JP2019160919A - Method of manufacturing wiring board - Google Patents

Abstract

To provide a method of manufacturing a wiring board capable of suppressing exposure of a wiring unit, excellent in productivity, and capable of facilitating miniaturization of a wiring pattern.SOLUTION: The method of manufacturing a wiring board includes: a preparation step of preparing a laminate including a base insulating layer 2 having a through hole 6, and a metal sheet disposed on the base insulating layer 2; a wiring formation step of forming a wiring pattern 3 by a subtractive method so as to overlap with the through hole 6 when projected in a thickness direction; and an electrodeposition step of covering the wiring pattern 3 with a first magnetic layer 5 by supplying power for electrodeposition through the through hole 6.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a wiring board.

  An inductor, which is an example of a wiring board, is known to be mounted on an electronic device or the like and used as a passive element such as a voltage conversion member.

  For example, a flexible inductor is proposed in which an anisotropic composite magnetic sheet obtained by dispersing a flat or needle-like soft magnetic metal powder in a resin material is laminated on the upper and / or lower surface of a coil. (For example, refer to Patent Document 1).

JP 2009-9985 A

  By the way, in the inductor of Patent Document 1, the anisotropic composite magnetic sheet is in direct contact with the coil. Therefore, there is a problem that a plurality of adjacent wiring parts constituting the coil are short-circuited via a large number of soft magnetic metal powders in the anisotropic composite magnetic sheet.

  Therefore, before laminating the anisotropic composite magnetic sheet on a plurality of wiring portions, it is considered to cover the wiring portions with a cover insulating layer (electrodeposition coating film) using electrodeposition coating. Specifically, in this configuration, for example, a step of forming a wiring pattern 41 having a plurality of wiring portions and a lead wire 42 that enables power supply from the outside on the insulating base layer 40, the lead wire 42. B process for protecting the mask with the masking tape 43, supplying power for electrodeposition coating via the lead wire 42, c process for covering the wiring pattern 41 with the cover insulating layer 44, removing the masking tape 43, The d process for exposing the lead wire 42, the e process for removing the lead wire 42 by etching, and the f process for laminating the magnetic layer 45 on the wiring pattern 41 covered with the cover insulating layer 44 can be manufactured (FIG. 9A to FIG. 10F).

  However, in this manufacturing method, the side surface of the end portion of the wiring pattern 41 connected to the lead wire 42 is exposed after the step e. That is, an exposed surface 46 that is not covered with the insulating cover layer 44 is generated in the wiring pattern 41. In such a case, the magnetic layer 45 contacts the exposed surface 46 after the step f. As a result, a current flowing through the wiring pattern flows to the magnetic layer 45 via the exposed surface 46, which causes a problem that a function as a wiring such as a coil is deteriorated.

  Further, in an inductor that is often arranged near the power supply, it is necessary to allow a large current to flow by increasing the thickness of the wiring portion. However, if the wiring portion is formed to be thicker by the additive method, it takes a lot of time and the productivity is poor. On the other hand, when a commercially available wiring such as a winding is used, it is difficult to miniaturize the wiring pattern, and the design freedom of the wiring pattern is greatly reduced.

  The present invention provides a method of manufacturing a wiring board that can suppress exposure of a wiring part, is excellent in productivity, and facilitates miniaturization of a wiring pattern.

  The present invention [1] includes a preparation step of preparing a laminate including an insulating layer having a through hole and a metal layer disposed on one side in the thickness direction of the insulating layer, and the penetration when projected in the thickness direction. A wiring formation step of forming a wiring pattern by a subtractive method so as to overlap the hole, and an electrodeposition step of covering the wiring pattern with a protective layer by supplying power for electrodeposition through the through hole. A method for manufacturing a wiring board is provided.

  In this wiring board manufacturing method, since the wiring pattern is formed by the subtractive method, a relatively thick wiring pattern can be formed in a short time, and the productivity is excellent. In addition, the wiring pattern can be easily miniaturized and the degree of freedom in design is high.

  Further, in this wiring board manufacturing method, the protective layer is covered with the wiring pattern by supplying power for electrodeposition through the through hole, so that one side surface and the side surface in the thickness direction of the wiring pattern are covered with the protective layer. And the exposure of the wiring pattern can be suppressed.

  The present invention [2] includes a conductor layer arranging step of arranging a conductor layer on the other side in the thickness direction of the insulating layer before the wiring forming step, and a conductor layer removing step of removing the conductor layer after the electrodeposition step. The method for manufacturing a wiring board according to [1], further comprising:

  In this method of manufacturing a wiring board, the conductor layer is disposed on the other side in the thickness direction of the insulating layer, so that power can be supplied to the wiring portion through the conductor layer and the through hole. Therefore, the wiring part can be easily covered with the protective layer.

