Circuit board with built-in conductor

Abstract

A circuit board having a built-in conductor includes: a base material having a first surface, a second surface located on the opposite side of the first surface in the thickness direction, and a through hole extending in the thickness direction; a first wiring layer disposed on the first surface of the substrate; a second wiring layer disposed on a second surface of the base material; and a first conductor and a second conductor which are arranged in the through hole and respectively extend in the thickness direction, the circuit board with the built-in conductor further includes an isolation insulating layer in the through hole, and the isolation insulating layer is located between the first conductor and the second conductor and isolates the first conductor from the second conductor in a plan view as viewed in the thickness direction.

Description

Technical Field

[0001] This invention relates to a conductor-embedded circuit board. Background Technology

[0002] Voltage regulation modules are used to supply power to computing devices such as CPUs and GPUs. As voltage regulation modules, buck switching regulator modules, which combine functional components such as switching elements, inductors, and capacitors, are known.

[0003] Such voltage regulation modules are typically arranged side-by-side with the computing processing unit on a main surface of the system substrate (motherboard). In contrast, a scheme has been proposed in which the voltage regulation module is arranged on the main surface of the system substrate opposite to the main surface on which the computing processing unit is arranged (see Patent Document 1).

[0004] Patent Document 1 discloses a three-layer voltage regulation module with a magnetic core assembly disposed between two circuit board assemblies. A conductor constituting an inductor is embedded within the magnetic core assembly.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: U.S. Patent Application Publication No. 2020 / 0111597 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] In the voltage regulation module of Patent Document 1, there is room for improvement in the idea of ​​further reducing the size of the structure containing the conductor.

[0010] Therefore, the object of the present invention is to solve the aforementioned problems and provide a conductor-embedded circuit board that can be further miniaturized.

[0011] means for solving problems

[0012] The conductor-embedded circuit board disclosed herein includes: a substrate having a first surface, a second surface located on the side opposite to the first surface in the thickness direction, and a through hole extending in the thickness direction; a first wiring layer disposed on the first surface of the substrate; a second wiring layer disposed on the second surface of the substrate; and a first conductor and a second conductor disposed within the through hole and extending in the thickness direction, wherein the conductor-embedded circuit board further includes an insulating layer in the through hole, which, when viewed from above along the thickness direction, is located between the first conductor and the second conductor and isolates the first conductor from the second conductor.

[0013] The effects of the invention

[0014] According to the present invention, a conductor-embedded circuit board that can be further miniaturized is provided. Attached Figure Description

[0015] Figure 1 This is a schematic perspective view of the inductor-embedded circuit board according to the first embodiment.

[0016] Figure 2 yes Figure 1 A schematic exploded perspective view of the circuit board embedded in the inductor.

[0017] Figure 3A It means Figure 1 A schematic top view of the inductor's built-in circuit board, including the built-in substrate and part of the wiring layer.

[0018] Figure 3B It means Figure 3A A schematic bottom view of the component's built-in substrate and part of the wiring layer.

[0019] Figure 3C It is along Figure 3A and Figure 3B A schematic cross-sectional view of the IIIC-IIIC line.

[0020] Figure 4 It is a schematic 3D diagram of a single inductor unit.

[0021] Figure 5A yes Figure 4 A schematic top view of a single inductor unit.

[0022] Figure 5B It is along Figure 5A A schematic cross-sectional view of the VB-VB line.

[0023] Figure 6 This is a diagram showing the basic circuit structure of a voltage regulation module (buck converter).

[0024] Figure 7A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0025] Figure 7B It is along Figure 7A A schematic process cross-sectional view of line VIIB-VIIB shown.

[0026] Figure 8A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0027] Figure 8B It is along Figure 8AA schematic process cross-sectional view of line VIIIB-VIIIB shown.

[0028] Figure 9A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0029] Figure 9B It is along Figure 9A A schematic process cross-sectional view of the IXB-IXB line shown.

[0030] Figure 10A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0031] Figure 10B It is along Figure 10A A schematic process cross-sectional view of the XB-XB line shown.

[0032] Figure 11A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0033] Figure 11B It is along Figure 11A A schematic cross-sectional view of the XIB-XIB line shown.

[0034] Figure 12A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0035] Figure 12B It is along Figure 12A A schematic cross-sectional view of the XIIB-XIIB line shown.

[0036] Figure 13A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0037] Figure 13B It is along Figure 13A A schematic cross-sectional view of the XIIIB-XIIIB line shown.

[0038] Figure 14A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0039] Figure 14B It is along Figure 14A A schematic cross-sectional view of the XIVB-XIVB line shown.

[0040] Figure 15A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0041] Figure 15B It is along Figure 15AA schematic cross-sectional view of the XVB-XVB line shown.

[0042] Figure 16A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0043] Figure 16B It is along Figure 16A A schematic cross-sectional view of the XVIB-XVIB line shown.

[0044] Figure 17A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0045] Figure 17B It is along Figure 17A A schematic cross-sectional view of the XVIIB-XVIIB line shown.

[0046] Figure 18A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0047] Figure 18B Is with Figure 18A The corresponding schematic bottom view of the process.

[0048] Figure 18C It is along Figure 18A A schematic cross-sectional view of the XVIIIC-XVIIIC line shown.

[0049] Figure 19A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0050] Figure 19B Is with Figure 19A The corresponding schematic bottom view of the process.

[0051] Figure 19C It is along Figure 19A A schematic cross-sectional view of the XIXC-XIXC line shown.

[0052] Figure 20A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0053] Figure 20B Is with Figure 20A The corresponding schematic bottom view of the process.

[0054] Figure 20C It is along Figure 20A The schematic process cross-sectional view of the XXC-XXC line is shown.

[0055] Figure 21A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0056] Figure 21B Is with Figure 21A The corresponding schematic bottom view of the process.

[0057] Figure 21C It is along Figure 21A The diagram shows a schematic cross-sectional view of the XXIC-XXIC line.

[0058] Figure 22A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0059] Figure 22B Is with Figure 22A The corresponding schematic bottom view of the process.

[0060] Figure 22C It is along Figure 22A The schematic process cross-sectional view of the XXIIC-XXIIC line is shown.

[0061] Figure 23A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0062] Figure 23B Is with Figure 23A The corresponding schematic bottom view of the process.

[0063] Figure 23C It is along Figure 23A A schematic cross-sectional view of the XXIIIC-XXIIIC line shown.

[0064] Figure 24A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0065] Figure 24B Is with Figure 24A The corresponding schematic bottom view of the process.

[0066] Figure 24C It is along Figure 24A A schematic cross-sectional view of the XIVC-XXIVC line shown.

[0067] Figure 25A This is a schematic top view showing the component-embedded substrate and part of the wiring layer of the inductor-embedded circuit board in the second embodiment.

[0068] Figure 25B It means Figure 25A The diagram shows a schematic bottom view of the component's built-in substrate and part of the wiring layer.

[0069] Figure 25C It is along Figure 25A andFigure 25B A schematic cross-sectional view of the XXVC-XXVC line.

[0070] Figure 26A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0071] Figure 26B It is along Figure 26A The schematic process cross-sectional view of the XXVIB-XXVIB line is shown.

[0072] Figure 27A It is a schematic top view illustrating the manufacturing process of a single inductor unit.

[0073] Figure 27B It is along Figure 27A A schematic process cross-sectional view of line XXVIIB-XXVIIB shown.

[0074] Figure 28A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0075] Figure 28B It is along Figure 28A A schematic process cross-sectional view of the XXVIIIB-XXVIIIB line shown.

[0076] Figure 29A It is a schematic top view illustrating the manufacturing process of a circuit board.

[0077] Figure 29B It is along Figure 29A The schematic process cross-sectional view of the XXIXB-XXIXB line is shown.

[0078] Figure 30 This is a schematic perspective view of the conductor-containing portion of the circuit board according to the third embodiment.

[0079] Figure 31A yes Figure 30 A schematic top view of a conductor containing a portion.

[0080] Figure 31B It is along Figure 31A A schematic cross-sectional view of the XXXIB-XXXIB line.

[0081] Figure 32A This is a schematic top view of a modified example 1 of a conductor containing a portion.

[0082] Figure 32B It is along Figure 32A A schematic cross-sectional view of the XXXIIB-XXXIIB line.

[0083] Figure 33A This is a schematic top view of a modified example 2 of a conductor containing a portion.

[0084] Figure 33B It is along Figure 33A A schematic cross-sectional view of the XXXIIIB-XXXIIIB line.

[0085] Figure 34A This is a schematic top view of variation 3 of the conductor containing a portion.

[0086] Figure 34B It is along Figure 34A A schematic cross-sectional view of the XXXIVB-XXXIVB line.

[0087] Figure 35A This is a schematic top view of variation 4 of the conductor containing a portion.

[0088] Figure 35B It is along Figure 35A A schematic cross-sectional view of the XXXVB-XXXVB line.

[0089] Figure 36A This is a schematic top view of variation 5 of the conductor containing a portion.

[0090] Figure 36B It is along Figure 36A A schematic cross-sectional view of the XXXVIB-XXXVIB line.

[0091] Figure 37A This is a schematic top perspective view of the conductor containing the second electrode in structural example (2).

[0092] Figure 37B This is a schematic bottom perspective view of the conductor containing the first electrode in structural example (2).

[0093] Figure 37C This is a schematic top view illustrating the magnetic field generated in a first structure.

[0094] Figure 38A This is a diagram illustrating an example of the circuit structure of a voltage regulation module using the circuit board of structure example (2).

[0095] Figure 38B It is a simplification Figure 38A The circuit structure shown is a diagram.

[0096] Figure 38C It means Figure 38B The diagram shows phase 1 of the circuit.

[0097] Figure 38D It means Figure 38AA schematic diagram of the waveform of the ripple current in the circuit shown.

[0098] Figure 39A This is a schematic top perspective view of the conductor containing the second electrode in structural example (3).

[0099] Figure 39B This is a schematic bottom perspective view of the conductor containing the first electrode in structural example (3).

[0100] Figure 40 This is a diagram illustrating an example of the circuit structure of a voltage regulation module using the circuit board of structure example (3).

[0101] Figure 41A This is a schematic top perspective view of the conductor containing the second electrode in structural example (5).

[0102] Figure 41B This is a schematic bottom perspective view of the conductor containing the first electrode in structural example (5).

[0103] Figure 42A This is a schematic three-dimensional diagram illustrating the manufacturing method of the first structure M.

[0104] Figure 42B This is a schematic three-dimensional diagram illustrating the manufacturing method of the first structure M.

[0105] Figure 42C This is a schematic three-dimensional diagram illustrating the manufacturing method of the first structure M.

[0106] Figure 43A It is a schematic three-dimensional diagram illustrating the manufacturing method of a conductor containing a part.

[0107] Figure 43B This is a schematic three-dimensional diagram illustrating the manufacturing method of the first structure M.

[0108] Figure 44A This is a schematic top view illustrating an example of the design method for the first structure M.

[0109] Figure 44B This is a schematic top view illustrating an example of the design method for the first structure M.

[0110] Figure 45 This is a schematic cross-sectional view illustrating the voltage regulation module of the fourth embodiment.

[0111] Figure 46 This is a schematic cross-sectional view showing the built-in components of an inductor in a reference example. Detailed Implementation

[0112] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments. Furthermore, in the drawings, substantially identical components are labeled with the same reference numerals. For illustrative purposes, the dimensions of elements in the drawings are sometimes exaggerated, and are not necessarily limited to a scale.

[0113] Hereinafter, a substrate with built-in conductors will be referred to as a "conductor-embedded circuit board". Sometimes, a conductor-embedded circuit board in which multiple conductors built into a conductor are connected in series to form an inductor will be referred to as an "inductor-embedded circuit board". Sometimes, the conductor-embedded circuit board or the inductor-embedded circuit board will be simply referred to as a "circuit board".

[0114] Furthermore, for ease of explanation, the terms "up," "down," "right," "left," and "side," etc., used to indicate direction are assumed to represent the state of normal use, but this does not limit the usage state of the circuit board disclosed herein. Also, in this specification, "orthogonal" means within a range of 90° ± 10°. "Parallel" means, for example, within a range of ± 5°. Furthermore, the following descriptions sometimes use terms like shape and orientation, but these include not only the described shape and orientation but also cases where the shape and orientation are approximately the same. For example, "cubic prism" includes not only a cuboid but also cases where the shape and orientation are approximately cuboid.

[0115] In the accompanying drawings described below, the mutually orthogonal X-axis, Y-axis, and Z-axis are schematically shown for reference. The Z-axis is the axis corresponding to the thickness direction of the circuit board. In the following description, when referred to only as the X-direction, Y-direction, or Z-direction, each axis includes two opposing directions (e.g., the -X-direction and the +X-direction).

[0116] Implementation Method 1

[0117] (The foundational insights)

[0118] The inventors have conducted in-depth research on the structure of the inductor-embedded circuit board for further thinning of the voltage regulation module. As a result, the following insights were obtained.

[0119] Due to the dramatic increase in data traffic in information communication, the current required by computing devices used in data centers and other similar applications has increased. With this increased current, it is necessary to suppress the transient voltage response (voltage fluctuations) to current variations (load variations) affecting the computing devices.

[0120] When a voltage regulation module is placed on the main surface of the system substrate opposite to the main surface where the computing processing device is located (hereinafter referred to as the "opposite surface"), the output terminal of the voltage regulation module can be placed close to the input terminal of the computing processing device. Therefore, transient voltage responses can be suppressed more effectively.

[0121] In the voltage regulator module located on the opposite side, in addition to built-in inductors and other functional components, a thinner profile is also desired.

[0122] However, as mentioned above, in the voltage regulation module disclosed in Patent Document 1, it is sometimes difficult to suppress the thickness of the module. In Patent Document 1, an inductor is formed by arranging a conductor that penetrates the magnetic core in the thickness direction in the magnetic core assembly (see [reference]). Figure 46 With this construction, the thickness of the magnetic core assembly is limited by the height of the conductors within the core. Additionally, two circuit board assemblies are required above and below the magnetic core assembly. Therefore, the thickness of the module further increases due to the thickness of the two circuit board assemblies and the welded connections between them.

[0123] Therefore, the inventors have made a new discovery: by dividing the inductor into multiple parts and embedding them in a circuit board, the thickness of the inductor-embedded circuit board can be reduced, and such an inductor-embedded circuit board can be used to reduce the thickness of the voltage regulation module. Based on this new insight, the inventors have completed the following embodiments.

[0124] [Overall structure of the inductor's built-in circuit board]

[0125] First, refer to Figure 1 Figure 5 illustrates an outline of the inductor-embedded circuit board (hereinafter referred to as "circuit board") according to the first embodiment of this disclosure.

[0126] Figure 1 This is a schematic perspective view of a circuit board according to an embodiment of the present disclosure. Figure 2 yes Figure 1 A schematic exploded perspective view of the circuit board.

[0127] like Figure 1 As shown, the circuit board 1 has, for example, a generally cuboid shape. The circuit board 1 has a first main surface s1 and a second main surface s2 located on the opposite side of the first main surface s1 in the thickness direction (Z direction). In each figure, for convenience, the thickness direction of the circuit board 1 is designated as the Z direction, the direction parallel to the long sides of the main surfaces s1 and s2 of the circuit board 1 is designated as the X direction, and the direction parallel to the short sides is designated as the Y direction.

[0128] like Figure 2 As shown, the circuit board 1 includes a first wiring structure 100, a second wiring structure 200, and a component-embedded substrate 300. In the thickness direction (Z direction) of the circuit board 1, the component-embedded substrate 300 is located between the first wiring structure 100 and the second wiring structure 200. In this example, the first wiring structure 100 is located on the first main surface s1 side of the component-embedded substrate 300, and the second wiring structure 200 is located on the second main surface s2 side of the component-embedded substrate 300.

[0129] The component-embedded substrate 300 includes a substrate 10 (also referred to as a "core substrate") and components such as an inductor 2 and a two-terminal capacitor disposed within the substrate 10. In this specification, components disposed (embedded) within the substrate 10 are sometimes collectively referred to as "embedded components".

[0130] The substrate 10 has, for example, a generally cuboid shape. The substrate 10 has a first surface (here, the lower surface) 11 and a second surface (here, the upper surface) 12 located on the opposite side of the first surface 11 in the Z direction. The first surface 11 is located on the side of the first main surface s1 of the circuit board 1, and the second surface 12 is located on the side of the second main surface s2 of the circuit board 1.

[0131] The inductor 2, two-terminal capacitor and other built-in components are disposed in the through hole provided in the substrate 10.

[0132] The first wiring structure 100 is located on the first surface 11 of the substrate 10. The first wiring structure 100 has a laminated structure in which multiple (here, three) insulating layers 101 to 103 and multiple wiring layers 110 to 130 are alternately stacked in the thickness direction (-Z direction). Here, starting from the substrate 10 side, the insulating layer 101, wiring layer 110, insulating layer 102, wiring layer 120, insulating layer 103, and wiring layer 130 are stacked sequentially.

[0133] The second wiring structure 200 is located on the second surface 12 of the substrate 10. The second wiring structure 200 has a laminated structure in which multiple (here, three) insulating layers 201 to 203 and multiple wiring layers 210 to 230 are alternately stacked in the thickness direction (+Z direction). Here, starting from the substrate 10 side, the insulating layer 201, wiring layer 210, insulating layer 202, wiring layer 220, insulating layer 203, and wiring layer 230 are stacked sequentially.

[0134] Each wiring layer 110-130, 210-230 has electrodes, wiring, terminals, etc. Each insulation layer 101-103, 201-203 has multiple conductive paths v for electrically connecting the electrodes located above and below each other.

[0135] Alternatively, the circuit board 1 may also include solder mask layers 105 and 205. Solder mask layer 105 is disposed on the first main surface s1 side of the first wiring structure 100. Solder mask layer 205 is disposed on the second main surface s2 side of the second wiring structure 200. Solder mask layers 105 and 205 are provided to suppress solder flow when components or BGAs (Ball Grid Arrays) are mounted on the circuit board 1 by soldering.

