Wiring substrate and its manufacturing method

Abstract

A wiring substrate and a method for manufacturing the same are provided. Conventional wiring substrates require increased inductance. This embodiment provides a wiring substrate comprising: a core substrate, a portion of which is composed of a magnetic resin body; and a plurality of through-hole conductors penetrating a common magnetic resin body, wherein the through-hole conductors within the magnetic resin body have an inter-conductor material with lower magnetic properties or non-magnetic properties relative to the magnetic resin body.

Description

Technical Field

[0001] This invention relates to a wiring substrate having multiple through-hole conductors and a method for manufacturing the same. Background Technology

[0002] Conventionally, as such wiring substrates, it is known that there are wiring substrates with a magnetic resin body in the core substrate and a plurality of through-hole conductors in the magnetic resin body (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-97128 ( Figure 1 )

[0004] For the aforementioned conventional wiring boards, it is necessary to increase the inductance. Summary of the Invention

[0005] A first aspect of the invention disclosed herein is a wiring substrate comprising: a core substrate, a portion of which is composed of a magnetic resin body; and a plurality of through-hole conductors that pass through a common magnetic resin body, wherein the through-hole conductors in the magnetic resin body have an interconductor material with lower magnetic properties or non-magnetic properties than the magnetic resin body.

[0006] The second aspect of the present invention is a method for manufacturing a wiring substrate, the wiring substrate comprising: a core substrate, a portion of which is composed of a magnetic resin body; and a plurality of through-hole conductors that penetrate a common magnetic resin body, wherein the through-hole conductors in the magnetic resin body are disposed between each other with an inter-conductor material having a lower magnetic strength or being non-magnetic than the magnetic resin body. Attached Figure Description

[0007] Figure 1 This is a cross-sectional view of the wiring substrate according to the first embodiment.

[0008] Figure 2A This is a cross-sectional view of the magnetic resin body. Figure 2B It is along Figure 2A A cross-sectional view along line AA.

[0009] Figure 3A This is a schematic diagram of a magnetic circuit without interconductor material. Figure 3B It is an image of a magnetic circuit with interconductor material.

[0010] Figure 4A and Figure 4B This is a cross-sectional view showing the manufacturing process of the wiring board.

[0011] Figure 5A and Figure 5B This is a cross-sectional view showing the manufacturing process of the wiring board.

[0012] Figure 6A and Figure 6B This is a cross-sectional view showing the manufacturing process of the wiring board.

[0013] Figure 7A , Figure 7B as well as Figure 7C This is a cross-sectional view showing the manufacturing process of the wiring board.

[0014] Figure 8A and Figure 8B This is a cross-sectional view showing the manufacturing process of the wiring board.

[0015] Figure 9A and Figure 9B This is a cross-sectional view showing the manufacturing process of the wiring board.

[0016] Figure 10 This is a cross-sectional view of the magnetic resin body according to the second embodiment.

[0017] Figures 11A to 11D This is a cross-sectional view showing the manufacturing process of the wiring board.

[0018] Figure 12A This is a cross-sectional view of the magnetic resin body according to the third embodiment. Figure 12B This is an enlarged cross-sectional view of the magnetic resin body. Figure 12C It is along Figure 12A A cross-sectional view of the BB line.

[0019] Figure 13A This is a cross-sectional view of the magnetic resin body according to the fourth embodiment. Figure 13B It is an image of the magnetic circuit.

[0020] Figures 14A-14C This is a cross-sectional view showing the manufacturing process of the wiring board.

[0021] Figure 15A and Figure 15B This is a cross-sectional view of the magnetic resin body of a modified wiring substrate.

[0022] Label Explanation

[0023] 10: Wiring substrate; 11: Core substrate; 12: Insulating layer (core substrate body); 32: Through-hole conductor; 32H: Through-hole; 32R: Through-hole pad; 40: Magnetic resin body; 40H: Receiving part; 43: Groove; 44: Through-hole; 50, 50A: Inter-conductor material; 51: Connecting part. Detailed Implementation

[0024] [First Implementation Method]

[0025] Reference Figures 1-9B This implementation method is described below. For example... Figure 1As shown, the wiring substrate 10 of this embodiment has, for example, a core substrate 11 and a multilayer 20 stacked on both sides of the core substrate 11.