  This invention [3] is further provided with the functional layer arrangement | positioning process which arrange | positions a functional layer to the thickness direction one side of the said insulating layer and the said protective layer after an electrodeposition process, The wiring as described in [1] or [2] A method for manufacturing a substrate is included.

  In this method of manufacturing a wiring board, a functional layer is disposed on the wiring board, so that a desired function can be imparted to the wiring board.

  This invention [4] includes the manufacturing method of the wiring board as described in any one of [1]-[3] whose said protective layer is an electrodeposition coating film.

  In this method of manufacturing a wiring board, the protective layer is an electrodeposition coating film, so that the wiring pattern is covered with an insulator. Therefore, when a conductive functional layer is disposed on one side in the thickness direction of the wiring pattern, a short circuit of the wiring pattern can be suppressed.

  The method for manufacturing a wiring board according to the present invention can suppress the exposure of the wiring portion. Moreover, it is excellent in productivity, and the degree of freedom in designing and miniaturizing the wiring pattern is easy.

FIG. 1 shows a plan view of a first embodiment of an inductor of the present invention. 2A and 2B are cross-sectional views of FIG. 1, FIG. 2A is a cross-sectional view taken along the line AA, and FIG. 2B is a cross-sectional view taken along the line BB. 3A to 3F are cross-sectional views of the manufacturing process of the inductor shown in FIG. 1 (A-A cross-sectional view of FIG. 1), FIG. 3A is a step of preparing a metal sheet, and FIG. 3B is a base insulating layer. Step of placing, FIG. 3C shows a step of placing a metal thin film, FIG. 3D shows a step of placing a support film, FIG. 3E shows a step of forming a wiring pattern, and FIG. 3F shows a step of performing electrodeposition. 4G to 4J are cross-sectional views of the inductor manufacturing process subsequent to FIG. 3 (A-A cross-sectional view of FIG. 1), FIG. 4G is a process of disposing the first magnetic layer, and FIG. 4H is a support film. FIG. 4I shows the step of removing the metal thin film, and FIG. 4J shows the step of disposing the adhesive layer and the second magnetic layer. 5A to 5F are sectional views (sectional view taken along line BB in FIG. 1) of the manufacturing process of the inductor shown in FIG. 1, FIG. 5A is a step of preparing a metal sheet, and FIG. Step of placing, FIG. 5C shows a step of placing a metal thin film, FIG. 5D shows a step of placing a support film, FIG. 5E shows a step of forming a wiring pattern, and FIG. 5F shows a step of performing electrodeposition. 6G to 6J are sectional views (sectional view taken along the line BB in FIG. 1) of the inductor manufacturing process subsequent to FIG. 5, FIG. 6G is a process of arranging the first magnetic layer, and FIG. 6H is a support film. FIG. 6I shows the step of removing the metal thin film, and FIG. 6J shows the step of disposing the adhesive layer and the second magnetic layer. FIG. 7 shows a cross-sectional view of the usage pattern of the inductor shown in FIG. 8A and 8B are a first modification of the inductor manufacturing method according to the first embodiment (a method of disposing a cover metal layer), FIG. 8A is a process cross-sectional view of disposing a cover metal layer, and FIG. FIG. 8A shows a plan view of FIG. 8A. 9A to 9C are a plan view and a cross-sectional view of the manufacturing process of the inductor of the reference example, FIG. 9A is a process for forming the wiring portion and the lead wire, and FIG. 9B is a process b for masking the electrodeposited lead. FIG. 9C shows step c for performing electrodeposition. 10D to 10F are a plan view and a cross-sectional view of the inductor manufacturing process subsequent to FIG. 9, FIG. 10D is a d process for removing the masking sheet, FIG. 10E is an e process for removing the electrodeposited lead, and FIG. 10F shows the f process which arrange | positions a magnetic layer.

  In FIG. 1, the vertical direction of the paper surface is the front-back direction (first direction), the lower side of the paper surface is the front side (one side in the first direction), and the upper side of the paper surface is the rear side (the other side in the first direction). The left-right direction on the paper surface is the left-right direction (second direction orthogonal to the first direction), the left side of the paper surface is the left side (second side in the second direction), and the right side of the paper surface is the right side (the other side in the second direction). The paper thickness direction is the vertical direction (thickness direction, third direction orthogonal to the first direction and the second direction), the front side of the paper is the upper side (one side in the thickness direction, the third direction one side), and the back side of the paper is The lower side (the other side in the thickness direction, the other side in the third direction). Specifically, it conforms to the direction arrow in each figure.

<First Embodiment>
A first embodiment of a method for manufacturing an inductor 1 will be described with reference to FIGS. 1 to 7 as an example of a method for manufacturing a wiring board according to the present invention.

  The first embodiment of the method for manufacturing the inductor 1 is a method for manufacturing the inductor 1 shown in FIGS. 1 to 2B, and includes a preparation step, a conductor layer placement step, a wiring formation step, an electrodeposition step, A magnetic layer arranging step, a conductor layer removing step, and a second magnetic layer arranging step are sequentially provided. Hereinafter, each process is explained in full detail.