[0136] [Component Embedded Substrate]

[0137] The following is for referenceFigures 3A-3C This section describes the more detailed construction of the embedded substrate 300 in the component. Figure 3A and Figure 3B These are schematic top and bottom views, respectively, showing the component's built-in substrate and part of the wiring layer. Figure 3C It is along Figure 3A and Figure 3B A schematic cross-sectional view of the IIIC-IIIC line. Figure 3C In addition to the component-embedded substrate 300, the wiring layer 110 located on the side closest to the substrate 10 in the first wiring structure 100 and the wiring layer 210 located on the side closest to the substrate 10 in the second wiring structure 200 are also shown. Figure 3A and Figure 3B In the diagram, for ease of understanding, double-dotted lines are used to represent the electrodes within wiring layers 210 and 110.

[0138] like Figures 3A-3C As shown, the component's built-in substrate 300 includes a substrate 10, an inductor 2, an input capacitor 5, an output capacitor 6, and multiple through conductors 7. The inductor 2 has three inductor units 20a to 20c.

[0139] The inductor unit 20a-20c, the input capacitor 5, the output capacitor 6, and the core conductor 7 are located inside the substrate 10.

[0140] like Figure 3C As shown, the inductor 2 includes multiple (three in this case) conductors 3a to 3c and multiple (three in this case) magnetic bodies 4a to 4c. The conductors 3a to 3c extend in such a way that they pass through a corresponding magnetic body 4a to 4c in the Z direction.

[0141] In this embodiment, conductor 3a and magnetic material 4a constitute an inductor unit 20a. Similarly, conductor 3b and magnetic material 4b constitute inductor unit 20b, and conductor 3c and magnetic material 4c constitute inductor unit 20c. Inductor units 20a to 20c are connected in series to form an inductor. In this specification, when multiple inductors are connected in series to function as a single inductor, each of the multiple inductors connected in series is referred to as an "inductor unit". That is, the three components described as inductor units 20a to 20c can each function as an inductor individually.

[0142] Conductors 3a to 3c are arranged at intervals within the substrate 10 when viewed from above along the Z direction (hereinafter sometimes simply referred to as "top view"). Each conductor 3a to 3c extends in the Z direction. In the illustrated example, conductors 3a to 3c are arranged sequentially in the X direction when viewed from above.

[0143] Magnetic body 4a is located around conductor 3a in such a way that it surrounds the peripheral surface of conductor 3a. Similarly, magnetic bodies 4b and 4c are located around conductors 3b and 3c in such a way that they surround the peripheral surfaces of conductors 3b and 3c, respectively. Adjacent magnetic bodies 4a to 4c are separated from each other by the partition walls of the substrate 10.

[0144] In the illustrated example, the ends (first ends) of conductors 3a and 3b on the first surface 11 side are electrically connected to each other by the first connecting electrode 111 within the wiring layer 110. Furthermore, the ends (second ends) of conductors 3b and 3c on the second surface 12 side are electrically connected to each other by the second connecting electrode 212 within the wiring layer 210. Thus, conductors 3a to 3c are connected in series.

[0145] In this embodiment, inductor units 20a to 20c are connected in series by a first connecting electrode 111 and a second connecting electrode 212 to form inductor 2. By dividing the inductor into three or more (in this case, three) inductor units 20a to 20c and arranging them within the substrate 10, the thickness of the substrate 10 required to assemble the inductor 2 can be reduced while ensuring the desired inductance value.

[0146] The following describes in more detail the substrate 10 of the component-integrated substrate 300 and each integrated component.

[0147] (Substrate 10)

[0148] like Figure 3C As shown, the substrate 10 has an inductor configuration region r1 for supplying inductors 2, a capacitor configuration region r2 for supplying capacitors 5 and 6, and a core conductor configuration region r3 for supplying a plurality of core conductors 7. In this example, the inductor configuration region r1, the capacitor configuration region r2, and the core conductor configuration region r3 are arranged sequentially in the X direction.

[0149] In the inductor placement area r1, through holes 13a to 13c are provided on the substrate 10, extending from the first surface 11 to the second surface 12. Each through hole 13a to 13c is, for example, a quadrangular prism-shaped opening. In the illustrated example, the through holes 13a to 13c are arranged in the X direction, and adjacent through holes are separated by a partition wall of the substrate 10. Inductor units 20a to 20c are respectively disposed within the through holes 13a to 13c.

[0150] In the capacitor placement area r2, two through holes 14 and 15 are provided on the substrate 10, extending from the first surface 11 to the second surface 12. Each through hole 14 and 15 is, for example, a quadrangular prism-shaped opening. In the illustrated example, the through holes 14 and 15 are arranged in the Y direction and are separated from each other by the partition wall of the substrate 10. An input capacitor 5 is disposed in the through hole 14, and an output capacitor 6 is disposed in the through hole 15.

[0151] In the core through-conductor configuration region r3, a plurality of through holes 16 are provided in the substrate 10. In the illustrated example, 15 cylindrical through holes 16 are arranged in a matrix in the X and Y directions. A core through conductor 7 is disposed in each through hole 16. The core through conductor 7 can function as a connecting conductor for electrically connecting the circuits in the first wiring configuration 100 and the circuits in the second wiring configuration 200.

[0152] (Inductor unit 20A~20C)

[0153] Reference Figures 4-5B This describes the detailed structure of a single inductor unit. Figure 4 It is a schematic 3D diagram of a single inductor unit. Figure 5A yes Figure 4 A schematic top view of a single inductor unit. Figure 5B It is along Figure 5A A schematic cross-sectional view of the VB-VB line. Here, we will use the inductor unit 20a as an example for explanation.

[0154] The inductor unit 20a includes a magnetic body 4a, a conductor 3a passing through the magnetic body 4a, a first electrode 31a electrically connected to a first end of the conductor 3a, and a second electrode 32a electrically connected to a second end of the conductor 3a.

[0155] The magnetic body 4a has a shape corresponding to the through hole in the substrate 10, for example, it is a quadrangular prism (in this case, a cuboid). The magnetic body 4a has a through hole 41 extending in the thickness direction (Z direction). The through hole 41 is, for example, cylindrical. In top view, the through hole 41 is positioned approximately at the center of the magnetic body 4a.

[0156] Conductor 3a is disposed inside the through-hole 41 of the magnetic body and extends in the Z direction. Conductor 3a has a shape corresponding to the shape of the through-hole 41 of the magnetic body. Here, conductor 3a is a cylinder with a first end face e1 and a second end face e2, and a peripheral surface 3s located between these end faces e1 and e2. The peripheral surface 3s of conductor 3a is surrounded by magnetic body 4a. The first end face e1 and the second end face e2 are at least partially exposed from magnetic body 4a. The first end face e1 is a downward (towards the -Z direction) face. The first end face e1 may also be substantially coplanar with the lower surface of magnetic body 4a. The second end face e2 is an upward (towards the +Z direction) face. The second end face e2 may also be substantially coplanar with the upper surface of magnetic body 4a.

[0157] Alternatively, the inductor unit 20a may also include a resin component that seals the conductor 3a within a magnetic body through-hole 41 of the magnetic body 4a. The resin component may include, for example, an insulating portion 23 configured to fill the gap between the inner wall of the magnetic body through-hole 41 and the conductor 3a. The resin component may also cover the upper and lower surfaces of the magnetic body 4a.

[0158] The first electrode 31a is disposed on the first end face e1 of the conductor 3a via the first single-cell insulating portion 21. The first electrode 31a is electrically connected to the first end of the conductor 3a via at least one (here, multiple) through-conductors 33 disposed within the first single-cell insulating portion 21. In the illustrated example, one end of the through-conductor 33 is connected to the first electrode 31a, and the other end is connected to the first end face e1 of the conductor 3a.

[0159] The second electrode 32a is disposed on the second end face e2 of the conductor 3a via the second monomer insulating portion 22. The second electrode 32a is electrically connected to the second end of the conductor 3a via at least one (here, multiple) through conductors 34 disposed within the second monomer insulating portion 22. In the illustrated example, one end of the through conductor 34 is connected to the second electrode 32a, and the other end is connected to the second end face e2 of the conductor 3a.

[0160] Alternatively, the first monomer insulating portion 21 may include the portion of the resin component covering the lower surface of the magnetic body 4a. Figure 10B The sealing insulation layer 24 shown. Similarly, the second monomer insulation portion 22 may include the portion of the resin component covering the upper surface of the magnetic body 4a. Figure 10B The sealing insulation layer 25 is shown.

[0161] Alternatively, when viewed from above, the first electrode 31a and the second electrode 32a may have a larger area than the corresponding conductor 3a. In the illustrated example, when viewed from above, the first electrode 31a overlaps entirely with the first end face e1 of the conductor 3a and at least partially with the magnetic body 4a. The second electrode 32a overlaps entirely with the second end face e2 of the conductor 3a and at least partially with the magnetic body 4a.

[0162] The dimensions of each cuboid magnetic body 4a are, for example, 2.3 mm (X direction) × 3 mm (Y direction) × 1.8 mm (Z direction). The diameter of the cylindrical magnetic body through-hole 41 is, for example, 1.1 mm. The diameter of each cylindrical conductor 3a is 1.0 mm, and the thickness is 1.8 mm. In addition, the thickness of the first single-unit insulating portion 21 and the second single-unit insulating portion 22 is, for example, 30 μm.

[0163] In the illustrated example, conductors 3a-3c and the through-hole 41 are cylindrical, but they can also be prismatic. Furthermore, conductors 3a-3c and the through-hole 41 can extend from the upper surface to the lower surface of the magnetic body 4a, or they can be non-parallel to the Z-direction.

[0164] like Figures 3A-3C As shown, the other inductor units 20b and 20c are the same as inductor unit 20a, including magnetic bodies 4b and 4c, conductors 3b and 3c, first electrodes 31b and 31c, and second electrodes 32b and 32c. Inductor units 20b and 20c also have the same characteristics as those described above. Figures 4-5B The inductor unit 20a described has the same structure. In this embodiment, the inductor units 20a to 20c have the same size, but they may also be different.

[0165] (Capacitors 5 and 6)

[0166] like Figure 3C As shown, the input capacitor 5 is a two-terminal capacitor comprising a lower electrode 51, an upper electrode 52, and a dielectric 53. The dielectric 53 is located between the lower electrode 51 and the upper electrode 52 in the Z direction. The lower electrode 51 is located on the first surface 11 side of the dielectric 53, and the upper electrode 52 is located on the second surface 12 side of the dielectric 53. The input capacitor 5 can function as a bypass capacitor for the input power line of the voltage regulation module.

[0167] Similarly, the output capacitor 6 also includes a lower electrode 61 ( Figure 3B ), Upper electrode 62 ( Figure 3AThe output capacitor 6 is a two-terminal capacitor with a dielectric material located between the lower electrode 61 and the upper electrode 62 in the Z direction. The lower electrode 61 is located on the first surface 11 side of the dielectric material, and the upper electrode 62 is located on the second surface 12 side of the dielectric material. The output capacitor 6 can function as a bypass capacitor for the output power line of the voltage regulation module.

[0168] (Sealing component 8)

[0169] The component's built-in substrate 300 also includes a sealing member 8 that seals the substrate 10, which internally houses inductor units 20a-20c, an input capacitor 5, an output capacitor 6, and a core-through conductor 7. Figure 3C In the example shown, the sealing member 8 is disposed in the gap between the inner wall of the through holes 13a-13c, 14-16 and the component located in the through hole. Alternatively, the sealing member 8 may also be disposed on the first surface 11 and the second surface 12 of the substrate 10.

[0170] [Wiring layers 110, 210]

[0171] Next, refer to Figures 3A-3C The structure of the wiring layers 110 and 210 disposed on the first surface 11 and the second surface 12 of the substrate 10 is explained.

[0172] Wiring layer 110 (sometimes referred to as "first wiring layer") is disposed on the first surface 11 of substrate 10, separated by a first insulating portion 91. The "first insulating portion" is the insulating portion located between wiring layer 110 and the first surface 11 of substrate 10. In this embodiment, the first insulating portion 91 includes a portion of the sealing member 8 of the component embedded in substrate 300. Figure 17B The lower insulating layer 81 shown and the insulating layer 101 located on the side closest to the substrate 10 of the first wiring structure 100 Figure 2 ).

[0173] Wiring layer 210 (sometimes referred to as "second wiring layer") is disposed on the second surface 12 of substrate 10, separated by a second insulating portion 92. The "second insulating portion" is the insulating portion located between wiring layer 210 and the second surface 12 of substrate 10. In this embodiment, the second insulating portion 92 includes a portion of the sealing member 8 of the component embedded in substrate 300. Figure 17B The upper insulating layer 82 shown and the insulating layer 201 located on the side closest to the substrate 10 of the second wiring structure 200 Figure 2 ).

[0174] Multiple conductive paths are formed within the first insulating portion 91 for electrically connecting the components within the substrate 10 to the electrodes within the wiring layer 210. Similarly, multiple conductive paths are formed within the second insulating portion 92 for electrically connecting the components within the substrate 10 to the electrodes within the wiring layer 210. One or more conductive paths may be provided for each electrode of the built-in component. To increase the connection area, it is preferable to provide multiple conductive paths for each electrode.

[0175] (Wiring layer 110)

[0176] like Figure 3B and Figure 3C As shown, the wiring layer 110 has a first connection electrode 111, a first inductor connection electrode 112 connected to the output terminal of the inductor, and a first input capacitor connection electrode 113. These electrodes 111 to 113 are arranged at a distance from each other.

[0177] The first connecting electrode 111 electrically connects the ends (first ends) of the conductors 3a and 3b on the first surface 11 side to each other. In the illustrated example, the first connecting electrode 111 is electrically connected to the first electrode 31a of the inductor unit 20a and the first electrode 31b of the inductor unit 20b via a pass conductor in the first insulating portion 91.

[0178] The planar shape of the first connecting electrode 111 is, for example, rectangular. Alternatively, when viewed from above, the first connecting electrode 111 may completely overlap with the conductors 3a and 3b, and preferably, it may completely overlap with the first electrodes 31a and 31b.

[0179] The first inductor connection electrode 112 electrically connects the first end of the conductor 3c, which serves as the output terminal of the inductor 2, to the lower electrode 61 of the output capacitor 6. In the illustrated example, the first inductor connection electrode 112 is electrically connected to the first electrode 31c of the inductor unit 20c and the lower electrode 61 of the output capacitor 6 via a conductive path within the first insulating portion 91.

[0180] The first input capacitor connection electrode 113 is electrically connected to the lower electrode 51 and the partial core through conductor 7 of the input capacitor 5 via a through conductor in the first insulating part 91.

[0181] (Wiring layer 210)

[0182] like Figure 3A and Figure 3C As shown, the wiring layer 210 has a second inductor connection electrode 211, a second connection electrode 212, a second input capacitor connection electrode 213, and an output capacitor connection electrode 214, all connected to the input terminals of the inductors. These electrodes 211 to 214 are arranged at a distance from each other.

[0183] The second inductor connection electrode 211 is electrically connected to the second end of the conductor 3a, which serves as the input terminal of the inductor 2. In the illustrated example, the second inductor connection electrode 211 is electrically connected to the second electrode 32a of the inductor unit 20a via a pass conductor within the second insulation portion 92.

[0184] The second connecting electrode 212 electrically connects the ends (second ends) of the conductors 3b and 3c on the second surface 12 side to each other. In the illustrated example, the second connecting electrode 212 is electrically connected to the second electrode 32b of the inductor unit 20b and the second electrode 32c of the inductor unit 20c via a conductive path in the second insulating portion 92.

[0185] The planar shape of the second connecting electrode 212 is, for example, rectangular. Alternatively, when viewed from above, the second connecting electrode 212 may completely overlap with the conductors 3b and 3c, and preferably, it may completely overlap with the second electrodes 32b and 32c.

[0186] The second input capacitor connection electrode 213 is electrically connected to the upper electrode 52 and the partial core through conductor 7 of the input capacitor 5 via a through conductor in the second insulating portion 92. Thus, the upper electrode 52 of the input capacitor 5 can be electrically connected to the input terminal Vin, located on the opposite side of the substrate 10, via the partial core through conductor 7.

[0187] The output capacitor connection electrode 214 is electrically connected to the upper electrode 62 and the partial core through conductor 7 of the output capacitor 6 via the through conductor in the second insulating part 92. Thus, the upper electrode 62 of the output capacitor 6 can be electrically connected to the ground terminal GND located on the opposite side of the substrate 10 via the partial core through conductor 7.

[0188] [Circuit structure of the voltage regulation module]

[0189] The circuit structure of the circuit board 1 in this embodiment will be explained. Here, the case of applying the circuit board 1 to a buck switching regulator (buck converter) will be used as an example for explanation.

[0190] Figure 6 This is a diagram showing the basic circuit structure of a voltage regulation module (buck converter). The voltage regulation module includes the circuit board 1 and the switching element SW of this embodiment.

[0191] The switching element SW includes MOSFETs 410 and 420, a switch input terminal SW_Vin, a switch output terminal SW_Vout, a switch GND terminal SW_GND, and a switch control terminal SW-CTL. Other switching elements can also be used instead of MOSFETs. The switching element SW is, for example, disposed on the first main surface of the circuit board 1 (see reference). Figure 45 ).

[0192] constitute Figure 6 The inductor 2, input capacitor 5, and output capacitor 6 of the circuit shown are built into the circuit board 1. The control terminal CTL, input terminal Vin, output terminal Vout, and ground terminal GND are formed, for example, on the topmost wiring layer 230 of the circuit board 1 (see reference). Figure 23A Additionally, terminal pads for each terminal of the switching element SW are formed on the wiring layer 130 located at the bottom of the circuit board 1 (see reference). Figure 23B ).

[0193] exist Figure 6 In the circuit shown, the high-side MOSFET 410 is connected to the input terminal Vin. The low-side MOSFET 420 is connected to the GND terminal of MOSFET 410. An input voltage is applied from the input terminal Vin to the switch input terminal SW_Vin.

[0194] Inductor 2 is composed of individual inductor units 20a to 20c connected in series. The input terminal p2 of inductor 2 is connected to the output terminal SW_Vout of the switch.

[0195] The input capacitor 5 is connected in a shunt to the switch input terminal SW_Vin. Here, the upper electrode 52 of the input capacitor 5 is connected to the switch input terminal SW_Vin, and the lower electrode 51 is connected to the ground terminal GND.

[0196] The output capacitor 6 is connected to the output terminal Vout via a shunt connection. Here, the lower electrode 61 of the output capacitor 6 is connected to the output terminal Vout, and the upper electrode 62 is connected to the ground terminal GND.