[0026] Each stacked layer 20 has alternating layers of insulating layers 21 and conductive layers 22, and via conductors 23 connecting adjacent conductive layers 22 to each other. A solder mask layer 25 is stacked on the outermost conductive layer 22 of each stacked layer 20. The solder mask layer 25 has a plurality of openings 25H corresponding to the plurality of pads 24 included in the outermost conductive layer 22. All or part of these plurality of pads 24 have a plurality of solder bumps 26.

[0027] The core substrate 11 has an insulating layer 12. A plurality of receiving portions 40H are formed on the insulating layer 12, and magnetic resin 40 is filled in these portions 40H. The magnetic resin 40 is a resin containing magnetic particles, such as iron oxide, nickel, nickel alloys, cobalt, or tin, and the resin is such as epoxy resin or phenolic resin. The insulating layer 12 is, for example, made of a prepreg made by impregnating resin with reinforcing fibers (e.g., glass cloth), and has lower magnetism than the magnetic resin 40, or is non-magnetic.

[0028] The core substrate 11 has conductive layers 13 stacked on both sides of the insulating layer 12, which includes the magnetic resin body 40. Furthermore, as through-hole conductors connecting these conductive layers 13 to each other, a plurality of through-hole conductors 14 are provided in the non-magnetic insulating layer 12, and a plurality of through-hole conductors 32 are provided in the magnetic resin body 40. Each through-hole conductor 14, 32 has through-hole pads 14R, 32R included in the conductive layer 13 at both ends. In addition, a plurality of through-hole conductors 14, 32 are formed on the inner surfaces of a plurality of through-holes 14H, 32H penetrating the insulating layer 12 or the magnetic resin body 40, and are filled with resin 14J, 32J. Furthermore, the conductive layers 13, 22 are also connected to each other via through-hole conductors 23.

[0029] Additionally, a conductive layer 13 has a plating film 13M stacked on a metal foil 13A (e.g., copper foil). The plating film 13M, from the metal foil 13A side, consists of a first chemical plating film 13B, a first electroplated film 13C, a second chemical plating film 13D, a second electroplated film 13E, a third chemical plating film 13F, and a third electroplated film 13G. The first chemical plating film 13B and the first electroplated film 13C, as described in the manufacturing method below, serve as shielding films covering both ends of the magnetic resin body 40; the second chemical plating film 13D and the second electroplated film 13E serve as through-hole films forming multiple through-hole conductors 14 and 32; and the third chemical plating film 13F and the third electroplated film 13G serve as capping films covering the resins 14J and 32J.

[0030] As described above, each magnetic resin body 40 has a plurality of through-hole conductors 32. For example... Figure 2A As shown, the magnetic resin body 40 has an elongated oval cross-section, and a plurality of through-hole conductors 32 are arranged laterally, for example, with their central axis aligned along the center line of the width direction of the magnetic resin body 40. Furthermore, the through-hole pads 32R of these conductors 32 are circular in plan view, and their size is contained within the outer edge of the magnetic resin body 40. Each through-hole pad 32R is oriented relative to the surface of the magnetic resin body 40. Figure 2A The wiring 13S of the through-hole conductors 32 of other magnetic resin bodies 40 (not shown) are connected to the through-hole pads 32R, and an inductor 33 is formed through these through-hole conductors 32, through-hole pads 32R, and wiring 13S. Moreover, in the wiring substrate 10, in the circuit containing the inductor 33, the current flowing through the common through-hole conductors 32 of the magnetic resin body 40 is in the same direction.

[0031] like Figure 2A and Figure 2B As shown, the magnetic resin body 40 of this embodiment has an interconductor material 50 and a pair of connecting portions 51. The interconductor material 50 and the pair of connecting portions 51 are configured such that adjacent through-hole conductors 32 in the magnetic resin body 40 will bridge each other between their inner surfaces facing each other in the short side direction of the receiving portion 40H.

[0032] The interconductor material 50, for example, is quadrilateral in plan view and penetrates the magnetic resin body 40. The interconductor material 50 is disposed on an overhead line connecting the central axes of adjacent through-hole conductors 32 in the magnetic resin body 40, and its width is, for example, approximately the same as or larger than the outer diameter of the through-hole conductor 32. Furthermore, the interconductor material 50 is preferably disposed with its two ends as close as possible to the through-hole conductor 32; for example, the shortest distance L1 between the interconductor material 50 and the outer diameter of the through-hole conductor 32 is 5 μm to 15 μm.

