuit board preparation 6. Press.

  And in this wired circuit board, since the 1st corner | angular part 21 of the wiring part 3 has a substantially curved shape, it suppresses that the 2nd insulating layer 4 which coat | covers this 1st corner | angular part 21 becomes too thin. However, it can be formed. Therefore, it can suppress that electroconductive particle penetrates the 2nd insulating layer 4, and contacts the wiring part 3. FIG. As a result, the second insulating layer 4 can ensure insulation of the particle-containing layer with respect to the wiring portion 3.

  However, in the second step, when the particle-containing sheet is hot-pressed against the second insulating layer 4, the conductive particles contained in the particle-containing sheet contact the wiring through the second insulating layer 4. Easy to do.

  However, in this method for manufacturing a printed circuit board, the first corner portion 21 having a substantially curved shape is formed in the wiring portion 3 in the first step. Therefore, the second insulating layer 4 that covers the first corner portion 21 is formed. It can be formed thick.

  Therefore, penetration of the conductive particles into the second insulating layer 4 and contact of the conductive particles with the wiring portion 3 can be suppressed.

  Therefore, this manufacturing method can provide a printed circuit board in which the insulating property of the second insulating layer 4 is ensured.

  Therefore, this printed circuit board can ensure the insulation of the second insulating layer 4.

  As shown in FIG. 1, in one embodiment, a single wiring portion 3 has a constricted portion in which the length between two wiring side surfaces 11 is the shortest at the center portion in the first direction. However, as shown in FIG. 4, the wiring part 3 can also have the wiring side surface 11 which does not have a constriction part.

  Moreover, FIG. 1 in one Embodiment shows an example in which the thickness of the plating layer 30 is relatively thick. As shown in FIG. 4, this modification is an example in which the thickness of the plating layer 30 is thinner than that of the embodiment.

  In this modification, the radius of curvature R of the circle C forming the curved surface 23 is relatively small, and the center angle α is also small. The radius of curvature R is, for example, less than 9 μm, further 5 μm or less, further 2 μm or less, and the central angle α is less than 110 degrees.

  Although the curvature radius R in this modification is smaller than the curvature radius R of one embodiment, the second insulating layer 4 corresponding to the curved surface 23 can be formed with a sufficient thickness as in the first embodiment. .

  Moreover, as shown in FIG. 1, in one embodiment, the second corner portion 22 has an inclined surface 24 having a tapered surface 27. However, as shown in FIG. 5, the second corner portion 22 may have a vertical surface 33 formed perpendicular to the flat surface 26 instead of the inclined surface 24.

  The two vertical surfaces 33 facing each other have the same length as they go to the other side in the thickness direction.

  In addition, as shown in FIG. 6, the inclined surface 24 is replaced by a taper surface 27 that expands toward the outer side in the first direction as it goes toward the second wiring surface 10, and as it goes toward the first insulating surface 7. A second tapered surface (first constricted surface) 34 that constricts toward the inner side in the first direction can also be provided.

  Such a second tapered surface (first constricted surface) 34 is formed by, for example, an additive method.

  As shown in FIG. 1, in one embodiment, the inclined surface 24 includes only a tapered surface 27. However, as shown in FIG. 7, for example, the thickness direction other end edge of the inclined surface 24 may be the second curved surface 35. The second curved surfaces 35 adjacent to each other are second constricted surfaces 37 whose length decreases between the second curved surfaces 35 toward the first insulating surface 7. In this case, the wiring side surface 11 includes a portion of the curved surface 23 of the first corner portion 21 facing outward in the first direction, a central portion 50 in the thickness direction, a tapered surface 27 and a second constriction in the inclined surface 24. A surface 37 is provided continuously.

  In one embodiment, as shown in FIGS. 1A to 1B, the wiring portion 3 includes flat surfaces (for example, the first wiring surface 9 and the second wiring surface 10). In this modified example, the wiring portion 3 is illustrated in FIG. 8C. Thus, it has a substantially circular cross section that does not include a flat surface.

  Specifically, the wiring portion 3 has a substantially circular shape when cut in a cross section orthogonal to the direction of transmitting current (transmission direction) (the depth direction on the paper). The wiring part 3 has a wiring peripheral surface 46 that is an outer peripheral surface.