[0197] According to this circuit, the pulse waveform generated in the switching element SW by alternately turning MOSFETs 410 and 420 on / off is smoothed by inductor 2 and output capacitor 6. This generates the desired output voltage, which is output from the output terminal Vout.

[0198] [Materials of each constituent element]

[0199] The magnetic materials of the magnetic body (magnetic matrix) 4a to 4c, which are the unit cells 20a to 20c of the inductor, can be materials with magnetic permeability such as metallic magnetic materials or ferrite sintered bodies. Ideally, the magnetic material should be a composite material of metallic magnetic powder and organic materials. This is because the magnetostriction of metallic magnetic materials is smaller than that of ferrite sintered bodies, thus reducing the degradation of the metallic magnetic material's characteristics caused by external stress when embedded in the substrate 10. Furthermore, the composite form of metallic magnetic powder and organic materials improves DC superposition characteristics and facilitates the processing for forming through-holes. Moreover, by using organic materials, for example, when embedded in the substrate 10, externally applied stress can be elastically absorbed, reducing the internal stress applied to the metallic magnetic powder. Therefore, inductance reduction caused by magnetostriction can be prevented. The metallic magnetic material can be soft magnetic materials such as Fe, Co, Ni, alloys containing them (FeSi-based alloys such as FeSiCr, FeSiAl, FeCo-based alloys, NiFe-based alloys, etc.), or their amorphous alloys. Organic materials include, for example, organic insulating materials composed of epoxy resins, polyimides, liquid crystal polymers, and bismaleimides.

[0200] The conductors 3a to 3c that pass through the magnetic bodies 4a to 4c and the core conductor 7 are made of a metallic material with low volume resistivity. As a metallic material, it is desirable to use a material with Cu as the main component, considering ease of processing and commonality with the conductors used in the wiring layer (circuit layer).

[0201] The substrate 10, the first monomer insulating portion 21 and the second monomer insulating portion 22, the sealing member 8, and the insulating layers 101-103 and 201-203 constituting the printed circuit board are, for example, composed of thermosetting resin and cross-fibers of inorganic fillers or inorganic materials. Examples of thermosetting resins include epoxy resins, acrylic resins, and polyimides. Examples of cross-fibers of inorganic fillers or inorganic materials include SiO2.

[0202] The wiring layers 110-130 and 210-230 constituting the circuit board 1 are, for example, metal layers with Cu as the main material. The conductors disposed in the insulating layers 101-103 and 201-203 are also metal conductors with Cu as the main material. In the wiring layers exposed through the openings of the solder mask layers 105 and 205, for the purpose of corrosion prevention, rust prevention, or optimization of solder wettability, an AuNi coating can be formed on the surface, or rust prevention treatment can be implemented.

[0203] [Manufacturing method of circuit board]

[0204] The manufacturing method of circuit board 1 includes the following steps.

[0205] (1) The process of preparing components such as inductor units and two-terminal capacitors;

[0206] (2) An embedding process in which components such as inductor units are disposed within a substrate; and

[0207] (3) Wiring structure forming process in which wiring structures are formed on the surface and back of the substrate.

[0208] The process for preparing components (1) includes the manufacturing process of individual inductor units. The following describes each process in turn.

[0209] (Manufacturing process of a single inductor unit)

[0210] Figures 7A-14A These are schematic top views illustrating the manufacturing process of a single inductor unit. Figures 7B-14B They are along Figures 7A-14A The schematic process cross-sectional view shown is along line AA.

[0211] like Figure 7A and Figure 7B As shown, a magnetic block 40, which forms a magnetic body (magnetic substrate) into an inductor unit cell, is formed, for example, by a method such as pressure molding. Next, a plurality of (in this case, six) magnetic through holes 41 are formed in the magnetic block 40 by drilling or the like. The magnetic through holes 41 are arranged at intervals when viewed from above.

[0212] Here, for example, a flat magnetic block 40 with a thickness of 1.8 mm is formed by hot pressing. Then, a cylindrical magnetic through hole 41 with a diameter of 1.1 mm is formed in the magnetic block 40 using a drill bit (drill bit diameter: 1.1 mmφ). Alternatively, after the magnetic block 40 is formed, it can be machined to the desired thickness by grinding or the like.

[0213] Next, as Figure 8A and Figure 8B As shown, conductors 3 are arranged in each magnetic through hole 41 of the magnetic block 40.

[0214] Next, as Figure 9A and Figure 9BAs shown, a resin component is formed from the upper and lower surfaces of the magnetic block 40 using a resin material to seal the gap between the inner wall of the magnetic through hole 41 and the peripheral surface of the conductor 3. Here, a thermosetting resin with epoxy resin as the main material is used. The resin component includes an insulating portion 23 located between the inner wall of the magnetic through hole 41 and the conductor 3, a sealing insulating layer 24 covering the lower surfaces of the magnetic block 40 and the conductor 3, and a sealing insulating layer 25 covering the upper surfaces of the magnetic block 40 and the conductor 3. Alternatively, after sealing with the resin material, the thickness of the sealing insulating layers 24 and 25 can be adjusted by means of grinding or the like.

[0215] Next, as Figure 10A and Figure 10B As shown, an insulating layer 26 is formed on the lower surface of the magnetic block 40, followed by a lower conductor layer 311. Similarly, an insulating layer 27 is formed on the upper surface of the magnetic block 40, followed by a lower conductor layer 321. The insulating layers 26 and 27 are, for example, layers composed of cross-fibers of thermosetting resin and inorganic fillers or inorganic materials. In this specification, the insulating portion 21, which includes the insulating layer 26 and the sealing insulating layer 24, is referred to as the "first monomer insulating portion." Furthermore, the insulating portion 22, which includes the insulating layer 27 and the sealing insulating layer 25, is referred to as the "second monomer insulating portion."

[0216] Next, as Figure 11A and Figure 11B As shown, pattern etching is performed locally on the lower conductor layers 311 and 321 to form multiple openings. These openings are arranged to overlap with the end faces e1 and e2 of the multiple conductors 3 when viewed from above. Next, portions of the first monomer insulating portion 21 and the second monomer insulating portion 22 exposed through the openings are removed using laser drilling or the like. Thus, on the lower surface side of the magnetic block 40, through-holes 21h are formed in the first monomer insulating portion 21 and the lower conductor layer 311, exposing the first end face e1 of the conductor 3. Furthermore, on the upper surface side of the magnetic block 40, through-holes 22h are formed in the second monomer insulating portion 22 and the lower conductor layer 321, exposing the second end face e2 of the conductor 3.

[0217] Next, electroless plating and electrolytic plating are performed on the surface layers of the lower conductor layers 311 and 321 and the surface layers of the conductor 3 exposed through the vias 21h and 22h. Thus, as... Figure 12A and Figure 12BAs shown, a through-hole 21h forms a conductive conductor 33, and a conductor layer 312 is formed on the first monomer insulating portion 21. The conductor layer 312 is electrically connected to the first end face e1 of the conductor 3 through the through-hole conductor 33. The conductor layer 312 includes a lower conductor layer 311 and a plating layer. Similarly, a through-hole 22h forms a conductive conductor 34, and a conductor layer 322 is formed on the second monomer insulating portion 22. The conductor layer 322 is electrically connected to the second end face e2 of the conductor 3 through the through-hole conductor 34.

[0218] Next, conductor layers 312 and 322 are patterned into the desired shapes. Thus, as... Figure 13A and Figure 13B As shown, a plurality of first electrodes 31 are arranged at a distance from each other, formed by a conductor layer 312. Similarly, a plurality of second electrodes 32 are arranged at a distance from each other, formed by a conductor layer 322. Each first electrode 31 and a corresponding second electrode 32 are located opposite each other in the Z direction, separated by a corresponding conductor 3.

[0219] Next, as Figure 14A and Figure 14B As shown, multiple (here, six) inductor unit cells 20 are obtained by monolithizing the magnetic block 40 using a cutting machine or the like. Each inductor unit cell 20 has a conductor 3, a magnetic body 4 surrounding it, and a first electrode 31 and a second electrode 32 electrically connected to the conductor 3. Three of the six inductor unit cells 20 manufactured by this method are used as inductor unit cells 20a to 20c embedded in a circuit board.

[0220] (Embedding process)

[0221] Figures 15A-17A These are schematic top views illustrating the manufacturing method (embedding process) of the circuit board. Figures 15B-17B They are along Figures 15A-17A A schematic process cross-sectional view of the XVB-XVB~XVIIB-XVIIB lines shown.

[0222] like Figure 15A and Figure 15B As shown, a plate-shaped substrate 10 having a first surface 11 and a second surface 12 is prepared. The substrate 10 is, for example, composed of cross-fibers of thermosetting resin and inorganic filler or inorganic material. For the substrate 10, through holes (core through holes) 13a to 13c, 14, 15 and a plurality of through holes 16 are formed at predetermined positions by drilling or milling.

[0223] Next, as Figure 16A and Figure 16BAs shown, inductor units 20a to 20c are respectively arranged in through holes 13a to 13c. Similarly, a two-terminal capacitor serving as an input capacitor 5 is arranged in through hole 14, and a two-terminal capacitor serving as an output capacitor 6 is arranged in through hole 15. Core conductors 7 are respectively arranged in multiple through holes 16.

[0224] Next, as Figure 17A and Figure 17B As shown, the inductor units 20a-20c and other built-in components are sealed within the substrate 10 using the sealing member 8. The sealing member 8 is an insulating layer formed of cross-fibers composed of thermosetting resin and inorganic fillers or inorganic materials. The sealing member 8 includes a lower insulating layer 81 located on the first surface 11 of the substrate 10 and an upper insulating layer 82 located on the second surface 12. The sealing member 8 also includes an insulating portion 83 arranged to fill the gap between the inner wall of the through holes 13a-16 and the peripheral surface of each built-in component. Alternatively, the thickness of the sealing member 8 (lower insulating layer 81, upper insulating layer 82) can be adjusted by grinding or the like after the sealing member 8 is formed. In this way, a component-embedded substrate 300 is formed, incorporating the inductor units 20a-20c, capacitors 5 and 6, and core conductors 7.

[0225] (Wiring construction process)

[0226] Figures 18A-24A These are schematic top views illustrating the manufacturing method (wiring structure formation process) of a circuit board. Figures 18B-24B They are respectively with Figures 18A-24A The corresponding process bottom view. Figures 18C-24C They are along Figures 18A-24A A schematic cross-sectional view of the XVIIIC-XVIIIC~XXIVC-XXIVC lines shown.

[0227] The process of forming each wiring layer that constitutes the wiring structure includes, for example, the following processes.

[0228] (i) The process of forming the insulating layer and the underlying conductor layer;

[0229] (ii) The process of forming an opening in the lower conductor layer;

[0230] (iii) A process of removing the portion of the insulating layer located inside the opening to form a through hole;

[0231] (iv) A process of forming a via conductor by forming an upper conductor layer (e.g., plating) inside the via and on the lower conductor layer, thereby obtaining a conductor layer electrically connected to an electrode located on the opposite side of the via conductor; and

[0232] (v) A process of patterning the conductor layer to obtain a wiring layer containing multiple electrodes, wiring, terminals, etc.

[0233] <Process (i)>

[0234] First, such as Figures 18A-18C As shown, an insulating layer 101 is formed on the first surface 11 side of the substrate 300, and then a lower conductor layer 1101 made of Cu foil is formed. Similarly, an insulating layer 201 is formed on the second surface 12 side of the substrate 10, and then a lower conductor layer 2101 made of Cu foil is formed. The insulating layers 101 and 201 are, for example, layers made of thermosetting resin and inorganic fillers or cross-fibers of inorganic materials.

[0235] In this embodiment, the insulating portion (hereinafter referred to as "first insulating portion") 91 located between the lower conductor layer 1101 and each electrode (e.g., the first electrode 31a to 31c) of the built-in component includes an insulating layer 101 and a lower insulating layer 81. The insulating portion (hereinafter referred to as "second insulating portion") 92 located between the lower conductor layer 2101 and each electrode (e.g., the second electrode 32a to 32c) of the built-in component includes an insulating layer 201 and an upper insulating layer 82.

[0236] <Processes (ii) and (iii)>

[0237] Next, as Figures 19A-19C As shown, pattern etching is performed on the lower conductor layers 1101 and 2101 to form multiple openings (step (ii)). Then, the portions of the first insulating portion 91 and the second insulating portion 92 exposed through the openings are removed using laser drilling or the like (step (iii)). As a result, multiple through-holes 91h are formed on the first surface 11 side of the substrate 10 in the first insulating portion 91 and the lower conductor layer 1101. Each through-hole 91h partially exposes the electrode on the first surface 11 side of the corresponding built-in component. Furthermore, multiple through-holes 92h are formed on the second surface 12 side of the substrate 10 in the second insulating portion 92 and the lower conductor layer 2101. Each through-hole 92h partially exposes the electrode on the second surface 12 side of the corresponding built-in component.

[0238] <Process (iv)>

[0239] Next, electroless plating and electrolytic plating are performed on the surface layers of the lower conductor layers 1101 and 2101 and the portions of the electrodes of the built-in components exposed through the vias 91h and 92h. Thus, as... Figures 20A-20CAs shown, multiple through-hole conductors v1 are formed within the through-hole 91h, and a conductor layer 1102 is formed on the first insulating portion 91. The conductor layer 1102 is electrically connected to each built-in component through the through-hole conductors v1. Similarly, multiple through-hole conductors v2 are formed within the through-hole 92h, and a conductor layer 2102 is formed on the second insulating portion 92. The conductor layer 2102 is electrically connected to each built-in component through the through-hole conductors v2.

[0240] <Process (v)>

[0241] Next, conductor layers 1102 and 2102 are patterned into the desired shapes (process (v)). For example... Figures 21A-21C As shown, by patterning the conductor layer 1102, a wiring layer 110 containing multiple electrodes, including a first connection electrode 111, a first inductor connection electrode 112, and a first input capacitor connection electrode 113, is obtained. Similarly, by patterning the conductor layer 2102, a wiring layer 210 containing multiple electrodes, including a second inductor connection electrode 211, a second connection electrode 212, a second input capacitor connection electrode 213, and an output capacitor connection electrode 214, is obtained.

[0242] <Formation of wiring layers 120, 130, 220, and 230>

[0243] After that, as Figure 22A and Figure 22B As shown, wiring layer 120 is formed on wiring layer 110 with insulating layer 102 in between, and wiring layer 220 is formed on wiring layer 210 with insulating layer 202 in between, through the same process as in processes (i) to (v) above. Wiring layer 120 and wiring layer 220 each include a plurality of electrodes having a desired pattern.

[0244] Next, as Figure 23A and Figure 23B As shown, through the same process as the above-described processes (i) to (v), a wiring layer 130 is formed on the wiring layer 120 with an insulating layer 103 in between, and a wiring layer 230 is formed on the wiring layer 220 with an insulating layer 203 in between.

[0245] In this embodiment, such as Figure 23B As shown, wiring layer 130 has terminal sections such as control terminal CTL, input terminal Vin, output terminal Vout, and ground terminal GND. Figure 23A As shown, wiring layer 230 has the terminals of the switching element SW (SW_Vin, SW_Vout, SW_GND, and SW-CTL) (see reference). Figure 6 The terminal pads Ld_SW_Vin, Ld_SW_Vout, Ld_SW_GND, and Ld_SW-CTL are for SW.

[0246] <Formation of solder mask>

[0247] Next, as Figure 24A and Figure 24B As shown, a solder mask 105 is formed on wiring layer 130, and a solder mask 205 is formed on wiring layer 230. Solder mask layers 105 and 205 each have openings that expose the pads of wiring layers 130 and 230. Alternatively, the surfaces (conductor surfaces) of the portions of wiring layers 120 and 230 exposed through the openings of solder mask layers 105 and 205 may undergo NiAu-based anti-corrosion, anti-rust, or other surface treatments. This is how the circuit board 1 is manufactured.

[0248] [Effect]

[0249] First, for comparison, a reference example of a magnetic core assembly with an inductor (vertical inductor) incorporating current flowing in the thickness direction will be described. Figure 46 This is a schematic cross-sectional view of the magnetic core assembly 700, a reference example made by the inventors with reference to the description in Patent Document 1. In the magnetic core assembly 700 of the reference example, two inductors 710 and 720 are formed by arranging a U-shaped conductor 702 that extends through the magnetic core 701 in the thickness direction. The inductors 710 and 720 are connected in parallel. With this configuration, in order to achieve the desired inductance value, there is a situation where the conductor 702 becomes taller, resulting in the magnetic core assembly 700 becoming thicker.

[0250] In addition, Figure 46 In the example shown, the following problems may arise: The magnetic core assembly 700 is electrically and mechanically connected to the upper and lower printed circuit boards 703 and 705 via soldering or the like. Specifically, the upper end of the conductor 702 is connected to the bonding pad 704 of the printed circuit board 703 using solder. The lower end (bent portion) of the conductor 702 is connected to the bonding pad 706 of the printed circuit board 705 using solder. In such a configuration, the presence of a bend makes miniaturization difficult. Moreover, in such a configuration, the connection between components sometimes becomes a localized connection (the connection portions between components are discretely arranged, and air gaps exist between components). As a result, mechanical stress concentrates at the connection points between components, potentially reducing connection reliability.

[0251] In contrast, according to this embodiment, an inductor 2 is built into the circuit board 1, thus... Figure 46 Compared to the structure shown where printed circuit boards are arranged on both sides of the inductor, a smaller and thinner voltage regulation module can be formed.

[0252] Furthermore, according to the circuit board 1 of this embodiment, a vertical inductor that flows current in the thickness direction (the direction perpendicular to the circuit surface) can be divided into three or more components within the substrate 10. The bending portion as in the reference example is also unnecessary. Therefore, the substrate 300 containing the component can be further thinned while ensuring the desired inductance value. Thus, by using this circuit board 1, the voltage regulation module can be further thinned.

[0253] Furthermore, according to the circuit board 1 of this embodiment, the inductors 2 (inductor units 20a-20c) are surface-fixed to the wiring layers 110 and 210 via insulating portions 91 and 92, thus... Figure 46 Compared to the construction of the reference example shown, the mechanical connection stability of inductor 2 can be significantly improved.