[0033] A pair of connecting portions 51 protrude from the inner surfaces of the receiving portion 40H that are opposite each other in the width direction and are respectively connected to the conductor material 50. The pair of connecting portions 51 have the same dimensions as the conductor material 50 in the length direction of the receiving portion 40H. In addition, the pair of connecting portions 51 are disposed at the midpoint in the thickness direction of the magnetic resin body 40, and their thickness is, for example, about 1 / 2 to 1 / 5 (preferably, for example, about 1 / 3) of the magnetic resin body 40.

[0034] In addition, Figure 2B In the example shown, a pair of connecting portions 51 are disposed at the center of the magnetic resin body 40 in the thickness direction, but they can also be disposed near either side in the thickness direction. Furthermore, the pair of connecting portions 51 can be disposed at the same position in the thickness direction, but they can also be disposed at different positions.

[0035] Furthermore, in this embodiment, the interconductor material 50 and the pair of connecting portions 51 are made of an insulating layer 12, which, as described above, has lower magnetic properties than the magnetic resin body 40 or is non-magnetic.

[0036] The wiring substrate 10 of the present invention is manufactured as follows: (1) A laminate 11S is prepared in which metal foil 13A is laminated on both sides of the insulating layer 12. Furthermore, as... Figure 4A As shown, grooves 43 are formed, for example, by laser processing, at positions that serve as multiple receiving portions 40H on both sides of the laminate 11S. The grooves 43 are annular in shape, surrounding portions that will become the interconductor material 50. Furthermore, the depth of each groove 43 is, for example, approximately 1 / 5 to 1 / 3 of the thickness of the laminate 11S. Additionally, a portion of the bottom surface of the groove 43 becomes the two end faces of a pair of connecting portions 51.

[0037] (2) Next, through holes 44 are formed at both ends of the groove 43 (in other words, excluding the portions that become the conductor material 50 and the pair of connecting portions 51) by drilling. Thus, as Figure 4B As shown, a receiving portion 40H is formed inside, having an interconductor material 50 and a pair of connecting portions 51.

[0038] Furthermore, regarding the forming process of the storage section 40H, the process described in step (1) can be performed after step (2) described above. Specifically, firstly, a pair of through holes are formed in the laminate 11S by drilling. Next, on the front side of the laminate 11S, a pair of grooves are formed on both sides of the portion sandwiching the conductor interlayer material 50, in a manner that connects the pair of through holes 44 to each other. Similarly, on the back side of the laminate 11S, a pair of grooves are formed in a manner that connects the pair of through holes 44 to each other.

[0039] (3) such as Figure 5A As shown, the magnetic resin paste 40 is filled into multiple storage sections 40H by vacuum printing. Specifically, firstly, a tape (not shown) is attached to the lower end of the multiple storage sections 40H in the laminate 11S, and the magnetic resin paste 40 is filled from the upper end. Next, the upper end of the multiple storage sections 40H is closed by the tape (not shown). Then, the laminate 11S is flipped, and the tape on the upper end side is peeled off, and the magnetic resin paste 40 is filled from the upper end. As a result, the magnetic resin paste 40 is easily spread throughout the entire storage section 40H. Next, after all the tapes have been peeled off, the magnetic resin 40 is ground so that its two end faces are coplanar with the laminate 11S. As a result, the two end faces of the magnetic resin 40 are substantially coplanar with the metal foil 13A.

[0040] (4) Next, a chemical plating process and an electroplating process are performed, and a first chemical plating film 13B and a first electroplating film 13C are laminated on both sides of the laminate 11S containing the magnetic resin body 40 (see reference). Figure 5B ).

[0041] (5) such as Figure 6A As shown, through holes 14H are formed at the locations where multiple through-hole conductors 14 are formed, and a desmearing process is performed. In this desmearing process, a desmearing solution (e.g., potassium permanganate) is used to remove the desmear. In addition, the end face of the magnetic resin body 40 is covered by the first chemical plating film 13B and the first electroplating film 13C formed in the above-described (4) process, and therefore does not come into contact with the desmearing solution.

[0042] (6) Next, as Figure 6B As shown, through holes 32H are formed at the locations where multiple through-hole conductors 32 are formed, and adhesive residue removal is performed. In this adhesive residue removal process, the adhesive residue is removed not by the adhesive residue removal solution described above (5), but by medium-pressure water washing or high-pressure water washing.

[0043] (7) For example Figure 7A As shown, chemical plating and electroplating processes are performed to laminate a second chemical plating film 13D and a second electroplating film 13E onto the inner surfaces of multiple through holes 14H and 32H and onto the first electroplating film 13C. This results in multiple through-hole conductors 14 and 32.