  The radius of the wiring part 3 is, for example, 25 μm or more, preferably 50 μm or more, and, for example, 2000 μm or less, preferably 200 μm or less.

  The second insulating layer 4 covers the wiring peripheral surface 37 of the wiring part 3. The second insulating layer 4 is formed with a uniform thickness along the first peripheral surface 37, and specifically has a substantially annular shape in cross section. The second insulating layer 4 has an inner peripheral surface that contacts the wiring peripheral surface 46 of the wiring part 3 and an insulating peripheral surface 47 that is an outer peripheral surface. The other edge in the thickness direction of the insulating peripheral surface 47 is in contact with the first insulating surface 7 of the first insulating layer 2.

  The thickness T of the second insulating layer 4 is the distance between the inner peripheral surface and the insulating peripheral surface 47, as disclosed in the embodiment.

  The magnetic layer 5 covers the wiring peripheral surface 46 of the wiring part 3 via the second insulating layer 4.

  In the magnetic layer 5, the magnetic particles 18 are oriented along the wiring peripheral surface 46 of the wiring part 3, specifically, the insulating peripheral surface 47 of the second insulating layer 4 in the vicinity of the second insulating layer 4. Yes. The region near the second insulating layer 4 is defined as a region within 1.5 times the radius of the wiring part 3, for example.

  As shown in FIG. 8A, in order to manufacture the magnetic wiring circuit board 1, first, the first insulating layer 2 is prepared. Separately, the wiring part 3 and the second insulating layer 4 are prepared. The wiring part 3 and the 2nd insulating layer 4 can be prepared as a commercially available enameled wire.

  Next, as shown in FIG. 8B, the other end in the thickness direction of the second insulating layer 4 is arranged on the first insulating surface 7 of the first insulating layer 2. Thereby, a 1st process and a 2nd process are implemented simultaneously.

  Then, the magnetic sheet 17 is hot-pressed with respect to the 1st insulating layer 2, the wiring part 3, and the 2nd insulating layer 4 (implementation of a 3rd process).

  Thereby, in the second insulating layer 4, the magnetic particles 18 are formed on the wiring peripheral surface 46 of the wiring part 3, specifically, the insulating peripheral surface 47 of the second insulating layer 4 in the vicinity of the second insulating layer 4. Orient along.

  Thereby, the magnetic wiring circuit board 1 including the first insulating layer 2, the wiring part 3, the second insulating layer 4, and the magnetic layer 5 is obtained.

  In the magnetic wiring circuit board 1, the magnetic particles 18 in the magnetic layer 5 around (in the vicinity of) the wiring portion 3 (second insulating layer 4) are the wiring peripheral surface 46, specifically, the insulating peripheral surface. A smooth magnetic path along 47 can be formed. Therefore, the effective magnetic permeability around the wiring part 3 can be improved. As a result, this magnetic wired circuit board 1 has a high inductance.

  In the method for manufacturing the magnetic wiring circuit board 1, in the third step, the magnetic particles 18 are substantially curved in the wiring portion 3 in the magnetic layer 5 around (in the vicinity of) the wiring portion 3 (second insulating layer 4). A smooth magnetic path along the shape can be formed. Therefore, the effective magnetic permeability around the wiring part 3 can be improved. As a result, the magnetic wiring circuit board 1 having a high inductance can be manufactured.

  The ratio of the magnetic particles 18 in the magnetic layer 5 may be uniform in the magnetic layer 5, and may increase or decrease as the distance from the wiring portions 3 increases.

  8A to 8C, the wiring portion 3 has a substantially circular cross section, but is not particularly limited as long as it has a substantially curved shape in cross-sectional view. For example, although not illustrated, It may be substantially rectangular or substantially trapezoidal with at least one curved corner. In this modification, the insulating layer 4 covers the entire surface of the wiring peripheral surface 46 of the wiring part 3 although not shown.