[0254] In the circuit board 1 of this embodiment, the number of inductor units constituting the inductor 2 (the number of conductors 3a to 3c) is three. This makes it easy to connect one of the input and output terminals of the inductor 2 to the electrode on the first surface 11 side of the substrate 10, and the other to the electrode on the second surface 12 side. Therefore, when the circuit board 1 is applied to a voltage regulation module (see reference...), Figure 45 This shortens the path from the switch output terminal SW_Vout to the input terminal of inductor 2 and the path from the output terminal of inductor 2 to the output terminal Vout of the module. As a result, the resistance of the voltage regulation module can be reduced, thus improving the efficiency of the voltage regulation module.

[0255] Furthermore, the circuit board 1 shown in the figure includes three inductor units, but the number of inductor units can be more than one and is not particularly limited. The number of inductor units is preferably odd. If it is odd, it is easier to connect the input and output terminals of inductor 2 to the wiring layers located on opposite sides of each other across the substrate 10. Therefore, if the circuit board 1 is applied to a voltage regulation module, the current path other than that of inductor 2 can be shortened.

[0256] In the circuit board 1 of this embodiment, the first electrodes 31a-31c and the second electrodes 32a-32c (collectively referred to as "inductor electrodes") of the inductor units 20a-20c are arranged such that they overlap at least partially with the corresponding conductors and magnetic bodies when viewed from above. This allows for the arrangement of multiple conductive paths for connection to electrodes within wiring layers 110 and 210 on each inductor electrode, thereby increasing the connection area. Consequently, connection resistance can be reduced, and connection reliability can be improved.

[0257] According to this embodiment, by making the inductor electrodes larger than the conductors when viewed from above, multiple conductive paths connecting the first electrodes 31a and 31b to the first connecting electrode 111 can be arranged in an area larger than the end faces of conductors 3a and 3b when viewed from above. Alternatively, at least one conductive path can be located outside the corresponding conductor 3a or 3b when viewed from above. Similarly, multiple conductive paths connecting the second electrodes 32b and 32c to the second connecting electrode 212 can be arranged in an area larger than the end faces of conductors 3a and 3b when viewed from above. As a result, the connection resistance between inductor units can be reduced, and therefore the DC resistance of the inductor 2 composed of inductor units 20a to 20c can be reduced.

[0258] The circuit board 1 of this embodiment includes at least one two-terminal capacitor 5, 6 located inside the substrate 10. The at least one two-terminal capacitor 5, 6 and the inductor 2 are arranged side by side in a direction intersecting the Z direction. By using such a circuit board 1, a further reduction in the thinness of the voltage regulation module can be achieved compared to a structure in which capacitors and inductors are arranged in the thickness direction (e.g., Patent Document 1).

[0259] The two-terminal capacitor (e.g., input capacitor 5) of this embodiment includes a dielectric 53, a lower electrode 51 located on the first surface 11 side of the dielectric 53, and an upper electrode 52 located on the second surface 12 side of the dielectric 53. The lower electrode 51 is electrically connected to wiring in the first wiring layer 110 via a conductor provided in the first insulating portion 91. The upper electrode 52 is electrically connected to wiring in the second wiring layer 210 via a conductor provided in the second insulating portion 92. With this structure, the connection resistance between each electrode of the two-terminal capacitor and the wiring layer can be reduced, and the connection reliability can be improved.

[0260] Furthermore, the circuit board of the present invention is not limited to Figures 1-24C The illustrated embodiment can be implemented in various other ways. For example, one or both of the input capacitor and the output capacitor may not be disposed inside the substrate 10. Alternatively, two or more inductors 2 may be built into the substrate 10. Furthermore, the layout of the built-in components of the substrate 10, the circuit structure of the circuit board 1, the number of wiring layers of the circuit board 1, the electrode patterns in the wiring layers, etc., are not limited to the illustrated example and can be appropriately selected.

[0261] Furthermore, in the above embodiments, a single conductor carrying a magnetic material is arranged in each inductor unit 20a to 20c. However, two or more conductors carrying a magnetic material may also be arranged within one inductor unit. These conductors may also be arranged at a distance from each other and connected in parallel through inductor electrodes. That is, an inductor unit may also be composed of two or more inductors connected in parallel.

[0262] As described above, each inductor unit functions as an inductor individually. Therefore, by connecting the three conductors 3a to 3c in parallel, three inductors can be constructed from the conductors 3a to 3c and the magnetic bodies 4a to 4c. In this case, all of the first electrodes 31a to 31c can be electrically connected to the first connecting electrode 111, and all of the second electrodes 32a to 32c can be electrically connected to the second connecting electrode 212.

[0263] Implementation Method 2

[0264] The circuit board of the second embodiment differs from the circuit board of the first embodiment in that the three inductor units are integrally formed. Hereinafter, the differences from the circuit board of the first embodiment will be mainly described, and repeated descriptions will be omitted as appropriate.

[0265] Figure 25A and Figure 25B These are schematic top and bottom views, respectively, showing the component-embedded substrate and part of the wiring layer of the circuit board in this embodiment. Figure 25C It is along Figure 25A and Figure 25B A schematic cross-sectional view of the XXVC-XXVC line. Figure 25C It also indicates wiring layer 110 and wiring layer 210. In Figure 25A and Figure 25B In the diagram, for ease of understanding, the electrodes within wiring layers 210 and 110 are represented by double-dotted lines.

[0266] Component built-in substrate 300a and Figures 3A-3C The difference between the component and the embedded substrate 300 shown is that the inductor 2 is disposed as a single component within a single through-hole 13 of the substrate 10. Furthermore, the inductor 2 in this embodiment is similar to... Figures 3A-3C The difference in the inductor 2 shown is that the magnetic bodies 4a to 4c are integrally formed (connected), and the two first electrodes 31a and 31b are integrally formed and the two second electrodes 32b and 32c are integrally formed.

[0267] The inductor 2 includes a magnetic layer 4L, conductors 3a to 3c, first electrodes 31ab and 31c, and second electrodes 32a and 32bc.

[0268] The magnetic layer 4L is a long rectangular parallelepiped in the X direction. Three magnetic through-holes 41, spaced apart when viewed from above, are provided in the magnetic layer 4L. Conductors 3a to 3c are respectively disposed in the magnetic through-holes 41. The portions 4a to 4c of the magnetic layer 4L located around the peripheral surfaces of conductors 3a to 3c become the magnetic substrate of inductor unit cells 20a to 20c. The magnetic bodies 4a to 4c are continuous (connected), and no partition walls of the substrate 10 are disposed between adjacent magnetic bodies.

[0269] Electrode 31ab is Figures 3A-3C The first electrodes 31a and 31b are integrally formed. The first electrode 31ab is disposed at a distance from the first electrode 31c on the first surface 11 side of the magnetic layer 4L. The first electrode 31ab is electrically connected to the first ends of the conductors 3a and 3b. The first electrode 31ab is electrically connected to the first connecting electrode 111 via a through conductor in the first insulating portion 91.

[0270] The second electrode 32bc is Figures 3A-3C The second electrodes 32b and 32c are integrally formed. The second electrode 32bc is disposed at a distance from the second electrode 32a on the second surface 12 side of the magnetic layer 4L. The second electrode 32bc is electrically connected to the second ends of the conductors 3b and 3c. The second electrode 32bc is electrically connected to the second connecting electrode 212 via a through conductor in the second insulating portion 92.

[0271] In the illustrated example, the first electrode 31ab overlaps entirely with conductors 3a and 3b when viewed from above. Alternatively, the first electrode 31ab may be smaller than the first connecting electrode 111 when viewed from above, and located inside the outline of the first connecting electrode 111. Similarly, the second electrode 32bc overlaps entirely with conductors 3b and 3c when viewed from above. Alternatively, the second electrode 32bc may be located inside the outline of the second connecting electrode 212 when viewed from above.

[0272] [Manufacturing method of circuit board]

[0273] The manufacturing method of the circuit board 1 in this embodiment is similar to that of the reference. Figures 7A to 24C The manufacturing method described is the same as that of the first embodiment. Hereinafter, only the differences from the first embodiment will be described, and repeated descriptions will be omitted.

[0274] Figure 26A and Figure 27A These are schematic top views illustrating the manufacturing process of a single inductor unit. Figure 28A and Figure 29A These are schematic top views illustrating the manufacturing method (embedding process) of the circuit board. Figures 26B to 29B They are along Figures 26A to 29AThe schematic process cross-sectional view of the XXVIB-XXVIB and XXIXB-XXIXB lines shown.

[0275] First, by referring to Figures 7A to 12B The same method is used to form conductor layers 312 and 322, and to pattern conductor layers 312 and 322. In this embodiment, as... Figure 26A and Figure 26B As shown, a first electrode 31ab connected to conductors 3a and 3b and a first electrode 31c connected to conductor 3c are formed by conductor layer 312. Additionally, a second electrode 32a connected to conductor 3a and a second electrode 32bc connected to conductors 3b and 3c are formed by conductor layer 322. Then, as... Figure 27A and Figure 27B As shown, the magnetic block 40 is cut. Here, the magnetic layer 4L is cut out in such a way that it includes the conductors 3a to 3c and the surrounding magnetic bodies 4a to 4c. In this way, an inductor 2 containing inductor units 20a to 20c is obtained.

[0276] Next, as Figure 28A and Figure 28B As shown, a substrate 10 is prepared to have a through-hole 13 in the inductor configuration area. Then, as... Figure 29A and Figure 29B As shown, an inductor 2 obtained by the above method is disposed within the through hole 13. Predetermined components are also disposed in through holes 14 to 16, and sealed using the sealing member 8. Subsequent procedures are the same as in the first embodiment.

[0277] [Effect]

[0278] In the circuit board 1 of this embodiment, the magnetic bodies 4a to 4c of multiple inductor unit cells 20a to 20c are integrally formed, thereby reducing the area of ​​the inductor forming region of the substrate 10. Therefore, miniaturization of the circuit board 1 can be achieved.

[0279] Furthermore, since the first electrode of each inductor unit 20a and 20b is integrally formed, and the second electrode of each inductor unit 20b and 20c is integrally formed, the connection resistance between the inductor units can be reduced. Therefore, the DC resistance of inductor 2 can be reduced. As a result, the resistive losses of the circuit can be further reduced.

[0280] exist Figures 25A-25C In the example shown, three inductor units 20a to 20c are integrally formed, but two of them can also be integrally formed. Alternatively, more than three inductor units can be integrally formed.

[0281] In this embodiment, each inductor unit 20a-20c may also have two or more conductors connected in parallel. Alternatively, three inductors may be formed by connecting conductors 3a-3c in parallel and magnetic bodies 4a-4c.

[0282] Third Implementation Method

[0283] (The foundational insights)

[0284] The goal is to further reduce the area of ​​circuit boards that incorporate components such as vertical inductors. "Circuit board area" refers to the area viewed along the thickness direction of the board. For example, when two or more vertical inductors are incorporated, the area of ​​the circuit board tends to increase. In particular, as in the first embodiment, when a vertical inductor is divided into multiple inductor units and incorporated, the area of ​​the circuit board tends to increase if the number of inductor units (i.e., the number of conductors connected in series to form an inductor) increases. Furthermore, not limited to the conductors constituting the inductor, the area of ​​the circuit board also increases when conductors constituting other components, such as transformer components utilizing magnetic coupling of conductors, are incorporated.

[0285] Therefore, the inventors investigated a structure that could further reduce the area of ​​a circuit board containing multiple conductors by suppressing the increase in area. As a result, it was discovered that miniaturization of the circuit board can be achieved by arranging multiple conductors spaced apart from each other in a through-hole in the substrate. The following embodiments are based on this new insight.

[0286] [Overall structure of the circuit board]

[0287] The circuit board of this embodiment is similar to that of the first embodiment, including a first wiring structure and a second wiring structure, and a component-embedded substrate located between these wiring structures. The component-embedded substrate includes at least one conductor-containing portion between the first wiring structure and the second wiring structure. The "conductor-containing portion" includes a substrate and a plurality of conductors disposed in through-holes in the substrate. Each conductor disposed in the through-hole may also be a conductor constituting a component such as an inductor. The substrate having the through-holes may, for example, be a substrate disposed inside a core substrate (e.g., a magnetic substrate or a magnetic layer).

[0288] [Structure of a conductor containing a part]

[0289] Hereinafter, with reference to the accompanying drawings, an example of a conductor-containing portion of the circuit board according to this embodiment will be described. The following description will take a conductor-containing portion constituting an inductor component as an example.

[0290] Figure 30This is a schematic perspective view of the conductor-containing portion of the circuit board according to the third embodiment. Figure 31A yes Figure 30 A schematic top view of a conductor containing a portion. Figure 31B It is along Figure 31A A schematic cross-sectional view of the XXXIB-XXXIB line.

[0291] The conductor-containing portion 800 includes a substrate 810, conductors 831 and 832, and an insulating layer 840. In this example, the substrate 810 is a magnetic material.

[0292] The substrate 810 has a first surface 811 and a second surface 812 located on the side opposite to the first surface 811 in the thickness direction (Z direction). Although not shown, a first wiring layer is disposed on the first surface 811, and a second wiring layer is disposed on the second surface 812. The substrate 810 has a through hole 820 extending in the thickness direction. In the illustrated example, the substrate 810 is, for example, a quadrangular prism (here, a cuboid). The through hole 820 is, for example, cylindrical.

[0293] In a top view (hereinafter, sometimes simply referred to as "top view") along the Z direction, conductors 831 and 832 are disposed at a distance from each other within the through-hole 820. Conductors 831 and 832 extend in the Z direction. The ends (first ends) of conductors 831 and 832 on the first surface 811 side are electrically connected to the corresponding electrodes in the first wiring layer. The ends (second ends) of conductors 831 and 832 on the second surface 812 side are electrically connected to the corresponding electrodes in the second wiring layer.

[0294] The insulating layer 840 is located between conductors 831 and 832 when viewed from above. The insulating layer 840 isolates conductors 831 and 832 from each other within the through hole 820.

[0295] In this specification, the structure M consisting of a plurality of conductors disposed in a through-hole and an insulating layer for isolating the conductors from each other is referred to as the "first structure". The specific construction of the first structure M will be described later.

[0296] An insulating portion 860 is disposed between the inner wall of the through hole 820 and the first structure M. The insulating portion 860 is, for example, a resin component. The insulating portion 860 may also be disposed in such a way that it fills the gap between the inner wall of the through hole 820 and the side surface of the first structure M. The insulating portion 860 may also contain a magnetic material. As a result, the inductance of the inductor component using the conductor-containing portion 800 and each conductor 831, 832 can be improved.

[0297] (Construction M, 1st type)

[0298] The conductors 831 and 832 of the first structure M are columnar extending in the Z direction. For example, conductors 831 and 832 may also be polygonal prisms with a cross-section of a polygon having an interior angle of 90° or more but less than 180°. In this specification, "cross-section of the conductor" refers to the cross-section of the conductor orthogonal to the Z direction (the thickness direction of the substrate). In this example, conductors 831 and 832 are constructed in a manner where their dimensions are equal and their shapes are identical, but the dimensions and shapes (cross-sectional shapes) of conductors 831 and 832 may also differ.

[0299] exist Figures 30-31B In the example shown, conductors 831 and 832 are both tetragonal prisms with rectangular cross-sections. Conductors 831 and 832 are arranged in the Y direction separated by an insulating layer 840. In this example, the distance between conductors 831 and 832 is small, and conductors 831 and 832 are arranged close to each other. Preferably, the distance between conductors 831 and 832 (here, the length of the insulating layer 840 in the Y direction) is set to a minimum spacing that ensures sufficient electrical withstand voltage for the potential difference generated between conductors 831 and 832. This can improve the coupling coefficient between conductors or achieve miniaturization of components or circuit boards. The distance between conductors 831 and 832 is, for example, 60 μm or less.

[0300] Conductor 831 has a first side surface 831a opposite to conductor 832 and a second side surface 831b located on the opposite side of the first side surface 831a in the Y direction. Similarly, conductor 832 has a first side surface 832a opposite to conductor 831 and a second side surface 832b located on the opposite side of the first side surface 832a in the Y direction. The first side surface 831a of conductor 831 and the first side surface 832a of conductor 832 may also be bonded together by an insulating layer 840.

[0301] At least a portion of the sides of conductors 831 and 832 may also be covered by the insulating layer 850. "Side of conductor" refers to the portion of the conductor's surface between the end face on the first side and the end face on the second side. In the illustrated example, the second side 831b of conductor 831 and the second side 832b of conductor 832 are covered by the insulating layer 850. Alternatively, the sides of conductors 831 and 832 extending along the Y direction when viewed from above may not be covered by the insulating layer 850, for example, and may be in direct contact with the insulating portion 860.

[0302] exist Figures 30-31B In the example shown, the first structure M is a quadrangular prism. Viewed from above, the first structure M has a quadrilateral shape that is slightly smaller than the quadrilateral inscribed within the circular opening of the through-hole 820. With this structure, when manufacturing the conductor-containing portion 800, the separately formed first structure M can be more easily configured within the through-hole 820 of the substrate 810.

[0303] [Effect]

[0304] The circuit board in this embodiment includes: a substrate 810 having a through-hole 820 extending in the thickness direction (Z direction); conductors 831 and 832 disposed in the through-hole 820 and extending in the Z direction; and an insulating layer 840 that isolates the conductors 831 and 832 in the through-hole 820. With this structure, compared to providing a through-hole for each conductor, the area of ​​the circuit board when viewed along the Z direction can be reduced. Therefore, miniaturization of the circuit board is possible.

[0305] In the circuit board of this embodiment, conductors 831 and 832 are electrically isolated from each other. For example, the first ends of conductors 831 and 832 may be electrically connected to different electrodes on the first surface 811, and the second ends of conductors 831 and 832 may be electrically connected to different electrodes on the second surface 812. Thus, conductors 831 and 832 can form parts of mutually different components.

[0306] The circuit board of this embodiment may also include a first inductor and a second inductor that can operate independently of each other. In this case, the first inductor may include a conductor 831 and the second inductor may include a conductor 832.

[0307] The first and second inductors can be constructed from a single conductor-containing portion 800, or from multiple conductor-containing portions 800 as described later. When the first and second inductors are constructed from multiple conductor-containing portions 800, the conductors 831 of the multiple conductor-containing portions 800 can be connected in series to form the first inductor, and the conductors 832 can be connected in series to form the second inductor. With this structure, the conductors of the vertically oriented inductors can be arranged separately, thus allowing for a thinner circuit board. Furthermore, by arranging two or more conductors 831 and 832 in a single through-hole, the area of ​​the circuit board can be reduced. Therefore, further miniaturization of the circuit board is possible.