[0044] (8) such as Figure 7B As shown, resin 14J and 32J are filled into multiple through-hole conductors 14 and 32, and the resin 14J and 32J are ground in such a way that the two end faces of the resin 14J and 32J are approximately coplanar with the second electroplated film 13E.

[0045] (9) Next, chemical plating and electroplating processes are performed. Thus, as... Figure 7C As shown, a third chemical plating film 13F and a third electroplating film 13G are formed on the second electroplating film 13E and on the exposed surfaces (end surfaces) of resins 14J and 32J.

[0046] (10) such as Figure 8A As shown, a resist 60 with a specified pattern is formed on the coated film 13M.

[0047] (11) An etching process is performed to remove the metal foil 13A and the coating film 13M exposed from the resist 60, and then the resist 60 is removed. Thus, as Figure 8B As shown, a conductive layer 13 containing multiple through-hole pads 14R and 32R is formed on both sides of the insulating layer 12 to obtain the core substrate 11.

[0048] (12) Next, by means of the SAP (Semi-Additive Process), insulating layer 21 and conductive layer 22 are alternately stacked to form a laminate 20 on both sides of the core substrate 11 (see reference). Figure 9A Additionally, in Figure 9A and Figure 9B In the image, only one layer 20 is shown.

[0049] (13) such as Figure 9B As shown, a solder mask layer 25 having multiple openings 25H is stacked on the outermost conductive layer 22. As a result, multiple pads 24 are formed that expose from the multiple openings 25H of the solder mask layer 25.

[0050] (14) Next, a plurality of solder bumps 26 are formed on part or all of the plurality of pads 24, for example, by fixing solder balls (see reference). Figure 1 Thus, wiring substrate 10 is formed.

[0051] Next, the effects of the wiring substrate 10 in this embodiment will be explained. First, the problems in the case where no inter-conductor material 50 is provided between the plurality of through-hole conductors 32 in the common magnetic resin body 40 will be explained. Figure 3A As shown, when no inter-conductor material 50 is provided between the plurality of through-hole conductors 32 in the magnetic resin body 40, when a conductor is inserted into the plurality of through-hole conductors 32 from... Figure 3A When current flows through the inner side of the paper towards the front, a counterclockwise magnetic field is generated centered on each through-hole conductor 32. At this time, the two magnetic fields are in opposite directions between adjacent through-hole conductors 32, thus creating a problem of magnetic field cancellation.

[0052] In contrast, in this embodiment, adjacent through-hole conductors 32 in the magnetic resin body 40 are provided with an inter-conductor material 50 whose magnetic properties are lower than or non-magnetic than the magnetic resin body 40. Thus, as... Figure 3B As shown, the magnetic field lines generated by the current flowing through each through-hole conductor 32 pass along the outer edge of the magnetic resin body 40, which has a higher magnetic strength than the interconductor material 50. As a result, the magnetic field is generated in a manner that surrounds the multiple through-hole conductors 32 together. That is, by placing the interconductor material 50 between the multiple through-hole conductors 32, a bypass path is formed that surrounds the multiple through-hole conductors 32 together. Thus, in this embodiment, the cancellation of the magnetic field acting between adjacent through-hole conductors 32 is reduced, and the magnetic field is strengthened compared to the past, thereby increasing the inductance compared to the past.

[0053] Furthermore, in this embodiment, the interconductor material 50 is made of the same component as the insulating layer 12, thus making it difficult to generate magnetic differences in the width direction of the bypass path of the magnetic circuit. Moreover, in this embodiment, the interconductor material 50 is fixed via a pair of connecting portions 51, thus suppressing the displacement of the interconductor material 50 during the formation of the magnetic resin body 40.

[0054] [Second Implementation]

[0055] The magnetic resin body 40 in this embodiment is as follows: Figure 10 As shown, the only difference from the first embodiment is the absence of a pair of connecting portions 51. Furthermore, the manufacturing method of the wiring board 10 in this embodiment replaces steps (1) to (3) of the first embodiment with the following steps (1) to (4). In addition, in Figures 11A to 11D In the diagram, only one magnetic resin body 40 of the wiring substrate 10 is shown.

[0056] (1) such as Figure 11A As shown, for example, multiple storage sections 40H are formed in the laminate 11S by drilling.

[0057] (2) such as Figure 11B As shown, after filling the multiple storage sections 40H with the paste of magnetic resin body 40, the front and back end faces of magnetic resin body 40 are ground to be coplanar with metal foil 13A.