(Preparation process)
In the preparation step, a laminated body 8 including a base insulating layer 2 as an example of an insulating layer and a metal sheet 10 as an example of a metal layer is prepared. Specifically, a laminate 8 including a base insulating layer 2 having a through hole 6 and a metal sheet 10 disposed below the base insulating layer 2 is prepared.

  First, as shown in FIGS. 3A and 5A, a metal sheet 10 is prepared.

  The metal sheet 10 is a member that becomes a wiring pattern 3 to be described later in the wiring forming process. That is, the metal sheet 10 is a raw material for the wiring pattern 3. The metal sheet 10 has a sheet shape extending in the front-rear direction and the left-right direction.

  Examples of the material of the metal sheet 10 include copper, silver, gold, nickel, or an alloy containing them. The material of the metal sheet 10 is preferably copper. Thereby, the inductor 1 provided with favorable electroconductivity and patterning property can be manufactured.

  The thickness of the metal sheet 10 is 25 micrometers or more, for example, Preferably, it is 50 micrometers or more, for example, is 300 micrometers or less, Preferably, it is 150 micrometers or less. Thereby, the inductor 1 which flows a large current can be manufactured.

  Next, as shown in FIGS. 3B and 5B, the base insulating layer 2 having the through holes 6 is disposed on the lower side of the metal sheet 10. That is, the base insulating layer 2 having a plurality of through holes 6 and a plurality of alignment marks 7 (positioning portions) is formed on the lower surface (the other surface in the thickness direction) of the metal sheet 10.

  Specifically, first, a varnish of a photosensitive insulating material is prepared, and this varnish is applied to the entire lower surface of the metal sheet 10 and dried to form a base film. The base film is exposed through a photomask having a pattern corresponding to the through hole 6 and the alignment mark 7. Thereafter, the base film is developed and cured by heating if necessary.

  Examples of the insulating material of the base insulating layer 2 include organic materials such as polyimide, polysiloxane, epoxy resin, and fluorine resin. Preferably, polyimide is used.

  As shown in FIG. 1, the through hole 6 is formed in the base insulating layer 2 at a position overlapping with the wiring portion 21 (described later) when projected in the thickness direction. The through-hole 6 has a substantially circular shape in plan view and a substantially rectangular shape in sectional view. The length (width) and the length in the front-rear direction of the through hole 6 are shorter than the length (width) and the length in the front-rear direction of the wiring part 21, respectively.

  The alignment mark 7 is an insulating portion formed by a mark hole 11 penetrating the insulating base layer 2 in the thickness direction. The alignment mark 7 is formed on the insulating base layer 2 at a position that does not overlap with the wiring pattern 3 when projected in the thickness direction. The alignment mark 7 has a substantially circular shape in plan view and a substantially rectangular shape in sectional view.

  Thereby, the base insulating layer 2 having the through holes 6 and the alignment marks 7 is formed on the lower surface of the metal sheet 10.

  Further, in the preparation step, as shown by the phantom line in FIG. 3A, a two-layer substrate including the metal sheet 10 and the base insulating layer 2 (that is, the base insulating layer having no holes) disposed on the entire lower surface thereof. Then, holes (through holes 6 and alignment marks 7) can be formed in the base insulating layer 2. In forming the hole, an etching resist having a pattern corresponding to the through hole 6 and the alignment mark 7 is disposed on the lower surface of the base insulating layer 2, and after etching the base insulating layer 2, the etching resist is removed. Alternatively, the through hole 6 and the alignment mark 7 are formed in the base insulating layer 2 using a laser.

(Conductor layer placement process)
In the conductor layer forming step, as shown in FIGS. 3C and 5C, a metal thin film 12 as an example of a conductor layer is disposed below the insulating base layer 2. That is, the metal thin film 12 is formed on the entire lower surface of the base insulating layer 2.

  In the arrangement of the metal thin film 12, the metal thin film 12 is formed so that the upper surface (one surface in the thickness direction) of the metal thin film 12 is in contact with the lower surface of the metal sheet 10 in the through hole 6 and the alignment mark 7. Specifically, the surface (first exposed surface 13) of the metal sheet 10 exposed from the through hole 6, the surface (second exposed surface 14) of the metal sheet 10 exposed from the mark hole 11, and the base insulation. A metal thin film 12 is formed so as to cover the lower surface of the layer 2.

  Examples of the method for disposing the metal thin film 12 include dry methods such as sputtering, vacuum deposition, and ion plating, and wet methods such as electroless plating (electroless copper plating, electroless nickel plating, etc.). Preferably, a dry method is mentioned, More preferably, a sputtering method is mentioned. Thereby, a uniform thin film (specifically, a sputtered film) having good adhesion can be reliably disposed on the first exposed surface 13 and the second exposed surface 14. In addition, the metal thin film 12 can be selectively removed with certainty in a removing step described later.