[0308] In addition, conductors 831 and 832 can also be electrically connected. For example, the first ends of conductors 831 and 832 can be interconnected by electrodes disposed on the first surface 811, and the second ends of conductors 831 and 832 can be interconnected by electrodes disposed on the second surface 812.

[0309] (Variation Example 1)

[0310] Figure 32A This is a schematic top view of a modified example 1 of a conductor containing a portion. Figure 32B It is along Figure 32A A schematic cross-sectional view of the XXXIIB-XXXIIB line.

[0311] Figure 32A and Figure 32B The conductor shown in Modified Example 1 contains part 801 and Figure 31A and Figure 31B The difference in the conductor containing part 800 shown is that, when viewed from above along the Z direction, the through hole 820 is not circular, but has a shape that is longer in one direction (the X direction in this example).

[0312] In this modified example, the opening shape of the through hole 820 is a long track shape (elongated oval) in the X direction. "Opening shape of the through hole" refers to the shape when the cylindrical through hole is viewed from the Z direction, specifically the shape of the opening on the first surface 811 and the second surface 812 of the substrate 810. "Track shape" refers to a shape, such as a racing track shape, where the two shorter sides of a rectangle are replaced by outwardly protruding partial circles or semicircles, or similar shapes. Such a through hole 820 is composed of a quadrangular prism region Pa and two partially cylindrical regions Pb located on either side of the quadrangular prism region Pa in the Y direction. The quadrangular prism region Pa and the partially cylindrical regions Pb correspond to the rectangular portion located in the center of the track shape when viewed from above and the two partially circular portions located on either side of it, respectively.

[0313] exist Figure 32A and Figure 32B In the example shown, both the first structure M and the through hole 820 have a shape that is longer in one direction (X direction) when viewed from above. Alternatively, when viewed from above, the maximum length Ly of the through hole 820 in the width direction (Y direction) is smaller than the maximum length w of the first structure M in the length direction. Therefore, when manufacturing the conductor containing portion 801, the first structure M can be arranged in the through hole 820 with a predetermined orientation. Specifically, the first structure M is arranged in the through hole 820 with the through hole 820 and the first structure M having the same or substantially the same orientation in the length direction when viewed from above. In this example, the first structure M is arranged in the through hole 820 such that the conductors 831 and 832 are arranged in the Y direction (i.e., the conductor 831 is located on the -Y side or +Y side of the conductor 832).

[0314] The first structure M1 is disposed, for example, inside the prism region Pa of the through hole 820. The first structure M may also have a rectangular shape that is smaller than the prism region Pa of the through hole 820 when viewed from above. The length of the through hole 820 in the Y direction is the largest in the prism region Pa (length Ly), and decreases as it moves away from the prism region Pa along the X direction. Therefore, when viewed from above, as long as the first structure M has a shape that is smaller than the prism region Pa, the position of the first structure M in the through hole 820 is unlikely to deviate from the prism region Pa.

[0315] Conductors 831 and 832 can also have the same shape and size. The first structure M can also be configured in a point-symmetrical manner, with the center of the insulating layer 840 as the center of symmetry when viewed from above along the Z direction. According to such a structure, even when conductors 831 and 832 are relative to... Figure 32A Even when the orientation is rotated 180° and the vertical arrangement is reversed (conductor 831 is arranged on the +Y side of conductor 832), it is also possible to obtain a configuration with the same characteristics as shown. Figure 32A Conductors with essentially the same structure and function contain part 801.

[0316] According to the circuit structure of Modified Example 1, the through-hole 820 has an opening shape that is longer in one direction. Therefore, during the manufacturing process of the conductor-containing portion 801, when the first structure M is placed in the through-hole 820, the orientation of the first structure M relative to the through-hole 820 is determined. Therefore, it is easy to place each conductor 831, 832 in a predetermined position. As a result, each conductor 831, 832 can be more reliably connected to predetermined electrodes in the wiring layer. Therefore, it is easier to manufacture the circuit board.

[0317] Furthermore, in Modified Example 1, polygonal conductors 831 and 832 are disposed in the through-hole 820 with a racetrack-shaped opening. Therefore, compared to the case with a circular opening, the cross-sectional area of ​​conductors 831 and 832 can be increased. Thus, the resistance of conductors 831 and 832 can be reduced while suppressing the increase in the area of ​​the circuit board.

[0318] (Variation Example 2)

[0319] Figure 33A This is a schematic top view of a modified example 2 of a conductor containing a portion. Figure 33B It is along Figure 33A A schematic cross-sectional view of the XXXIIIB-XXXIIIB line.

[0320] Figure 33A and Figure 33B The conductor shown in Modified Example 2 contains part 802 and Figure 32A and Figure 32B Compared to conductor-containing portion 801, conductors 831 and 832 have different cross-sectional shapes. The through-hole 820 of conductor-containing portion 802 has a racetrack-shaped opening.

[0321] In the conductor-containing portion 802, the conductor 831 is configured such that its width in the X direction decreases as it moves away from the conductor 832 along the Y direction. The width w1 of the portion of the conductor 831 closest to the conductor 832 along the X direction is larger than the width w2 of the portion farthest from the conductor 832 along the X direction. Width w1 is, for example, the length of the first side surface 831a in the X direction, and width w2 is, for example, the length of the second side surface 831b in the X direction. The conductor 832 is also configured in the same way as the conductor 831, such that its width in the X direction decreases as it moves away from the conductor 831 along the Y direction.

[0322] Conductors 831 and 832 can also be polygonal prisms (in this case, quadrangular prisms). Alternatively, when viewed from above, conductors 831 and 832 can be polygonal, having a first side located on the side of the insulating layer 840 and a second side adjacent to the first side, with angles c1 and c2 between the first and second sides being acute angles. Figure 33A and Figure 33B In the example shown, when viewed from above, conductors 831 and 832 are trapezoidal in shape, with the first side being the lower base of the trapezoid and the second side being the leg of the trapezoid. Conductors 831 and 832 constitute a first structure M that is approximately hexagonal prism in shape.

[0323] The first structural member M is positioned within the through-hole 820 such that, in a top view, the length direction of the first structural member M is approximately aligned with that of the through-hole 820. The maximum width w1 of the first structural member M in the X direction is greater than the length in the X direction of the prism region Pa of the through-hole 820. Therefore, as... Figure 33A As shown, when viewed from above, the first structure M extends from the quadrangular prism region Pa into the interior of the local cylindrical regions Pb on both sides.

[0324] At least a portion of the sides of conductors 831 and 832 may also be covered by insulating layer 850. In the illustrated example, the entire sides of each conductor 831 and 832, except for the first side surfaces 831a and 832a, are covered by insulating layer 850.

[0325] In the circuit board of Modified Example 2, at least one (in this case, both) of conductors 831 and 832 is configured such that its width in the X direction decreases as it moves away from the other conductor along the Y direction. As a result, the magnetic field f generated around each conductor 831 and 832 is not easily blocked by the corners of conductors 831 and 832, and is easy to rotate.

[0326] Furthermore, according to the circuit board of Modified Example 2, the first structure M can extend from the prism region Pa to the local cylindrical region Pb. Therefore, when viewed from above, the proportion of the area occupied by the first structure M in the through-hole 820 can be larger than that in Modified Example 1, for example. Therefore, while suppressing the increase in the area of ​​the circuit board, the cross-sectional area of ​​the conductors 831 and 832 can be increased, further reducing the resistance. In addition, the gap between the inner wall of the through-hole 820 and the first structure M can be further reduced, thus reducing the volume of the insulating portion 860 filling the area around the conductors 831 and 832. As a result, the inductance can be further improved.

[0327] (Variation Example 3)

[0328] Figure 34A This is a schematic top view of variation 3 of the conductor containing a portion. Figure 34B It is along Figure 34A A schematic cross-sectional view of the XXXIVB-XXXIVB line.

[0329] exist Figure 34A and Figure 34B In the conductor-containing portion 803 of the modified example 3 shown, the conductors 831 and 832 differ from the aforementioned conductor-containing portions 800-802 in that, when viewed from above, they have different shapes from each other. In this modified example, the first structure M and the through hole 820 have asymmetrical shapes when viewed from above.

[0330] Conductor 831 is with Figure 33A and Figure 33B The conductor 831 in the modified example shown is also columnar (here, a quadrangular prism), constructed such that its width in the X direction decreases with distance from conductor 832. Conductor 832 and... Figure 31A and Figure 31B The conductor 831 shown is also a quadrangular prism with a rectangular cross-section. The cross-sectional area of ​​conductor 832 is larger than that of conductor 831. In the through-hole 820, the first side surface 831a of conductor 831 and the first side surface 832a of conductor 832 are opposite each other in the Y direction separated by an insulating layer 840. The width w3 in the X direction of conductor 832 (here, the length of the first side surface 832a) is, for example, larger than the maximum width w1 in the X direction of conductor 831 (here, the length of the first side surface 831a in the X direction).

[0331] The through hole 820 has a configuration in which two cylindrical holes (hereinafter referred to as "first hole" and "second hole") penetrating the substrate 810 in the Z direction are arranged in a partially overlapping manner. The through hole 820 has a first region Pc1 defined by the inner wall of the first hole and a second region Pc2 defined by the inner wall of the second hole.

[0332] exist Figure 34A and Figure 34B In the example shown, the second hole has a larger radius than the first hole. Viewed from above, the area of ​​the second region Pc2 is larger than that of the first region Pc1. Conductor 832 is located, for example, inside the second region Pc2. Alternatively, viewed from above, conductor 832 may be a quadrilateral shape smaller than the quadrilateral inscribed in the partially circular second region Pc2. At least a portion of conductor 831 is located inside the first region Pc1. Conductor 831 may also extend from the first region Pc1 to the second region Pc2. For the design method of the through hole 820 and conductors 831 and 832 in this modified example, refer to... Figure 44A Then it will be discussed.

[0333] In the circuit board of Modified Example 3, the through-hole 820 has an asymmetrical shape when viewed from above, and the first structure M also has an asymmetrical shape corresponding to the through-hole 820. Based on this structure, the orientation of the first structure M disposed in the through-hole 820 is uniquely determined. Therefore, it is easy to place each conductor 831, 832 in a predetermined position. As a result, conductors 831, 832 can be more reliably connected to predetermined electrodes within the wiring layer. Therefore, it is easier to manufacture the circuit board.

[0334] Furthermore, in the circuit board of Modified Example 3, the cross-sectional areas of conductors 831 and 832 are different from each other, which is advantageous when the current ratios of conductors 831 and 832 are different. For example, by placing a conductor 832 with a larger cross-sectional area in the line through which a larger current flows, the resistance of that line can be suppressed to be lower.

[0335] Furthermore, in Modification 3, conductor 831 is configured such that its width in the X direction decreases as it moves away from conductor 832. As a result, the magnetic field generated around conductors 831 and 832 is less likely to be blocked by conductor 831, thus increasing the inductance.

[0336] Furthermore, in Modification 3, the through-hole 820 has a structure in which two cylindrical holes corresponding to conductors 831 and 832 are arranged in a partially overlapping manner, so that the magnetic field (magnetic flux) generated around each conductor 831 and 832 can easily pass through the magnetic material (substrate 810). Therefore, the inductance can be further improved.

[0337] (Variation Example 4)

[0338] Figure 35A This is a schematic top view of variation 4 of the conductor containing a portion. Figure 35B It is along Figure 35A A schematic cross-sectional view of the XXXVB-XXXVB line.

[0339] Figure 35A and Figure 35BThe conductor-containing portion 804 shown in Modified Example 4 is similar to the three conductors 831-833 including the through hole 820 disposed in the substrate 810 at this point. Figure 34A and Figure 34B The first construct M in the modified example 3 shown is different.

[0340] In the conductor-containing portion 804, in the through hole 820, a conductor 833 is disposed on the side of conductor 832 opposite to conductor 831. Conductors 831 to 833 are arranged sequentially in the Y direction, for example, within the through hole 820.

[0341] The insulating layer 840 includes a first insulating layer 841 located between conductors 831 and 832 and a second insulating layer 842 located between conductors 832 and 833.

[0342] In the illustrated example, conductor 833 is a polygonal prism (in this case, a quadrangular prism), and the first side 833a of conductor 833 located on the side of conductor 832 and the second side 832b of conductor 832 are opposite each other in the Y direction through the second insulating layer 842.

[0343] Conductor 832 may also have the same shape as conductor 833. As shown, the width of conductor 833 in the X direction may also decrease as it moves away from conductor 831. Alternatively, the maximum width of conductor 833 in the X direction (here, the length of the first side 833a in the X direction) may be smaller than the width w3 of conductor 832 in the X direction, for example, the same as the width of conductor 831 in the X direction.

[0344] Alternatively, the Y-direction length u2 of conductor 832 can be larger than the Y-direction lengths u1 and u3 of conductors 831 and 833, respectively. This structure allows a larger current to flow in conductor 831, which has a larger cross-sectional area. For example, the Y-direction length u2 of conductor 832 could be 0.8 mm, while the Y-direction lengths u1 and u3 of conductors 831 and 833 could each be 0.2 mm.

[0345] The through-hole 820 has a configuration in which three cylindrical holes (hereinafter referred to as "the first hole", "the second hole", and "the third hole") penetrating the substrate 810 in the Z direction are arranged in a partially overlapping manner. In this example, the through-hole 820 has a configuration in which the first hole is arranged to partially overlap with one end of the second hole in the Y direction and the third hole is arranged to partially overlap with the other end of the second hole. The through-hole 820 has a first region Pc1 defined by the inner wall of the first hole, a third region Pc3 defined by the inner wall of the third hole, and a second region Pc2 located between the first region Pc1 and the third region Pc3 and defined by the inner wall of the second hole.

[0346] exist Figure 35A and Figure 35B In the example shown, the radius of the second hole is larger than the radii of the first and third holes. Therefore, the maximum width in the X direction of the second region Pc2 is larger than the maximum width in the X direction of the first region Pc1 and the third region Pc3. Alternatively, when viewed from above, the area of ​​the second region Pc2 is larger than that of the first region Pc1 and the third region Pc3. Conductor 832 is located inside the second region Pc2. At least a portion of conductor 831 is located inside the first region Pc1, and at least a portion of conductor 833 is located inside the third region Pc3.

[0347] Alternatively, both the through-hole 820 and the first structure M may have a shape that is longer in one direction (in this case, the Y direction). Alternatively, the maximum length of the through-hole 820 in the width direction (X direction) may be smaller than the maximum length of the first structure M in the length direction (Y direction). Therefore, during the manufacture of the conductor-containing portion 804, the first structure M can be positioned in the through-hole 820 with a predetermined orientation. Specifically, the first structure M is positioned in the through-hole 820 with the length directions of the through-hole 820 and the first structure M being aligned or substantially aligned when viewed from above.

[0348] Alternatively, conductors 831 and 833 can be symmetrically arranged on both sides of conductor 832, forming a first structure M with a point-symmetric shape when viewed from above. Thus, even if the first structure M is relative to... Figure 35A The example shown is arranged vertically oppositely in the through hole 820, and it is also possible to manufacture a conductor containing part 804 with essentially the same structure.

[0349] exist Figure 35A In the top view, the first structure M and the through hole 820 have point-symmetric shapes, but they can also have asymmetrical shapes. For example, the shapes and sizes of conductors 831 and 833 can also be different from each other when viewed from above.

[0350] According to the circuit board of Modified Example 4, three conductors 831 to 833 can be arranged within a single through-hole 820, thus enabling further miniaturization of the circuit board. Furthermore, the cross-sectional area, connection method, and current flow direction of the conductors 831 to 833 can be designed according to their respective applications (current magnitude, etc.). Therefore, the degree of design freedom is increased.

[0351] Furthermore, in the circuit board of Modified Example 4, the width of conductors 831 and 833 in the X direction decreases as the conductor 832 moves further away from the center. With this structure, the magnetic field generated around each conductor 831-833 is less likely to be blocked by the conductors 831-833. Moreover, in Modified Example 4, the through-hole 820 has a structure in which three cylindrical holes corresponding to conductors 831-833 are arranged in a partially overlapping manner, allowing the magnetic field (magnetic flux) generated around each conductor 831-833 to easily pass through the magnetic material (substrate 810). Therefore, the inductance can be further improved.

[0352] Furthermore, in the circuit board of Modified Example 4, when viewed from above, conductors 831 and 833 are arranged close to conductor 832 at one end and the other end of conductor 832 in the Y direction, respectively. With this structure, magnetic coupling can be easily formed between two or three inductors composed of conductors 831 to 833.

[0353] (Variation Example 5)

[0354] Figure 36A This is a schematic top view of variation 5 of the conductor containing a portion. Figure 36B It is along Figure 36A A schematic cross-sectional view of the XXXVIB-XXXVIB line.

[0355] Figure 36A and Figure 36B The conductor containing portion 805 in the modified example 5 shown has a longer racetrack shape in the Y direction than the through hole 820 in the substrate 810. Figure 35A and Figure 35B The conductor in the modified example 4 shown contains a different part 804.

[0356] In the illustrated example, conductor 832 is disposed in the prism region Pa of the through-hole 820. Viewed from above, conductor 831 has a rectangular shape that is slightly smaller than the prism region Pa. Conductors 831 and 833 are respectively disposed in local cylindrical regions Pb of the through-hole 820. Furthermore, it is sufficient that conductors 831 and 833 are at least partially disposed in local cylindrical regions Pb.

[0357] According to Modification 5, similar to Modification 4, the magnetic field generated around each conductor 831 to 833 is not easily blocked by conductors 831 and 833.

[0358] Furthermore, according to this Modified Example 5, the opening of the through-hole 820 can be reduced compared to Modified Example 4. Therefore, the area of ​​the circuit board can be further reduced. In addition, the gap between the first structure M and the inner wall of the through-hole 820 can be reduced, thus allowing the substrate 4, which is a magnetic body, and the conductor 831 to be closer together. Moreover, since the conductors 831 to 833 are arranged close to each other within the through-hole 820 with a racetrack-shaped opening, stronger magnetic coupling can be formed between the two or three inductors composed of the conductors 831 to 833.