1 Magnetic circuit board (an example of a circuit board)
2 1st insulating layer 3 Wiring part (an example of wiring)
4 Second insulating layer 5 Magnetic layer (an example of a particle-containing layer)
7 First insulating surface 9 First wiring surface 10 Second wiring surface 11 Wiring side surface 16 Exposed surface 17 Magnetic sheet (an example of a particle-containing sheet)
18 Magnetic particle 21 First corner portion 22 Second corner portion 24 Inclined surface 25 Sharp portion 27 Tapered surface 30 Plating layer 31 First covering portion 36 Wiring base portion 46 Wiring peripheral surface 47 Insulating peripheral surface T Thickness of second insulating layer (average) Thickness)

Claims (13)

A first insulating layer;
Wiring disposed on one surface in the thickness direction of the first insulating layer;
A second insulating layer covering the wiring;
Containing conductive particles having a shape with an aspect ratio of 2 or more, and comprising a particle-containing layer covering the wiring via the second insulating layer;
The printed circuit board, wherein the wiring has a substantially curved shape. The conductive particles are magnetic particles;
The particle-containing layer is a magnetic layer;
The wired circuit board according to claim 1, wherein the printed circuit board is a magnetic wired circuit board.   The printed circuit board according to claim 2, wherein the second insulating layer is an electrodeposited layer.   4. The printed circuit board according to claim 2, wherein an average thickness T of the second insulating layer is 10 μm or less. 5. The wiring includes a thickness direction one surface disposed to be opposed to the one surface in the thickness direction of the first insulating layer with a space therebetween, a thickness direction other surface in contact with the one thickness direction surface of the first insulating layer, A side surface connecting both edges of the one surface in the thickness direction and the other surface in the thickness direction;
The second insulating layer covers the one surface in the thickness direction and the side surface,
The wiring has a corner formed by the one side surface and the side surface in the thickness direction;
The wired circuit board according to claim 2, wherein the corner portion has a substantially curved shape.   6. The printed circuit board according to claim 5, wherein a radius of curvature R of the corner is 9 [mu] m or more. The magnetic layer covers the one surface in the thickness direction exposed from the second insulating layer in the first insulating layer,
The wiring has a second corner formed by the other surface in the thickness direction and the side surface,
7. The printed circuit board according to claim 5, wherein the second corner portion has a portion in which a length between the two side surfaces facing each other becomes longer as approaching the other side in the thickness direction. 8. The wiring has a substantially circular shape,
The second insulating layer covers a peripheral surface of the wiring;
5. The printed circuit board according to claim 2, wherein the particle-containing layer covers the peripheral surface of the wiring via the second insulating layer. 6. A first step of preparing a first insulating layer and a wiring disposed on one surface in the thickness direction of the first insulating layer;
A second step of covering the wiring with a second insulating layer;
And a third step of forming a particle-containing layer containing conductive particles having a shape with an aspect ratio of 2 or more, covering the wiring via the second insulating layer,
The wiring forms a substantially curved shape,
In the second step, the particle-containing sheet containing the conductive particles oriented in a direction orthogonal to the thickness direction is hot-pressed on the second insulating layer. Production method. The conductive particles are magnetic particles;
The particle-containing layer is a magnetic layer;
The particle-containing sheet is a magnetic sheet,
The method for manufacturing a printed circuit board according to claim 9, wherein the method is a method for manufacturing a magnetic printed circuit board. The wiring in the first step has a thickness in contact with the one surface in the thickness direction of the first insulating layer and the one surface in the thickness direction of the first insulating layer facing each other with a space therebetween. The other side surface in the thickness direction, and the side surface connecting the both end edges of the one surface in the thickness direction and the other surface in the thickness direction, and corner portions having a substantially curved shape are formed on the one surface in the thickness direction and the side surface. And
In the second step, the insulating layer covers the one surface in the thickness direction and the side surface of the wiring,
11. The wired circuit board according to claim 10, wherein in the third step, a particle-containing layer that covers the one surface in the thickness direction and the side surface of the wiring is formed via the second insulating layer. Manufacturing method. The first step includes
A fourth step of forming a wiring base having a pointed portion formed by one surface and a side surface in the thickness direction by a subtractive method; and
By forming the plating layer covering the wiring base by plating and having the covering portion covering the sharp portion, the corner portion is formed in a substantially curved shape from the covering portion. The method for manufacturing a printed circuit board according to claim 11, comprising five steps. The wiring in the first step has a substantially circular shape,
In the second step, the insulating layer covers a peripheral surface of the wiring,
The method for manufacturing a printed circuit board according to claim 10, wherein in the third step, a particle-containing layer that covers the peripheral surface of the wiring is formed via the second insulating layer.

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