  The material of the metal thin film 12 is a metal material that can selectively remove the metal thin film 12 in a removing process described later, and examples thereof include metals such as copper, chromium, and nichrome.

  The thickness of the metal thin film 12 is, for example, 10 nm or more, preferably 30 nm or more, and for example, 200 nm or less, preferably 100 nm or less.

(Wiring formation process)
In the wiring formation step, the wiring pattern 3 is formed by subtractive so as to overlap the through hole 6. That is, the subtractive method is performed to remove unnecessary portions from the metal sheet 10 to form the wiring pattern 3.

  First, as shown in FIGS. 3D and 5D, the support film 15 is disposed on the lower surface of the metal thin film 12.

  As the support film 15, for example, a separator film having slight adhesiveness that can be easily peeled off from the metal thin film 12 in a later step is used. The arrangement of the support film 15 can reliably support the metal sheet 10 and the base insulating layer 2 and can prevent the cover insulating layer 4 from being coated on the lower surface of the metal thin film 12 in the electrodeposition process described later.

  Next, as shown in FIGS. 3E and 5E, a subtractive method is performed. Specifically, a dry film resist 16 (see virtual line) having a pattern corresponding to the wiring pattern 3 (described later) is disposed on the metal sheet 10, and then an unnecessary metal sheet 10 other than the wiring pattern 3 is attached. The dry film resist 16 is finally removed by etching or peeling.

  In the method of disposing the dry film resist 16 having a pattern, the dry film resist 16 is disposed on the entire upper surface of the metal sheet 10, exposed and developed through a photomask having a pattern corresponding to the wiring pattern 3, and heated and cured as necessary. Let

  At this time, by recognizing the alignment mark 7 with a detection device from the lower side, the dry film resist 16 remains so that the dry film resist 16 having a pattern remains at a position overlapping the through hole 6 when projected in the thickness direction. 16 is exposed and developed.

  Examples of the etching include wet etching such as chemical etching. In the case of wet etching, the upper part of the metal sheet 10 is more easily etched than the lower part, so that the wiring pattern 3 has a tapered shape in which a side sectional view shape extends downward.

  Thereby, the to-be-adhered body 17 provided with the support film 15, the metal thin film 12, the base insulating layer 2, and the wiring pattern 3 in order is obtained.

(Electrodeposition process)
In the electrodeposition process, as shown in FIGS. 3F and 5F, the wiring pattern 3 is covered with a cover insulating layer 4 as an example of a protective layer by electrodeposition. That is, the cover insulating layer 4 made of an electrodeposition coating film is formed on the upper surface and side surfaces of the wiring pattern 3 by electrodeposition coating.

  Specifically, the electrodeposition 17 is immersed in the electrodeposition paint-containing liquid, and then an electric current is applied to the electrodeposition 17 to deposit the electrodeposition paint on the surface of the wiring pattern 3. Then, the deposited electrodeposition paint is dried. Thereby, the electrodeposition coating film (that is, the cover insulating layer 4) formed from the electrodeposition paint is coated on the surface (upper surface and side surface) of the wiring pattern 3.

  Examples of the electrodeposition paint (that is, the insulating material of the cover insulating layer 4) include resins that are ionic in water and known or commercially available, such as acrylic resins, epoxy resins, Examples thereof include a polyimide resin or a mixture thereof.

  In order to apply a current to the electrodeposit 17, a lead wire (not shown) connected to an external power source is connected to the metal thin film 12. As a result, a direct current is applied from the first exposed surface 13 to the entire wiring pattern 3 via the lead wire and the metal thin film 12.

  As the electrodeposition coating, either an anionic electrodeposition coating that employs the electrodeposited body 17 (specifically, the wiring pattern 3) as a cathode, or a cation type electrodeposition coating that employs the electrodeposited body 17 as an anode. There may be.

  The drying temperature of the electrodeposition paint is, for example, 90 ° C. or more and 150 ° C. or less, and the drying time is, for example, 1 minute or more and 30 minutes or less.

  Thereby, the cover insulating layer 4 (electrodeposition coating film) is formed on the upper surface and the side surface of the wiring pattern 3.

  If necessary, the surface of the wiring pattern 3 is cleaned by degreasing and pickling before electrodeposition. If necessary, the electrodeposition paint is heat-cured by baking after electrodeposition. The heating temperature at the time of baking is, for example, 150 ° C. or more and 250 ° C. or less, and the heating time is, for example, 10 minutes or more and 5 hours or less.

(First magnetic layer arranging step)
In the first magnetic layer arranging step (an example of the functional layer arranging step), as shown in FIGS. 4G and 6G, the first magnetic layer 5 as an example of the functional layer is formed above the base insulating layer 2 and the cover insulating layer 4. Place. That is, the first magnetic layer 5 is laminated on the upper surface and side surfaces of the insulating cover layer 4 and the upper surface of the insulating base layer 2 exposed from the insulating cover layer 4 so as to cover the upper surface and side surfaces thereof.