[0359] [Structure of the circuit board]

[0360] In the circuit board of this embodiment, the number of conductors in each conductor-containing portion, the connection method of the conductors, the direction of current flow, etc., can be arbitrarily combined. Such combinations are illustrated in Table 1.

[0361] [Table 1]

[0362]

[0363] In Table 1, "Number of Conductors" refers to the number of conductors disposed in a through-hole. "Electrical Isolation" refers to the number of conductors electrically isolated from each other in a through-hole. "Conductor Potential" refers to the potential of each conductor disposed in a through-hole, where the potentials differ between electrically isolated conductors. "Current Flow Direction" refers to the direction of current flow in each conductor disposed in a through-hole, indicated by arrows along the Z-direction. Furthermore, "Parallel" in Table 1 means that the current flows in the same direction (all parallel) in multiple electrically isolated conductors disposed in a through-hole. On the other hand, "Antiparallel" means that the current flows in opposite directions (antiparallel) in two electrically isolated conductors disposed in a through-hole. Additionally, "Direction of Magnetic Field" indicates the relationship between the directions of the magnetic fields generated around each conductor. "Same" means that the magnetic fields of each conductor are in the same direction, and "Opposite" means that the magnetic fields of each conductor are in opposite directions (reversed). Furthermore, in Table 1, when three conductors are arranged in a through hole, the conductor in the center of the arrangement direction (e.g., the Y direction) is designated as the "second conductor", and the conductors at both ends are designated as the "first conductor" and the "third conductor", respectively.

[0364] The conductor in this embodiment can also be considered as a plurality of parts obtained by dividing a cylindrical conductor (one conductor within an inductor unit cell) of the first embodiment into multiple parts in the Z direction. In this case, "number of conductors" refers to the number of parts into which a cylindrical conductor of the first embodiment is physically divided. Furthermore, "electrical isolation" refers to the number of parts into which a cylindrical conductor of the first embodiment is electrically divided.

[0365] Figures 30 to 33B The number of conductors in the illustrated conductors 800 to 804 is two, so they can be applied to the circuit boards of the structural examples (1) to (3). Figures 34A to 35B The number of conductors in the illustrated conductors 805 and 806 is three, so they can be applied to the circuit boards of the structural examples (4) to (11).

[0366] In the circuit board of this embodiment, one or more components (e.g., inductors) can be constructed using conductor-containing portions. Hereinafter, with respect to the circuit boards of the structural examples (2), (3), and (5) shown in Table 1, an example of the structure of the inductor using conductor-containing portions and an example of the circuit structure will be described.

[0367] (Structure Example (2))

[0368] <Structure of an Inductor>

[0369] The circuit board of structural example (2) includes, for example, multiple conductor-containing portions, multiple first electrodes disposed on the first surface side of the multiple conductor-containing portions, and multiple second electrodes disposed on the second surface side. Thus, two inductors are formed. In each conductor-containing portion, current flows in opposite directions (antiparallel) to each other in the Z direction in two conductors disposed in a through hole.

[0370] Figure 37A This is a top perspective view schematically representing the conductor containing part and the second electrode of structural example (2). Figure 37B This is a bottom perspective view schematically representing the conductor-containing part and the first electrode of structural example (2). For ease of understanding, the first electrode and the second electrode are represented by double-dotted lines.

[0371] exist Figure 37A and Figure 37B In the circuit board, multiple (in this case, three) conductor-containing portions 802a to 802c are arranged sequentially in the X direction. In each of the conductor-containing portions 802a to 802c, two conductors 831 and 832 are disposed within a through-hole 820. Conductor 832 is located on the +Y side of conductor 831.

[0372] In this example, each conductor containing portions 802a to 802c has a similar Figure 33A and Figure 33B The conductor shown contains the same structure as portion 802. Furthermore, the structure of these conductor portions is not limited to the example shown; for example, it could also be... Figures 30 to 33B The illustrated conductor contains any one of parts 800 to 804.

[0373] Multiple (four in this case) first electrodes 901ab, 901c, 902a, and 902bc are provided on the first surface 811 side of the conductor containing portions 802a to 802c. The first electrodes may also be disposed in the first wiring configuration 100. Figure 2 The first wiring layer 110 closest to the first face 811 in ) Figure 2 Within the conductor-containing portions 802a to 802c, a plurality of (in this case, four) second electrodes 911a, 911bc, 912ab, and 912c are provided on the second surface 812 side. The second electrodes may also be disposed within the second wiring configuration 200. Figure 2 The second wiring layer 210 closest to the second face 812 in ) Figure 2 )Inside.

[0374] In each conductor containing portions 802a to 802c, the end (first end) on the first surface 811 side of conductors 831 and 832 is electrically connected to any corresponding first electrode, and the end (second end) on the second surface 812 side is electrically connected to any corresponding second electrode. Each end of conductors 831 and 832 may also be electrically connected to the corresponding first or second electrode via a through conductor. Alternatively, other electrodes (corresponding to electrodes 31 and 32 in the aforementioned embodiments) may be sandwiched between the end of each conductor and the first or second electrode.

[0375] In this structural example, the conductors 831 of the conductor-containing portions 802a to 802c are connected in series to form an inductor 2a. Additionally, the conductors 832 of the conductor-containing portions 802a to 802c are connected in series to form an inductor 2b.

[0376] Inductor 2a includes conductors 831 with conductor-containing portions 802a to 802c, first electrodes 901ab and 901c, and second electrodes 911a and 911bc. The second end of conductor 831 in conductor-containing portion 802a is connected to the second electrode 911a and electrically connected to a predetermined terminal via the second electrode 911a. The first ends of conductors 831 in conductor-containing portions 802a and 802b are electrically connected to each other via the first electrode 901ab. The second ends of conductors 831 in conductor-containing portions 802b and 802c are electrically connected to each other via the second electrode 911bc. The first end of conductor 831 in conductor-containing portion 802c is connected to the first electrode 901c and electrically connected to a predetermined terminal via the first electrode 901c.

[0377] Inductor 2b includes conductors 832 with conductor-containing portions 802a to 802c, first electrodes 902a, 902bc, and second electrodes 912ab and 912c. The first end of conductor 832 in conductor-containing portion 802a is connected to the first electrode 902a and electrically connected to a predetermined terminal via the first electrode 902a. The second ends of conductors 832 in conductor-containing portions 802a and 802b are electrically connected to each other via the second electrode 912ab. The first ends of conductors 832 in conductor-containing portions 802b and 802c are electrically connected to each other via the first electrode 902bc. The second end of conductor 832 in conductor-containing portion 802c is connected to the second electrode 912c and electrically connected to a predetermined terminal via the second electrode 912c.

[0378] In this specification, the electrodes that electrically connect two conductors disposed in different through holes 820 are sometimes referred to as "connecting electrodes". In the illustrated example, electrodes 901ab and 902bc and electrodes 911bc and 912ab function as connecting electrodes.

[0379] In the circuit board of structural example (2), conductors 831 and 832 are electrically isolated. With this structure, conductors 831 and 832 can each form different components (in this case, inductors 2a and 2b). Therefore, more components can be incorporated while suppressing an increase in the area of ​​the circuit board. Furthermore, similar to the first embodiment, multiple (in this case, three) conductors containing portions 802a to 802c can be connected in series to form inductors (vertical inductors) 2a and 2b. That is, conductor portions 802a to 802c can function as individual inductor units. With this structure, the circuit board can be thinned.

[0380] Furthermore, in the circuit board of structural example (2), conductors 831 and 832 are connected to the corresponding electrodes in such a way that the current flows in opposite directions. Therefore, the directions of the magnetic fields generated by conductors 831 and 832 are opposite to each other (reversed).

[0381] Figure 37C This is a schematic enlarged top view illustrating the magnetic fields generated in conductors 831 and 832. Here, magnetic fields f1 and f2 are illustrated when current flows in conductor 831 in the +Z direction (from the first end to the second end) and in conductor 832 in the -Z direction (from the second end to the first end). Figure 37C As shown, in each conductor, the magnetic field f1 generated around conductor 831 and the magnetic field f2 generated around conductor 832 are in opposite directions (reversed) and cancel each other out. As a result, magnetic saturation is less likely to occur. Therefore, it is possible to suppress the decrease in inductor characteristics of each inductor composed of conductors 831 and 832 due to magnetic saturation.

[0382] If conductors 831 and 832 are arranged close together within the through-hole 820, the two magnetic fields f1 and f2 will move even closer to each other, thus canceling each other out more effectively. The amounts of current flowing in conductors 831 and 832 can also be approximately equal. Therefore, magnetic saturation can be suppressed more effectively.

[0383] <Circuit Structure>

[0384] Figure 38A This is a diagram illustrating an example of the circuit structure of a voltage regulation module (step-down DC-DC converter) using the circuit board of structure example (2). Figure 38B It is a simplification Figure 38A The circuit structure shown is a diagram. Figure 38A and Figure 38B The voltage regulation module shown is a DC-DC converter with multiple phases (multi-phase).

[0385] Figure 38A and Figure 38B The DC-DC converter shown includes the circuit board of the structural example (2) and two switching elements SW1 and SW2. The module has phase 1 when switching element SW1 is turned on and switching element SW2 is turned off, and phase 2 when switching element SW2 is turned on and switching element SW1 is turned off.

[0386] The inductors 2a and 2b, the input capacitor 5, and the output capacitor 6 constituting the circuit are built into the circuit board (component-integrated substrate). Capacitors 5 and 6 may also have the same structure as in the first embodiment described above. Terminals such as the control terminal CTL, the input terminal Vin, the output terminal Vout, and the ground terminal GND are formed, for example, in the first wiring structure (see reference). Figure 23A Additionally, the terminal pads for each terminal (SW1_CTL, SW2_CTL, SW1_Vout, SW2_Vout, SW_GND, etc.) of the switching elements SW1 and SW2 are formed, for example, in the second wiring configuration (see reference). Figure 23B ).

[0387] Inductor 2a is connected between the SW1_Vout terminal and the output terminal Vout of the switching element SW1. Inductor 2b is connected between the SW2_Vout terminal and the output terminal Vout of the switching element SW2. Inductors 2a and 2b, for example, have... Figure 37A and Figure 37B The illustrated structure. In each conductor-containing part 802a to 802c, the direction of current flowing in conductor 831 constituting inductor 2a and the direction of current flowing in conductor 832 constituting inductor 2b are opposite (parallel).

[0388] Preferably, the two conductors in each conductor portion are arranged close together to a degree that allows for magnetic coupling. (Refer to...) Figure 38C and Figure 38D Explain your reasoning. Figure 38C It means Figure 38A and Figure 38B The diagram shows phase 1 of the DC-DC converter. Figure 38D It is a schematic diagram showing the waveform of the ripple current generated in phase 1 of a DC-DC converter.

[0389] like Figure 38C As shown, in phase 1, when a ripple current rp1 is generated in the inductor 2a connected to the switched element SW1, a ripple current rp2 caused by the ripple current rp1 flows in the switched element SW2 through magnetic coupling. These ripple currents rp1 and rp2 are generated in a manner that reduces each other's current amplitude. As a result, as... Figure 38D As shown, by utilizing magnetic coupling, the current amplitudes of the ripple currents rp1 and rp2 generated in each phase can be suppressed compared to the case without magnetic coupling.

[0390] In typical DC-DC converters, increasing the inductance value is necessary to suppress ripple current below a predetermined value (e.g., approximately 30% of the load current). Conversely, in... Figure 38A In the DC-DC converter shown, such as Figure 38D As shown, ripple current can be suppressed, thus allowing for a smaller inductance value. As a result, inductors 2a and 2b can be further miniaturized.

[0391] (Structure Example (3))

[0392] <Structure of an Inductor>

[0393] The circuit board of structural example (3) includes, for example, multiple conductor-containing portions, multiple first electrodes, and multiple second electrodes. Thus, two inductors are formed. In each conductor-containing portion, the current flows in the same direction in the Z direction in the two conductors arranged in a through hole.

[0394] Figure 39A This is a top perspective view schematically representing the conductor containing part and the second electrode of structural example (3). Figure 39B This is a bottom perspective view schematically showing the conductor-containing part and the first electrode of structural example (3). For ease of understanding, the first electrode and the second electrode are indicated by double-dotted lines. Hereinafter, the differences from structural example (2) will be mainly explained, and repeated explanations will be omitted as appropriate.

[0395] In the illustrated example, multiple (four in this case) first electrodes 901a, 901bc, 902a, and 902bc are provided on the first surface 811 side of the conductor containing portions 802a to 802c. Multiple (four in this case) second electrodes 911ab, 911c, 912ab, and 912c are provided on the second surface 812 side of the conductor containing portions 802a to 802c.

[0396] In this structural example, the conductors 831 of the conductor-containing portions 802a to 802c are connected in series to form an inductor 2c. Additionally, the conductors 832 of the conductor-containing portions 802a to 802c are connected in series to form an inductor 2d.

[0397] Inductor 2c includes conductors 831 in conductor-containing portions 802a to 802c, first electrodes 901a, 901bc, and second electrodes 911ab and 911c. The first end of conductor 831 in conductor-containing portion 802a is electrically connected to a predetermined terminal via the first electrode 901a. The second ends of conductors 831 in conductor-containing portions 802a and 802b are electrically connected to each other via the second electrode 911ab. The first ends of conductors 831 in conductor-containing portions 802b and 802c are electrically connected to each other via the first electrode 901bc. The second end of conductor 831 in conductor-containing portion 802c is electrically connected to a predetermined terminal via the second electrode 911c. Inductor 2d has the same structure as inductor 2b in structural example (2).

[0398] In the circuit board of structural example (3), conductors 831 and 832 are electrically isolated, so conductors 831 and 832 can respectively form different components (in this case, inductors 2c and 2d).

[0399] Furthermore, in the circuit board of structural example (3), conductors 831 and 832 are connected to the corresponding electrodes in a manner where the current flows in parallel. According to this structure, the magnetic fields generated by conductors 831 and 832 are in the same direction, and can reinforce each other. Therefore, the characteristics of the inductor constructed from conductors 831 and 832 can be improved.

[0400] <Circuit Structure>

[0401] Figure 40 This is a diagram illustrating an example of the circuit structure of a voltage regulation module (step-down DC-DC converter) using the circuit board of structure example (3). Figure 40 The DC-DC converter shown is a multiphase DC-DC converter that includes two switching elements SW1 and SW2.

[0402] In this example, two sets of inductors 2c and 2d (hereinafter referred to as "inductor block BL1" and "inductor block BL2") are built into the circuit board. Inductor 2c of inductor block BL1 is connected between the SW1_Vout terminal and the output terminal Vout of the switching element SW1. Inductor 2c of inductor block BL2 is connected between the SW2_Vout terminal and the output terminal Vout of the switching element SW2. Inductors 2d of inductor blocks BL1 and BL2 are connected in series with each other between the ground terminal GND.

[0403] Inductors 2c and 2d of each inductor block BL1 and BL2 have Figure 39A and Figure 3B The illustrated structure. In each conductor containing portions 802a to 802c, the current flows in the same direction (parallel) in conductor 831 constituting inductor 2c and conductor 832 constituting inductor 2d.

[0404] according to Figure 40 The DC-DC converter shown has a structure called a Trans-Inductor-Voltage Regulator (TLVR) built into the circuit board, which improves the load transient response characteristics. Furthermore, if the two conductors 831 and 832 of each conductor containing portions 802a to 802c are arranged close to each other, the conductors 831 and 832 are more magnetically coupled, thus further improving the load transient response characteristics.

[0405] To explain the above effects in more detail: In existing multiphase power supplies, the increase or decrease of the inductor's load current is detected based on the change in the FB voltage at the FB terminal. The control IC is configured to correct for excess or insufficient current caused by the increase or decrease in current by controlling the duty cycle (the ratio of on time to off time) of the signal applied to the control terminals CTL1 and CTL. That is, feedback control is performed using the control IC.

[0406] In contrast, Figure 40 In the circuit shown, during phase 1 when a switching element (e.g., switching element SW1) is turned on, the increase or decrease in load current of inductor 2c (inductor 2c of inductor block BL1) connected to switching element SW1 is detected by inductor 2d. Then, via magnetic coupling, current of the increased or decreased amount is supplied from inductor 2c of inductor block BL2. This allows for correction of excessive or insufficient current. Thus, by linking the inductors 2c of inductor blocks BL1 and BL2 together, high-speed load transient response can be achieved. According to this circuit structure, excess or insufficient current caused by changes in current can be corrected (by applying feedback) before feedback control by a control IC, thus enabling faster operation.

[0407] (Structure Example (5))

[0408] <Structure of an Inductor>

[0409] The circuit board of structural example (5) includes, for example, multiple conductor-containing portions, multiple first electrodes, and multiple second electrodes. Thus, two inductors are formed. In each conductor-containing portion, three conductors are arranged in a through hole, configured such that current flows in opposite directions (anti-parallel) in the Z direction in two of the conductors and the remaining conductor.

[0410] Figure 41A This is a top perspective view schematically representing the conductor containing part and the second electrode of structural example (5). Figure 41B This is a bottom perspective view schematically showing the conductor-containing part and the first electrode of structural example (5). For ease of understanding, the first electrode and the second electrode are indicated by double-dotted lines. Hereinafter, the differences from structural example (2) will be mainly explained, and repeated explanations will be omitted as appropriate.

[0411] exist Figure 41A and Figure 41B In the circuit board, multiple (in this case, three) conductor-containing portions 805a to 805c are arranged sequentially in the X direction. In each of the conductor-containing portions 802a to 802c, in the Y direction, conductor 832 is located between conductors 831 and 833.

[0412] In this example, each conductor containing portions 805a to 805c has a similar Figure 36A and Figure 36B The conductor shown contains the same structure as portion 805. Furthermore, the structure of these conductor portions is not limited to the example shown; for example, it could also be... Figure 35A and Figure 35B The conductor shown contains part 804.

[0413] In this example, similar to structural example (2), first electrodes 901ab, 901c, 902a, 902bc and second electrodes 911a, 911bc, 912ab, 912c are provided on the circuit board. Conductors 831 and 832 in each conductor-containing portion are connected to the same electrodes to have the same potential. Conductor 833 in each conductor-containing portion is connected to electrodes different from the other conductors 831 and 832 to have different potentials.

[0414] In this structural example, conductors 831 and 832 of conductor-containing portions 802a to 802c are connected in series to form an inductor 2e. Additionally, conductors 833 of conductor-containing portions 802a to 802c are connected in series to form an inductor 2f.

[0415] In inductor 2e, the first electrodes 901ab, 901c and the second electrodes 911a, 911bc electrically connect the conductors 831, 832 of each conductor-containing portion, and are arranged in series, similar to the first inductor 2a of structural example (2), in a manner that the conductor portions consisting of conductors 831, 832 of conductor-containing portions 802a to 802c are connected in series. In inductor 2f, similar to the inductor 2b of structural example (2), the first electrodes 902a, 902bc and the second electrodes 912ab, 912c are arranged in a manner that the conductors 833 of conductor-containing portions 802a to 802c are connected in series.

[0416] In the circuit board of structural example (5), conductors 831, 833, and 832 are arranged close together within the through-hole 820 and connected to the corresponding electrodes in a manner where the current flows in opposite directions. Therefore, the directions of the magnetic fields generated by conductors 831 and 833 are opposite to the direction of the magnetic field generated by conductor 832. Consequently, magnetic saturation is less likely to occur, thus suppressing the degradation of inductor characteristics caused by magnetic saturation.

[0417] (Other structural examples)

[0418] •Structure Example (1)

[0419] In structural examples (2) and (3), conductors 831 and 832 are electrically isolated, but they can also be electrically connected. For example, the first ends of conductors 831 and 832 can be electrically connected to each other using the first electrode, and the second ends can be electrically connected to each other using the second electrode (structural example (1)). In structural example (1), the potentials of these conductors are equal and the current flows in the same direction.

[0420] •Structure Example (4)

[0421] In structural example (5), each conductor containing conductors 831 to 833 is electrically isolated as two, but it is also possible that these three conductors are not electrically isolated. For example, it is also possible that the first ends of the three conductors are electrically connected to each other using the first electrode, and the second ends are electrically connected to each other using the second electrode (structural example (4)). In structural example (4), the potentials of these conductors are equal and the current flows in the same direction.

[0422] •Structure Example (6)

[0423] In structural example (5), conductors 831 to 833, each containing a part, are electrically isolated into two, so that the directions of the two currents (i.e., the direction of the current flowing in conductors 831 and 832 and the direction of the current flowing in conductor 833) are opposite and parallel, but the directions of these currents can also be parallel (structural example (6)).

[0424] •Structural examples (7) and (8)

[0425] In structural example (5), conductors 831 and 832 in each conductor containing conductors 831 to 833 have the same potential V1, and conductor 833 has a different potential V2. However, it is also possible that conductors 831 and 833 have the same potential V1, while the central conductor 832 has a different potential V2. In this case, the direction of current flow in conductors 831 and 833 can be either parallel to or opposite to the direction of current flow in conductor 832 (structural example (7)) or parallel to it (structural example (8)).

[0426] •Structural examples (9) to (11)

[0427] Alternatively, conductors 831 to 833, each containing a portion of the conductor, can be electrically isolated from each other (i.e., electrically isolated as three). In this case, the current flow directions of conductors 831 to 833 can all be the same (parallel) (Structure Example (9)). Alternatively, the current can be configured such that the current flows in the same direction in conductors 831 and 832, and the current flows in the opposite direction (antiparallel) to the current flow in conductor 833 (Structure Example (10)). Furthermore, the current can be configured such that the current flows in the same direction in conductors 831 and 833 at both ends, and the current flows in the opposite direction (antiparallel) to the current flow in conductor 832 in the middle (Structure Example (11)). In Structure Examples (10) and (11), the magnetic fields generated by two of the three electrically independent conductors 831 to 833 are in the same direction, and the magnetic field generated by the other conductor is in the opposite direction (mixed same and opposite).

[0428] Furthermore, the structure of the circuit board in this embodiment is not limited to the structure described above. In Table 1, the number of conductors is 2 or 3, but it can also be 4 or more. Additionally, in Figures 37A to 41B The example shown includes three conductor-containing portions, but the circuit board of this embodiment only needs to include at least one conductor-containing portion, and the number of conductor-containing portions is not particularly limited. Moreover, in the circuit board of this embodiment, conductor-containing portions with different structures (e.g., different numbers and shapes of conductors) may be mixed together.

[0429] Furthermore, the position, shape, cross-sectional area of ​​conductors 831-833, and the position and shape of electrodes are not limited to the examples shown in the illustrations, and can be appropriately set according to the design of the circuit board. Figures 30-41B In the diagram, conductors 831 to 833 are all square prisms, but they can also be other polygonal prism shapes. Alternatively, the conductor can also be a prism shape other than a polygonal prism, such as a cylinder, semi-cylindrical, elliptical prism, or semi-elliptical prism. For example, in... Figures 30 to 33B In the example shown, conductors 831 and 832 have the same cross-sectional area, but their cross-sectional areas can also be different. Figures 35A to 36B In the example shown, conductors 831 and 833 have the same cross-sectional area and shape, but they can also be different from each other. Furthermore, conductors 831 and 832 are arranged symmetrically with one conductor 832 between them when viewed from above, but they can also be asymmetrical.

[0430] The structure of the DC-DC converter using the circuit board of this embodiment is not limited to... Figure 38A , Figure 40 The illustrated structure. In Figure 38A In this example, the circuit board of structure (2) is used, but it can also be replaced by other structures in which the current flows in parallel to the current in the two conductors within the through-hole. Figure 40 In this example, the circuit board of structure example (3) is used, but it can also be replaced by other structures in which the current flows of the two conductors in the through-hole are in opposite parallel directions. The circuit structure, the number of switching elements, etc. are not limited to the examples shown in the figure. Moreover, the circuit boards of structures examples (1) and (4) can also be used to construct the circuit. Figure 6 The DC-DC converter shown.

[0431] Furthermore, the above description uses the conductor-containing part that constitutes an inductor as an example, but the conductor-containing part can also constitute a component other than an inductor.

[0432] [Manufacturing method for conductor containing part]

[0433] This invention describes a method for manufacturing the conductor containing the portion according to the present embodiment. Here, the manufacturing process is described using... Figure 34A and Figure 34B The following explanation will be based on the case where the conductor containing part 803 also has a first structure M with a conductor 831 having a rectangular cross-section and a conductor 832 having a trapezoidal cross-section.

[0434] (The creation of the first construct M)

[0435] Figures 42A to 4 2E is a schematic three-dimensional diagram illustrating the manufacturing method of the first structural body M. Firstly, as... Figure 42A As shown, a first metal foil (e.g., copper foil) 8310, which will become conductor 831, and a second metal foil (e.g., copper foil) 8320, which will become conductor 832, are stacked with an adhesive layer (e.g., adhesive sheet) 8400, which will become insulating layer 840, to form a laminate 8000. Then, as... Figure 42BAs shown, the first metal foil 8310 and / or the second metal foil 8320 are processed (etched). Here, multiple grooves 8311 extending in one direction (Z direction in this figure) are formed on the first metal foil 8310, separating the first metal foil 8310 into multiple portions 8312. Each portion 8312 is a quadrangular prism with a trapezoidal cross-section. Although not shown, an insulating film that becomes an insulating layer 850 may also be formed on the upper and lower surfaces of the processed laminate 8000. Then, as shown in FIG43C, the laminate 8000 is cut in a direction intersecting (orthogonal in this case) with the upper surface of the laminate 8000. In this way, multiple first structures M are obtained.

[0436] (Manufacturing of the conductor containing the part)

[0437] Figure 43A This is a schematic three-dimensional diagram illustrating the manufacturing process of a conductor containing a portion. For example... Figure 43A As shown, a substrate (e.g., a magnetic material) 810 with through holes 820 is prepared. The width of the substrate 810 in the X direction is, for example, 4.0 mm, and the width in the Y direction is, for example, 3.0 mm. The through holes 820 are obtained, for example, by drilling to form cylindrical through holes (first holes) of radius d1 and cylindrical through holes (second holes) of radius d2 in a manner that partially overlaps each other. In this example, a plurality of (here, three) through holes 820 are arranged on the substrate 810 at intervals (e.g., 0.75 mm) in the X direction.

[0438] Next, the first structure M manufactured by the above method is inserted into each through hole 820 of the substrate 810. Then, the first structure M is sealed. Here, a resin member forming an insulating portion 860 is formed in the gap between the first structure M and the inner wall of the through hole 820, and sealing insulating layers covering the lower and upper surfaces of each conductor are formed respectively. Next, a through hole is formed in the sealing insulating layer, and a conductive path is formed within the through hole.

[0439] Figure 43B This is a three-dimensional diagram representing the first structure M that forms a conductive path. Figure 43B The diagram of the sealing insulation layer is omitted.

[0440] like Figure 43B As shown, multiple conductive paths 830 are formed at intervals on the first and second end faces of conductors 831 and 832. The first and second end faces of conductors 831 and 832 are located on the first surface 811 side and the second surface 812 side of the substrate 810, respectively (see reference). Figure 34B The thickness h1 of conductors 831 and 832 in the Z direction is determined according to the thickness of the substrate 810, for example, 0.8 mm. The width t1 of the insulating layer 840 is determined by... Figure 42AThe thickness of the adhesive layer 8400 shown is adjusted, for example, to 0.015 mm.

[0441] Subsequently, electrodes (equivalent to electrodes 31 and 32 in the aforementioned embodiments) may be formed on the conductor as needed. Electrodes may also be provided for each conductor. This is how the conductor containing portion is manufactured.

[0442] Alternatively, a substrate 810 having three conductor-containing portions can be disposed on the core substrate 10 (see reference). Figure 3A The opening of the core substrate can be used as an example. Alternatively, the substrate 810 can be partially cut for each conductor and then disposed at the opening of the core substrate. This results in a component-embedded substrate. Subsequently, as in the aforementioned embodiment, a circuit board can be manufactured by forming wiring structures on both sides of the component-embedded substrate.

[0443] (Design Methodology)

[0444] Figure 44A and Figure 44B These are schematic top views of the first structure M, illustrating an example of the design method for the first structure M.

[0445] The lengths of conductors 831 and 832 in the X and Y directions are designed to facilitate the formation of magnetic fields in each conductor 831 and 832 while also ensuring a large cross-sectional area. See below for reference. Figure 44A This illustrates the relationship between the lengths of conductors 831 and 832 in the X and Y directions and the opening shape of the through hole 820.

[0446] exist Figure 44A In the example shown, the through hole 820 has a configuration in which a cylindrical first hole of radius d1 and a cylindrical second hole of radius d2 are arranged in a partially overlapping manner. A first region Pc1 defined by the inner wall of the first hole and a second region Pc2 defined by the inner wall of the second hole are interconnected. In top view, the radii d1, d2 and the distance d3 between the center of the first hole and the center of the second hole are set, for example, in a manner that satisfies the following relationship.

[0447] (d3) 2 ≤(d1) 2 +(d2) 2

[0448] Therefore, when viewed from above, at the intersection of the inner walls of the first and second holes, the angle α formed by the tangents to the inner walls of the first and second holes is not acute. This reduces magnetic reluctance and improves the magnetic coupling of conductors 831 and 832. In this example, radius d2 is larger than radius d1 (d2>d1). Radius d1 is, for example, 0.5 mm, and radius d2 is, for example, 0.65 mm.

[0449] When viewed from above, conductor 832 is a polygon smaller than the polygon inscribed in the second region Pc2, which is a partial circle. The polygon is, for example, an n-sided polygon (n is 4 or more). Thus, conductor 832 can be positioned inside the second region Pc2 of the through-hole 820.

[0450] exist Figure 44A In the diagram, when viewed from above, conductor 832 is, for example, rectangular. The length u2 of conductor 832 in the Y direction passes through the second metal foil 8320 (…). Figure 42A The thickness of the conductor 832 is adjusted by etching, for example, to 0.8 mm. The width w3 in the X direction of the conductor 832 is adjusted by etching, for example, to 1.0 mm.

[0451] When viewed from above, conductor 831 is a polygon with two vertices on the side closest to conductor 832 (the side closest to the first region Pc1). The polygon is, for example, an n-sided polygon (n is 4 or more). When viewed from above, the vertex of the polygon of conductor 831 that is farthest from conductor 832 can also be located slightly inside the arc of the first region Pc1, which is a local circle. Therefore, it is possible to further increase the cross-sectional area of ​​conductor 831 while placing conductor 832 inside the second region Pc2.

[0452] exist Figure 44A In the top view, conductor 831 is a trapezoid with a lower base on the side of conductor 832. The two vertices on either side of the upper base of the trapezoid are located slightly inside the points on the arc of the first region Pc1, which is a local circle. The length u1 of conductor 831 in the Y direction passes through the first metal foil 8310 ( Figure 42A The thickness of the conductor 831 can be adjusted by etching, for example, by setting the thickness to 0.8 mm. The widths w1 and w2 in the X direction of the conductor 831 can be adjusted by etching. Width w1 (length of the lower base of the trapezoid) is, for example, 0.7 mm. Width w2 (length of the upper base of the trapezoid) is, for example, 0.5 mm. The base angles at both ends of the lower base of the trapezoid can be adjusted by the etching method and etching conditions to achieve the desired angle (acute angle). In this example, lengths u1 and u2 are equal, but they can also be different.

[0453] Next, refer to Figure 44BThe dimensions and arrangement of the pass conductors 830 are described below. Here, one end of each pass conductor 830 is connected to the end face (first end face or second end face) of conductors 831 and 832. The pass conductor 830 is cylindrical with a radius of d4 and extends in the Z direction away from the end face of conductors 831 and 832. Adjacent pass conductors 830 are arranged at least d5 apart from each other. As an example, the position and number of pass conductors 830 can also be determined by arranging concentric circles formed by a circle of radius d4 and an imaginary circle 830i of radius d4 + d5 on the end face of conductors 831 and 832 when viewed from above. This allows for a predetermined interval (distance d5) to be ensured on the first end face of conductors 831 and 832, and enables a more compact arrangement of multiple pass conductors 830. The radius d4 of the cylindrical pass conductor 830 is, for example, 0.0575 mm. The distance d5 is, for example, 0.05 mm.

[0454] In the above method, a first structure M comprising a plurality of conductors 831, 832 separated by an insulating layer 840 is disposed in a through hole 820 of the substrate 810. By disposing the separately manufactured first structure M in the through hole of the substrate 810, the plurality of conductors 831, 832 can be more easily disposed in the through hole 820 at predetermined distances. In addition, the distance between conductors 831, 832 and the positional relationship between conductors 831, 832 are easier to control.

[0455] In the above method, the through-hole 820 and the first structure M can also have a planar shape that is longer in one direction or an asymmetrical shape. Therefore, it is easier to arrange multiple conductors 831, 832 in a predetermined orientation within the through-hole 820. Thus, no alignment construction or process is required, which is advantageous.

[0456] Furthermore, the method for manufacturing the circuit board in this embodiment is not limited to the method described above. For example, multiple columnar conductors (e.g., cylindrical Cu leads) with their peripheral surfaces covered by an insulating layer may be prepared, and these conductors may be disposed in a through-hole of the substrate. Subsequently, the area in the through-hole where the multiple conductors are not disposed may be filled with resin or the like.

[0457] Implementation Method 4

[0458] The fourth embodiment is a voltage regulation module including an inductor-embedded circuit board. For use... Figure 1 and Figure 2 The following explanation will be based on the example of circuit board 1 being a circuit board for an inductor.

[0459] Figure 45 This is a schematic cross-sectional view illustrating an example of the voltage regulation module 400 according to the fourth embodiment. The voltage regulation module 400, for example, has the features described above. Figure 6The circuit structure of the described buck converter.

[0460] The voltage regulation module 400 is disposed, for example, on the main surface 500s of the system substrate (motherboard) 500. Alternatively, a power management IC (PMIC) may also be disposed on the main surface 500s. Although not shown, the computing processing device may also be disposed on the main surface on the opposite side of the system substrate 500.

[0461] The voltage regulation module 400 includes a circuit board 1 with a built-in inductor and a switching element SW.

[0462] The circuit board 1 is the same as the circuit board 1 in the aforementioned embodiment. An inductor 2 and a two-terminal capacitor (input capacitor, output capacitor, etc.) are built into the circuit board 1. The circuit board 1 is arranged such that its first main surface s1, which is provided with terminals such as input terminal Vin and output terminal Vout, is opposite to the main surface 500s of the system board 500.

[0463] The switching element SW is disposed on the second main surface s2 of the circuit board 1. The switching element SW includes MOSFETs on the high-side and low-side and multiple terminals (see reference). Figure 6 Each terminal of the switching element SW is connected to the corresponding pad on the second main surface s2 of the circuit board 1.

[0464] According to the voltage regulation module 400 of this embodiment, components such as inductors 2 and two-terminal capacitors are arranged side-by-side within the circuit board 1. Furthermore, the inductors 2 are divided into multiple units and integrated within the circuit board 1. Therefore, a thinner form factor for the voltage regulation module 400 can be achieved.

[0465] Furthermore, in the voltage regulation module 400 of this embodiment, the output terminal p1 of the inductor 2 is located on the first main surface s1 side. Therefore, the path between the output terminal p1 of the inductor 2 and the output terminal Vout can be shortened. Additionally, the input terminal p2 of the inductor 2 is located on the second main surface s2 side, thus shortening the path between the input terminal p2 of the inductor 2 and the switching output terminal SW_Vout of the switching element SW. Therefore, the resistance from the switching output terminal SW_Vout of the switching element SW to the output terminal Vout can be further reduced. Therefore, a more efficient voltage regulation module 400 can be provided.

[0466] The structure and configuration of the voltage regulation module in this embodiment are not limited to... Figure 45The example shown. Any of the circuit boards illustrated in embodiments 1 to 3 can be used as the circuit board. The voltage regulation module of this embodiment only needs to be configured such that an inductor built into the circuit board of this embodiment is connected between the output terminal of the switching element and the output terminal of the module. Furthermore, in this embodiment, the inductor-built circuit board is applied to a buck converter, but it can also be applied to other regulators such as boost or buck-boost converters.

[0467] This disclosure is not limited to the embodiments described above, and design changes can be made without departing from the spirit of this disclosure. Furthermore, by appropriately combining the structures of any of the illustrated embodiments (including variations), the respective effects can be achieved.

[0468] The inductor-embedded circuit board disclosed herein can also be described as follows.