  Examples of the material of the first magnetic layer 5 include a magnetic composition (preferably a soft magnetic composition) disclosed in JP 2014-189015 A and the like. Specifically, the material of the first magnetic layer 5 includes magnetic particles (preferably soft magnetic particles such as an Fe-Si-A1 alloy) and a resin (preferably a thermosetting resin such as an epoxy resin, Phenolic resin etc.).

  In order to dispose the first magnetic layer 5, for example, a semi-cured magnetic sheet formed from a magnetic composition is pressed against the upper surfaces of the base insulating layer 2 and the cover insulating layer 4, and thereafter or simultaneously with the pressing, The semi-cured magnetic sheet is cured by heating. For details, refer to JP2014-189015A.

  Thereby, the first magnetic layer 5 is disposed on the upper surfaces of the base insulating layer 2 and the cover insulating layer 4.

(Conductor layer removal process)
In the conductor layer removing step, the metal thin film 12 (conductor layer) is removed.

  First, as shown in FIGS. 4H and 6H, the support film 15 is removed from the metal thin film 12 by peeling.

  Next, the metal thin film 12 is removed from the base insulating layer 2 by etching or peeling as shown in FIGS. 4I and 6I. Preferably, the metal thin film 12 is removed by etching. Examples of the etching include the above-described wet etching.

  In the case where the metal thin film 12 is removed by etching, the first magnetic layer 5 is protected before the etching so as to protect the first magnetic layer 5 as necessary, as indicated by the phantom lines in FIGS. 4H and 6H. A protective sheet (masking sheet or the like) 28 is disposed on the entire upper surface of the substrate, and the protective sheet 28 is removed after etching.

  Thereby, the lower surface of the base insulating layer 2, the first exposed surface 13 and the second exposed surface 14 are exposed.

(Second magnetic layer arranging step)
In the second magnetic layer arranging step, the second magnetic layer 18 is arranged below the base insulating layer 2 as shown in FIGS. 4J and 6J. That is, the second magnetic layer 18 is laminated on the lower surface of the base insulating layer 2 via the adhesive layer 19.

  First, the adhesive layer 19 is disposed on the upper surface of the second magnetic layer 18 to prepare a laminate of the adhesive layer 19 and the second magnetic layer 18.

  The material of the second magnetic layer 18 is the same as the material of the first magnetic layer 5. The second magnetic layer 18 can be produced by the method exemplified for the first magnetic layer 5.

  Examples of the material for the adhesive layer 19 include known or commercially available adhesive compositions and pressure-sensitive adhesive compositions, such as acrylic compositions, epoxy compositions, rubber compositions, and silicone compositions. It is done.

  Examples of the arrangement of the adhesive layer 19 include a method of applying an adhesive composition to the second magnetic layer 18 and a method of pressing an adhesive tape against the second magnetic layer 18.

  Next, the laminate of the adhesive layer 19 and the second magnetic layer 18 is disposed on the lower surface of the base insulating layer 2 so that the adhesive layer 19 and the base insulating layer 2 are in contact with each other. At this time, the adhesive layer 19 is disposed on the lower surface of the base insulating layer 2 so that the insides of the through holes 6 and the mark holes 11 are filled with the adhesive layer 19.

  In the second magnetic layer arranging step, the adhesive layer 19 is arranged on the lower surface of the base insulating layer 2 by coating or the like from the viewpoint of good filling of the adhesive layer 19 into the holes, and then the second magnetic layer 18 can also be placed on the underside of the adhesive layer 19. On the other hand, from the viewpoint of productivity, as described above, a laminated body of the adhesive layer 19 and the second magnetic layer 18 is prepared and disposed on the lower surface of the base insulating layer 2.

  Thereby, the inductor 1 is obtained.

(Inductor)
As shown in FIG. 1, the inductor 1 has a substantially rectangular sheet shape extending in the front-rear direction and the left-right direction. 2A-B, the inductor 1 includes a second magnetic layer 18, an adhesive layer 19, a base insulating layer 2, a wiring pattern 3, a cover insulating layer 4, and a first magnetic layer 5. Provide in this order in the thickness direction.

  The second magnetic layer 18 is a layer that imparts high inductance to the inductor 1. The second magnetic layer 18 is the lowest layer in the inductor 1. The second magnetic layer 18 has substantially the same shape as the base insulating layer 2 in plan view, and has a sheet shape extending in the front-rear direction and the left-right direction.

  The thickness of the 2nd magnetic layer 18 is 10 micrometers or more, for example, Preferably, it is 50 micrometers or more, for example, is 500 micrometers or less, Preferably, it is 300 micrometers or less.