[0469] The inductor-embedded circuit board of the first embodiment includes: a substrate having a first surface and a second surface located on the side opposite to the first surface in the thickness direction; a first wiring layer disposed on the first surface of the substrate with a first insulating portion; a second wiring layer disposed on the second surface of the substrate with a second insulating portion; and an inductor located inside the substrate, the inductor including: a first conductor, a second conductor, and a third conductor disposed within the substrate at a distance from each other when viewed from above along the thickness direction and extending respectively in the thickness direction; a first magnetic body located around the first conductor in a manner surrounding the peripheral surface of the first conductor; a second magnetic body located around the second conductor in a manner surrounding the peripheral surface of the second conductor; and a third magnetic body located around the third conductor in a manner surrounding the peripheral surface of the third conductor. The first conductor, the second conductor, and the third conductor are located around the third conductor. Each of the first conductor, the second conductor, and the third conductor has a first end on the first surface and a second end on the second surface within the substrate. The first wiring layer has a first connecting electrode that electrically connects the first end of the first conductor and the first end of the second conductor to each other. The second wiring layer has a second connecting electrode that electrically connects the second end of the second conductor and the second end of the third conductor to each other. The first end of each of the first conductor and the second conductor is electrically connected to the first connecting electrode via a through conductor disposed within the first insulating portion. The second end of each of the second conductor and the third conductor is electrically connected to the second connecting electrode via a through conductor disposed within the second insulating portion.

[0470] The second type of inductor built-in circuit board is based on the first type of inductor built-in circuit board, wherein the first conductor, the second conductor, and the third conductor are connected in series, one of the input terminal and the output terminal of the inductor is connected to the wiring in the first wiring layer via a through conductor disposed in the first insulating portion, and the other of the input terminal and the output terminal of the inductor is connected to the wiring in the second wiring layer via a through conductor disposed in the second insulating portion.

[0471] The third type of inductor-embedded circuit board is based on the first or second type of inductor-embedded circuit board, wherein the inductor has a first electrode within the substrate, the first electrode being located on the first surface side of the first end of the first conductor and electrically connected to the first conductor, and in a top view viewed along the thickness direction, the first electrode is configured to overlap at least partially with the entire first conductor and the first magnetic body.

[0472] The fourth type of inductor built-in circuit board is based on the third type of inductor built-in circuit board, wherein the first electrode of the first conductor is electrically connected to the first connecting electrode via a plurality of through conductors disposed in the first insulating portion, and when viewed from above along the thickness direction, at least one of the plurality of through conductors is located outside the first conductor.

[0473] The fifth type of inductor-embedded circuit board, based on any one of the first to fourth types of inductor-embedded circuit boards, has at least one two-terminal capacitor located inside the substrate, and the at least one two-terminal capacitor and the inductor are arranged side by side in a direction intersecting the thickness direction.

[0474] The inductor-embedded circuit board of the sixth embodiment is based on the inductor-embedded circuit board of the fifth embodiment. The at least one two-terminal capacitor includes: a dielectric; a lower electrode located on the first surface side of the dielectric; and an upper electrode located on the second surface side of the dielectric. The lower electrode is electrically connected to wiring in the first wiring layer via a conductor provided in the first insulating portion, and the upper electrode is electrically connected to wiring in the second wiring layer via a conductor provided in the second insulating portion.

[0475] The inductor-embedded circuit board of the seventh embodiment is based on the inductor-embedded circuit board of any one of the first to sixth embodiments, wherein the first magnetic body, the second magnetic body, and the third magnetic body are integrally formed.

[0476] The inductor-embedded circuit board of the eighth embodiment is based on the inductor-embedded circuit board of the seventh embodiment. The inductor has the following internal components in the substrate: a first electrode electrically connected to a first end of a first conductor; a second electrode electrically connected to a first end of a second conductor; a third electrode electrically connected to a second end of the second conductor; and a fourth electrode electrically connected to a second end of the third conductor. The first electrode and the second electrode are integrally formed, and the third electrode and the fourth electrode are integrally formed.

[0477] The voltage regulation module of the ninth method includes: an inductor-embedded circuit board of any one of the methods 1 to 8; an input terminal and an output terminal; and a switching element connected between the input terminal and the inductor.

[0478] The voltage regulation module of the 10th embodiment is based on the voltage regulation module of the 9th embodiment. The inductor built-in circuit board has: a first main surface located on the first surface side of the substrate; and a second main surface located on the second surface side of the substrate for configuring the input terminal and the output terminal, and the switching element is configured on the first main surface.

[0479] The conductor-embedded circuit board disclosed herein can also be described as follows.

[0480] The conductor-embedded circuit board of the first embodiment includes: a substrate having a first surface, a second surface located on the side opposite to the first surface in the thickness direction, and a through hole extending in the thickness direction; a first wiring layer disposed on the first surface of the substrate; a second wiring layer disposed on the second surface of the substrate; and a first conductor and a second conductor disposed within the through hole and extending in the thickness direction, wherein the conductor-embedded circuit board further includes an insulating layer in the through hole, which, when viewed from above along the thickness direction, is located between the first conductor and the second conductor and isolates the first conductor from the second conductor.

[0481] The second type of conductor-embedded circuit board is based on the first type of conductor-embedded circuit board, wherein the first conductor and the second conductor are electrically isolated.

[0482] The third type of conductor-embedded circuit board is based on the second type of conductor-embedded circuit board, wherein the conductor-embedded circuit board is configured such that current flows in opposite directions in the thickness direction of the first conductor and the second conductor.

[0483] The fourth type of conductor-embedded circuit board is based on the second type of conductor-embedded circuit board, wherein the conductor-embedded circuit board is configured such that current flows in the same direction in the thickness direction in the first conductor and the second conductor.

[0484] The fifth type of conductor-embedded circuit board is based on the first type of conductor-embedded circuit board, wherein the first conductor is electrically connected to the second conductor.

[0485] The sixth type of conductor-embedded circuit board, based on any of the first to fifth types of conductor-embedded circuit boards, has the first conductor and the second conductor facing each other in the first direction when viewed from above along the thickness direction, separated by the insulating layer, and the width of the first conductor in the second direction orthogonal to the first direction decreases as it moves away from the second conductor along the first direction.

[0486] The conductor-embedded circuit board of the seventh embodiment, based on the conductor-embedded circuit board of any of the first to sixth embodiments, has a through-hole that is elongated in one direction when viewed from above along the thickness direction.

[0487] The conductor-embedded circuit board of the eighth embodiment is based on the conductor-embedded circuit board of the seventh embodiment. The first conductor, the second conductor, and the insulating layer constitute a first structure. When viewed from above along the thickness direction, the first structure has a longer shape in one direction. When viewed from above along the thickness direction, the first structure is arranged inside the through hole in such a way that the length direction of the first structure is consistent with or substantially consistent with the length direction of the through hole.

[0488] The conductor-embedded circuit board of the ninth embodiment, based on the conductor-embedded circuit board of any one of the embodiments 1 to 4, further includes a first inductor and a second inductor that can operate independently between the first wiring layer and the second wiring layer, wherein the first inductor includes the first conductor and the second inductor includes the second conductor.

[0489] The conductor-embedded circuit board of the 10th embodiment is based on the conductor-embedded circuit board of any one of the 1st to 9th embodiments, wherein the first conductor and the second conductor each have: a first end located on the first surface side and electrically connected to an electrode in the first wiring layer; and a second end located on the second surface side and electrically connected to an electrode in the second wiring layer.

[0490] The conductor-embedded circuit board of the 11th embodiment is based on the conductor-embedded circuit board of any of the 1st to 10th embodiments, and the conductor-embedded circuit board further includes a third conductor disposed within the through hole and extending in the thickness direction. When viewed from above along the thickness direction, the third conductor is disposed in the through hole at a distance from the first conductor and the second conductor.

[0491] The conductor-embedded circuit board of the 12th embodiment, based on the conductor-embedded circuit board of the 11th embodiment, wherein, when viewed from above along the thickness direction, in the first direction, the second conductor is located between the first conductor and the third conductor, and the insulating layer comprises a first insulating layer located between the first conductor and the second conductor and a second insulating layer located between the second conductor and the third conductor.

[0492] Based on the conductor-embedded circuit board of the 12th embodiment, the conductor-embedded circuit board of the 13th embodiment, when viewed from above along the thickness direction, has a width in the second direction of the first conductor that is orthogonal to the first direction decreasing as it moves away from the second conductor along the first direction, and a width in the second direction of the third conductor decreasing as it moves away from the second conductor along the first direction.

[0493] The conductor-embedded circuit board of the 14th embodiment is based on the conductor-embedded circuit board of any of the 11th to 13th embodiments, wherein the first conductor and the second conductor are electrically connected, and the third conductor is electrically isolated from the first conductor and the second conductor.

[0494] The conductor-embedded circuit board of the 15th embodiment is based on the conductor-embedded circuit board of the 14th embodiment, wherein the conductor-embedded circuit board is configured such that current flows in the same direction in the thickness direction in the first conductor and the second conductor, and current flows in the third conductor in the opposite direction to the first conductor and the second conductor.

[0495] The conductor-embedded circuit board of the 16th embodiment is based on the conductor-embedded circuit board of the 14th embodiment, wherein the conductor-embedded circuit board is configured such that current flows in the same direction in the thickness direction in the first conductor, the second conductor, and the third conductor.

[0496] The conductor-embedded circuit board of the 17th embodiment is based on the conductor-embedded circuit board of any of the 11th to 13th embodiments, wherein the first conductor, the second conductor, and the third conductor are electrically isolated from each other.

[0497] The conductor-embedded circuit board of the 18th embodiment is based on the conductor-embedded circuit board of the 17th embodiment, wherein the conductor-embedded circuit board is configured such that current flows in the same direction in the thickness direction in the first conductor and the second conductor, and current flows in the third conductor in the opposite direction to the first conductor and the second conductor.

[0498] The conductor-embedded circuit board of the 19th embodiment is based on the conductor-embedded circuit board of the 17th embodiment, wherein the conductor-embedded circuit board is configured such that current flows in the same direction in the thickness direction in the first conductor, the second conductor, and the third conductor.

[0499] The conductor-embedded circuit board of the 20th embodiment is based on the conductor-embedded circuit board of any one of the 11th to 13th embodiments, wherein the first conductor, the second conductor, and the third conductor are electrically connected.

[0500] The conductor-embedded circuit board of the 21st embodiment, based on the conductor-embedded circuit board of the 9th embodiment, includes a plurality of conductor-containing portions. Each conductor-containing portion has the substrate, the first conductor, the second conductor, and the insulating layer. The first conductors of the plurality of conductor-containing portions are connected in series to form the first inductor, and the second conductors of the plurality of conductor-containing portions are connected in series to form the second inductor.

[0501] Industrial availability

[0502] The conductor-embedded circuit board of the present invention can be miniaturized, and therefore can be appropriately applied to various devices such as voltage regulation modules.

[0503] Explanation of reference numerals in the attached figures

[0504] 1. Circuit board (inductor built-in circuit board); 2. 2a-2f, inductor; 3. 3a-3c, conductor; 4. 4a-4c, magnetic material; 4L, magnetic material layer; 5. Input capacitor; 6. Output capacitor; 7. 71-73, core through conductor; 8. Sealing member; 10. Substrate (core substrate); 11. First surface; 12. Second surface; 13a-13c, 14-16, through hole (core through hole); 20. 20a-20c, inductor unit cell; 21. First cell insulation portion; 22. Second cell insulation portion; 23. Insulation portion; 24, 25. Sealing insulation layer; 31. 31a-31c, 31ab 1. First electrode; 32, 32a-32c, 32bc; 2. Second electrode; 41. Magnetic through hole; 51, 61. Lower electrode; 52, 62. Upper electrode; 53. Dielectric; 81. Lower insulating layer; 82. Upper insulating layer; 83. Insulating part; 91. First insulating part; 92. Second insulating part; 100. First wiring structure; 101-103, 201-203. Insulating layer; 105, 205. Solder resist layer; 110, 120, 130, 210, 220, 230. Wiring layer; 111. First connecting electrode; 112. First inductor connecting electrode; 113. First input capacitor connecting electrode; 20 0. Second wiring structure; 211. Second inductor connection electrode; 212. Second connection electrode; 213. Second input capacitor connection electrode; 214. Output capacitor connection electrode; 300, 300a. Component embedded substrate; 400. Voltage regulation module; 410, 420. MOSFET; 500. System board; 800-805, 802a-802c, 805a-805c. Conductor containing portion; 811. First surface; 812. Second surface; 810. Substrate; 820. Through hole; 830. Through conductor; 831-833. Conductor; 831a, 832a, 833a. First side surface; 83 1b, 832b, Second side; 840, Isolation insulation layer; 841, First isolation insulation layer; 842, Second isolation insulation layer; 850, Insulation layer; 860, Insulation part; 901a, 901ab, 901bc, 901c, 902a, 902bc, First electrode; 911a, 911ab, 911bc, 911c, 912ab, 912c, Second electrode; M, First structure; CTL, Control terminal; e1, First end face; e2, Second end face; r1, Inductor configuration area; r2, Capacitor configuration area; r3, Core-through conductor configuration area; SW, SW1, SW2, Switching element.

Claims

1. A conductor-incorporated circuit substrate, wherein the conductor-incorporated circuit substrate includes: a base material having a first surface, a second surface on a side opposite to the first surface in a thickness direction, and a through-hole extending in the thickness direction; a first wiring layer disposed on the first surface of the base material; a second wiring layer disposed on the second surface of the base material; and a first conductor and a second conductor disposed in the through-hole and extending in the thickness direction, respectively, the conductor-incorporated circuit substrate further includes an isolation insulating layer in the through-hole, the isolation insulating layer being located between the first conductor and the second conductor and isolating the first conductor from the second conductor when viewed in plan view in the thickness direction.

2. The conductor-incorporated circuit substrate according to claim 1, wherein the first conductor and the second conductor are electrically isolated.

3. The conductor-incorporated circuit substrate according to claim 2, wherein the conductor-incorporated circuit substrate is configured so that electric currents flow in the first conductor and the second conductor in the thickness direction toward opposite directions from each other.

4. The conductor-incorporated circuit substrate according to claim 2, wherein the conductor-incorporated circuit substrate is configured so that electric currents flow in the first conductor and the second conductor in the thickness direction toward the same direction.

5. The conductor-incorporated circuit substrate according to claim 1, wherein the first conductor and the second conductor are electrically connected.

6. The conductor-incorporated circuit substrate according to any one of claims 1 to 5, wherein when viewed in plan view in the thickness direction, the first conductor and the second conductor face each other in a first direction with the isolation insulating layer interposed therebetween, a width of the first conductor in a second direction orthogonal to the first direction decreases as it is farther away from the second conductor in the first direction.

7. The conductor-incorporated circuit substrate according to any one of claims 1 to 6, wherein the through-hole has an elongated shape in one direction when viewed in plan view in the thickness direction.

8. The conductor-incorporated circuit substrate according to claim 7, wherein the first conductor, the second conductor, and the isolation insulating layer constitute a first structure, the first structure has an elongated shape in one direction when viewed in plan view in the thickness direction, the first structure is disposed inside the through-hole in such a manner that a length direction of the first structure coincides or substantially coincides with a length direction of the through-hole when viewed in plan view in the thickness direction.

9. The conductor-incorporated circuit substrate according to any one of claims 1 to 4, wherein the conductor-incorporated circuit substrate further includes a first inductor and a second inductor that are capable of operating independently of each other between the first wiring layer and the second wiring layer, the first inductor includes the first conductor, the second inductor includes the second conductor.

10. The conductor-incorporated circuit substrate according to any one of claims 1 to 9, wherein the first conductor and the second conductor each have: a first end portion on the first surface side electrically connected to one electrode in the first wiring layer; and a second end portion on the second surface side electrically connected to one electrode in the second wiring layer.

11. The conductor-incorporating circuit board according to any one of claims 1 to 10, wherein the conductor-incorporating circuit board further includes a third conductor disposed in the through-hole and extending in the thickness direction, the third conductor is disposed apart from the first conductor and the second conductor in the through-hole when viewed in plan view along the thickness direction.

12. The conductor-incorporating circuit board according to claim 11, wherein when viewed in plan view along the thickness direction, in the first direction, the second conductor is positioned between the first conductor and the third conductor, the separation insulating layer includes a first separation insulating layer between the first conductor and the second conductor and a second separation insulating layer between the second conductor and the third conductor.

13. The conductor-incorporating circuit board according to claim 12, wherein when viewed in plan view along the thickness direction, a width of the first conductor in a second direction orthogonal to the first direction decreases as it is farther from the second conductor along the first direction, a width of the third conductor in the second direction decreases as it is farther from the second conductor along the first direction.

14. The conductor-incorporating circuit board according to any one of claims 11 to 13, wherein the first conductor and the second conductor are electrically connected, and the third conductor is electrically separated from the first conductor and the second conductor.

15. The conductor-incorporating circuit board according to claim 14, wherein the conductor-incorporating circuit board is configured so that current flows in the same direction in the thickness direction in the first conductor and the second conductor, and current flows in the opposite direction to the first conductor and the second conductor in the third conductor.

16. The conductor-incorporating circuit board according to claim 14, wherein the conductor-incorporating circuit board is configured so that current flows in the same direction in the thickness direction in the first conductor, the second conductor, and the third conductor.

17. The conductor-incorporating circuit board according to any one of claims 11 to 13, wherein the first conductor, the second conductor, and the third conductor are electrically separated from each other.

18. The conductor-incorporating circuit board according to claim 17, wherein the conductor-incorporating circuit board is configured so that current flows in the same direction in the thickness direction in the first conductor and the second conductor, and current flows in the opposite direction to the first conductor and the second conductor in the third conductor.

19. The conductor-incorporating circuit board according to claim 17, wherein the conductor-incorporating circuit board is configured so that current flows in the same direction in the thickness direction in the first conductor, the second conductor, and the third conductor.

20. The conductor-incorporating circuit board according to any one of claims 11 to 13, wherein The first conductor, the second conductor, and the third conductor are electrically connected.

21. The conductor-incorporating circuit substrate according to claim 9, wherein The conductor-incorporating circuit substrate includes a plurality of conductor-containing portions having the base material, the first conductor, the second conductor, and the separation insulating layer, The first conductors of the plurality of conductor-containing portions are connected in series with each other to constitute the first inductor, The second conductors of the plurality of conductor-containing portions are connected in series with each other to constitute the second inductor.

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