  The adhesive layer 19 is a layer that bonds the second magnetic layer 18 and the base insulating layer 2 together. The adhesive layer 19 is disposed on the upper surface of the second magnetic layer 18. Specifically, the adhesive layer 19 is disposed between the second magnetic layer 18 and the base insulating layer 2 so as to be in contact with the upper surface of the second magnetic layer 18 and the lower surface of the base insulating layer 2. .

  The adhesive layer 19 is filled in the through holes 6 and the mark holes 11 in the base insulating layer 2. That is, the upper surface of the adhesive layer 19 is in contact with the first exposed surface 13 of the wiring pattern 3 and the second exposed surface 14 of the first magnetic layer 5.

  The thickness (maximum thickness) of the adhesive layer 19 is, for example, 0.5 μm or more, preferably 1 μm or more, and for example, 10 μm or less, preferably 5 μm or less.

  The base insulating layer 2 is a layer that supports the wiring pattern 3. The base insulating layer 2 is disposed on the upper surface of the adhesive layer 19. A wiring pattern 3, a cover insulating layer 4, and a first magnetic layer 5 are disposed on the upper surface of the base insulating layer 2. The base insulating layer 2 has a sheet shape that is the same outer shape as the inductor 1. The base insulating layer 2 includes a through hole 6 and an alignment mark 7.

  The thickness of the base insulating layer 2 is, for example, 0.1 μm or more, preferably 1 μm or more, and for example, 15 μm or less, preferably 5 μm or less. If the thickness of the base insulating layer 2 is in the above range, the inductor 1 can be made thin while maintaining the mechanical strength of the inductance.

  The wiring pattern 3 is disposed on the upper surface of the base insulating layer 2. The wiring pattern 3 has a substantially rectangular loop shape in plan view.

  The wiring pattern 3 includes a plurality (two) of wiring portions 21 extending in the front-rear direction, a connection wiring portion 22 that connects the front ends of the plurality of wiring portions 21, and a plurality ( Two) terminal portions 23 are integrally provided.

  The plurality of wiring sections 21 include a first wiring section 21a and a second wiring section 21b that are arranged at intervals in the left-right direction (an example of a predetermined direction). Each of the plurality of wiring portions 21 has a substantially rectangular shape that extends in the front-rear direction in a plan view, and a substantially trapezoidal shape that has a tapered shape that extends downward in a side sectional view.

  The wiring pattern 3, in particular, the first wiring portion 21 a and the second wiring portion 21 b are disposed on the upper surface of the common base insulating layer 2. That is, the base insulating layer 2 that supports the first wiring portion 21a and the base insulating layer 2 that supports the second wiring portion 21b are continuous with each other.

  The connection wiring part 22 is arrange | positioned in front of the 1st wiring part 21a and the 2nd wiring part 21b, and connects these front ends mutually. That is, the rear end edge of the left end portion of the connection wiring portion 22 is continuous with the front end edge of the first wiring portion 21a, and the front end edge of the right end portion of the connection wiring portion 22 is continuous with the front end edge of the second wiring portion 21b. . The connection wiring portion 22 has a substantially rectangular shape extending in the left-right direction in a plan view, and has a substantially trapezoidal shape having a tapered shape that expands downward in a side sectional view.

  A plurality (two) of terminal portions 23 are arranged at the rear end of the first wiring portion 21a and the rear end of the second wiring portion 21b so as to be continuous therewith. The length (width) in the left-right direction of the plurality of terminal portions 23 is shorter than the length (width) in the left-right direction of the wiring portion 21. The terminal part 23 has a substantially rectangular shape in plan view, and has a substantially trapezoidal shape having a tapered shape that expands downward in a side sectional view.

  The width (length in the left-right direction) of the wiring part 21 and the width (length in the front-rear direction) of the connection wiring part 22 are, for example, 25 μm or more, preferably 100 μm or more, and for example, 2000 μm or less, preferably 750 μm or less.

  The thickness of the wiring pattern 3 is the same as the thickness of the metal sheet 10 described above.

  The material of the wiring pattern 3 is the same as the material of the metal sheet 10, and preferably copper. If the wiring pattern 3 is a copper wiring formed of copper, since copper has good conductivity and patterning properties, the inductor 1 having good conductivity and fine patterning can be easily manufactured.

  The insulating cover layer 4 is an insulating layer that protects the wiring pattern 3. The insulating cover layer 4 is disposed on the insulating base layer 2 so as to cover the entire upper surface and side surfaces of the wiring pattern 3.

  The cover insulating layer 4 includes a first cover insulating portion 4a that covers the first wiring portion 21a, a second cover insulating portion 4b that covers the second wiring portion 21b, and a third cover insulating portion that covers the connection wiring portion 22. 4c and a plurality (two) of fourth cover insulating portions 4d that cover the plurality (two) of terminal portions 23 are integrally provided.

  In the cover insulating layer 4, the left fourth cover insulating portion 4d, the first cover insulating portion 4a, the third cover insulating portion 4c, the second cover insulating portion 4b, and the right fourth cover insulating portion 4d are arranged in this order. Continuous in the direction or front-rear direction.

  2A, in the cover insulating layer 4, the first cover insulating portion 4a and the second cover insulating portion 4b are not directly connected to each other. That is, the insulating cover layer 4 is not formed so as to continue between the plurality of wiring portions 21 (the first wiring portion 21a and the second wiring portion 21b) adjacent to each other in the left-right direction. More specifically, the insulating cover layer 4 is not substantially present between the plurality of wiring portions 24 (however, the insulating cover layer 4 (4a, 4b) covering the side surface of the wiring portion 21 is excluded).

  The thickness of the insulating cover 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. Thereby, the distance between the wiring pattern 3 and the first magnetic layer 5 can be made closer while the wiring pattern 3 and the first magnetic layer 5 are in contact with each other. Therefore, the inductance of the inductor 1 can be further improved.

  The first magnetic layer 5 is a layer that imparts high inductance to the inductor 1. The first magnetic layer 5 has substantially the same shape as the base insulating layer 2 in plan view, and has a sheet shape extending in the front-rear direction and the left-right direction.

  The first magnetic layer 5 is the uppermost layer in the inductor 1. The first magnetic layer 5 is disposed on the base insulating layer 2 and the cover insulating layer 4. Specifically, the first magnetic layer 5 is disposed on the upper surface of the base insulating layer 2 so as to cover the upper surface and side surfaces of the insulating cover layer 4.

  The first magnetic layer 5 exists over the entire vertical direction of the wiring portion 21 between the wiring portions 24. In other words, the first magnetic layer 5 exists from the upper surface of the base insulating layer 2 to a position higher than the wiring portion 21 in the wiring portion 24. Further, the first magnetic layer 5 substantially fills the entire wiring portion 24. Specifically, the wiring portion 21 (the first wiring portion 21a and the second wiring portion 21b) and the cover insulating layer 4 (the first cover insulating portion 4a and the second cover insulating portion 4b) covering the wiring portion 21 are configured. When the member is a cover wiring part, only the first magnetic layer 5 exists between the cover wiring parts adjacent to each other in a side sectional view.

  The thickness of the 1st magnetic layer 5 is 10 micrometers or more, for example, Preferably, it is 50 micrometers or more, for example, is 500 micrometers or less, Preferably, it is 300 micrometers or less.

  The inductor 1 is not an electronic device to be described later, but is a component of the electronic device, that is, a component for manufacturing the electronic device, and does not include an electronic element (chip, capacitor, etc.) or a mounting substrate on which the electronic element is mounted. It is a device that can be distributed industrially and used by industry.

  For example, the inductor 1 is mounted (embedded) in an electronic device or the like. Although not shown, the electronic device includes a mounting substrate and electronic elements (chip, capacitor, etc.) mounted on the mounting substrate. In the electronic device, the inductor 1 is mounted on a mounting board. Specifically, as shown in FIG. 7, a plurality of vias 25 (through holes) penetrating the first magnetic layer 5 and the cover insulating layer 4 in the thickness direction are formed so that the terminal portions 23 are exposed. An insulation treatment is performed on the inner peripheral surface of 25. Next, the conductive connection member 26 is disposed inside the via 25 so that one end of the connection member 26 is in contact with the upper surface of the terminal portion 23. The inductor 1 is mounted on the mounting substrate via the connection member 26, is electrically connected to other electronic devices, and functions as a passive element.

  And in the manufacturing method of this inductor 1, the preparation process which prepares the laminated body 8 provided with the base insulating layer 2 which has the through-hole 6, and the metal sheet 10 arrange | positioned above the base insulating layer 2, and the thickness direction A wiring forming process for forming the wiring pattern 3 by a subtractive method so as to overlap with the through hole 6 when projected, and supplying power for electrodeposition through the through hole 6, thereby making the wiring pattern 3 have a first magnetic property. An electrodeposition step of covering with the layer 5.

  In this manufacturing method, the wiring pattern 3 is formed by a subtractive method. That is, the wiring pattern 3 can be formed from the metal sheet 10 by etching. For this reason, the relatively thick wiring pattern 3 can be formed in a short time, and the productivity is excellent. Further, the wiring pattern 3 can be easily miniaturized, and the design freedom of the wiring pattern 3 is high.

  Further, the insulating cover layer 4 is covered with the wiring pattern 3 by supplying power through the through hole 6 on the back side of the wiring pattern 3. For this reason, the entire upper surface and side surfaces of the wiring pattern 3 can be covered with the insulating cover layer 4 (electrodeposition coating film), and the exposure of the wiring pattern 3 can be suppressed. That is, the exposed surface 46 shown in FIG. 10F does not occur. Therefore, even when the first magnetic layer 5 is further disposed on the upper side of the wiring pattern 3 covered with the insulating cover layer 4, it is possible to suppress the first magnetic layer 5 from directly contacting the wiring pattern 3. As a result, a short circuit of the wiring pattern 3 can be suppressed. Furthermore, since the insulating cover layer 4 is covered by electrodeposition coating, the insulating cover layer 4 can be covered thinly and uniformly on the surface of the wiring pattern 3.

  In addition, this manufacturing method includes a conductor layer disposing step for disposing the metal thin film 12 below the insulating base layer 2 before the wiring forming step, and a conductor layer removing step for removing the metal thin film 12 after the electrodeposition step. Is provided.

  For this reason, power can be supplied to the wiring part 21 through the metal thin film 12 and the through hole 6. That is, since it suffices to supply power to the metal thin film 12 spreading on the lower surface of the base insulating layer 2, power supply to the wiring portion 21 is easy. Therefore, the wiring part 21 can be easily covered.

  In addition, this manufacturing method includes a functional layer arranging step of arranging the first magnetic layer 5 on the upper side of the insulating base layer 2 and the insulating cover layer 4 after the electrodeposition step.

  For this reason, the inductor 1 can be provided with a high inductance function.

(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 be combined suitably. Furthermore, each modification can produce the same effects as those of the above-described embodiment, unless otherwise specified.

First Modification In the electrodeposition process of the above embodiment, as shown in FIGS. 3F and 5F, the cover insulating layer 4 as an example of a protective layer is formed on the upper surface and side surfaces of the wiring pattern 3 by electrodeposition coating. However, as shown in FIGS. 8A and 8B, for example, in the electrodeposition process, a cover metal layer 30 as an example of a protective layer is formed on the upper surface and side surfaces of the wiring pattern 3 by electrolytic plating. Also good.

  Examples of the cover metal layer 30 formed by the electrolytic plating method include gold, silver, copper, zinc, nickel, and chromium.

  In the first modification, a desired function (durability, ion migration preventing property, etc.) can be imparted to the wiring pattern 3 according to the type of metal. Further, by making the material of the cover metal layer 30 the same as that of the wiring pattern 3, the surface property and shape of the wiring pattern 3 can be adjusted.

  In the electrodeposition process, electrolytic plating and electrodeposition coating may be combined.

Second Modification The manufacturing method of the inductor 1 according to the embodiment includes the second magnetic layer arranging step. For example, although not shown, the second magnetic layer arranging step may not be provided. That is, the manufactured inductor 1 may not include the second magnetic layer 18 and the adhesive layer 19. From the viewpoint of providing a higher inductance, the method for manufacturing the inductor 1 preferably includes a second magnetic layer arranging step.

Third Modification The shape of the wiring pattern 3 is not limited to the above, and although not shown, the wiring pattern 3 may have, for example, a meander shape (meandering shape), a loop shape having a substantially circular shape in plan view, or the like. Good.

  Although not shown, the inductor 1 may not include the alignment mark 7 in the base insulating layer 2 by subsequent outer shape processing or the like.

<Other embodiments>
In the method for manufacturing a wiring board according to the first embodiment, the functional layer is a magnetic layer (first magnetic layer 5). For example, although not shown, the functional layer is a thermal conductive layer, radio wave as a wiring board other than the inductor 1. A shielding layer, a radio wave absorption layer, or the like can also be used.

  As a heat conductive layer, the heat conductive sheet of Unexamined-Japanese-Patent No. 2012-238819 and Unexamined-Japanese-Patent No. 2014-62220 is mentioned, for example.

  As the radio wave shielding layer, for example, a radio wave shield disclosed in JP 2007-194570 A can be cited.

  Examples of the radio wave absorption layer include a radio wave absorption sheet disclosed in JP-A-2001-44687.

  This embodiment also has the same operational effects as the first embodiment.

DESCRIPTION OF SYMBOLS 1 Inductor 2 Base insulating layer 3 Wiring pattern 4 Cover insulating layer 5 1st magnetic layer 6 Through-hole 8 Laminated body 12 Metal thin film 30 Cover metal layer

Claims (4)

A preparing step of preparing a laminate including an insulating layer having a through hole and a metal layer disposed on one side in the thickness direction of the insulating layer;
A wiring formation step of forming a wiring pattern by a subtractive method so as to overlap the through hole when projected in the thickness direction;
A method of manufacturing a wiring board, comprising: an electrodeposition step of covering the wiring pattern with a protective layer by supplying power for electrodeposition through the through hole. Before the wiring formation step, a conductor layer arrangement step of arranging a conductor layer on the other side in the thickness direction of the insulating layer;
The method for manufacturing a wiring board according to claim 1, further comprising a conductor layer removing step of removing the conductor layer after the electrodeposition step. The method of manufacturing a wiring board according to claim 1, further comprising a functional layer arranging step of arranging a functional layer on one side in the thickness direction of the insulating layer and the protective layer after the electrodeposition step. . The method for manufacturing a wiring board according to claim 1, wherein the protective layer is an electrodeposition coating film.

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