[0058] (3) such as Figure 11C As shown, through holes 50H are formed, for example, by drilling, at the locations where conductor intermaterials 50 are formed in each magnetic resin body 40.

[0059] (4) such as Figure 11D As shown, after filling the through holes 50H of each magnetic resin body 40 with a paste of resin of the same material as the insulating layer 12, the front and back end faces of the conductor material 50 are ground to be coplanar with the metal foil 13A.

[0060] In this embodiment, the same effect as in the first embodiment is achieved, and since there is no pair of connecting portions 51, a uniform magnetic field is formed in the thickness direction between the plurality of through-hole conductors 32.

[0061] also, Figure 10 The conductor material 50 shown penetrates the magnetic resin body 40, but it may not, for example, penetrate it. Specifically, in the process of (3) above, a recess (not shown) is formed instead of a through hole 50H, and in the process of (4) above, the recess is filled with resin, thereby forming a conductor material that does not penetrate the magnetic resin body 40.

[0062] Furthermore, the material 50 between conductors is not limited to the same component as the insulating layer 12. It can be any material that has lower magnetic properties than the magnetic resin body 40 or is not magnetic. For example, it can be the resin 32J or air that fills the interior of the through-hole conductor 32.

[0063] [Third Implementation Method]

[0064] The magnetic resin body 40 in this embodiment is as follows: Figures 12A-12C As shown, the conductor material 50A is provided in such a way that it bridges the inner surfaces of the receiving portion 40H that are facing each other in the short side direction, and is positioned at the middle position in the thickness direction of the magnetic resin body 40, and is covered by the magnetic resin body 40 on all sides.

[0065] [Fourth Implementation Method]

[0066] The magnetic resin body 40 in this embodiment is as follows: Figure 13A , Figure 13B and Figure 14A , Figure 14B , Figure 14C As shown, for example, a plurality of first structural portions 40M extending parallel to each other and a second structural portion 40L extending in such a way as to connect one end of the plurality of first structural portions 40M are generally E-shaped when viewed from above. The first structural portions 40M, for example, are shaped such that circles with a diameter larger than the short side of the rectangle are arranged at equal intervals at multiple locations along the length of the rectangle. Through-hole conductors 32 are formed in the circular portions, and inter-conductor material 50 and a pair of connecting portions 51 are formed in the portions of the rectangle other than the circles. Furthermore, the plurality of first structural portions 40M are staggered in the positions of the through-hole conductors 32 between adjacent first structural portions 40M. The second structural portion 40L has the same width as the rectangle of the first structural portions 40M and is formed with inter-conductor material 50 and a pair of connecting portions 51.

[0067] In addition, Figure 13A , Figure 13B In the example shown, the positions of the through-hole conductors 32 in adjacent first structural portions 40M are staggered, but they can also be staggered. Furthermore, in both the first structural portion 40M and the second structural portion 40L, the width of the portion forming the through-hole conductor 32 is thicker than the other portions, but for example, the width can be approximately constant. Furthermore, in Figure 13A , Figure 13B In the second structural part 40L, in the conductor intermaterial 50, a protrusion 50T is formed from the middle part in the length direction toward the adjacent through-hole conductor 32, but for example, the protrusion 50T may not be provided.

[0068] In the wiring board 10 of this embodiment, the following steps (1) to (3) are performed instead of steps (1) to (3) of the first embodiment. (1) First, as Figure 14AAs shown, at the location where the through-hole conductor 32 is configured, multiple through holes 40E are formed, for example, by drilling.

[0069] (2) Next, as Figure 14B As shown, grooves 40F are formed, for example, by laser processing, between the through holes 40E and the portions sandwiching the conductor material 50. Thus, a receiving portion 40H is obtained by forming the conductor material 50 and a pair of connecting portions 51 between adjacent through holes 40E.

[0070] (3) Next, as Figure 14C As shown, magnetic resin 40 is filled into the receiving section 40H. The filling of magnetic resin 40 is the same as the process in (3) of the first embodiment, and a tape is preferably used. In addition, the filling of magnetic resin 40 is performed by a dispenser instead of vacuum printing. Afterwards, the front and back end faces of magnetic resin 40 are ground to be coplanar with a metal foil (not shown). Thus, magnetic resin 40 is obtained.

[0071] According to this embodiment, such as Figure 13B As shown, a bypass path is formed that surrounds the plurality of through-hole conductors 32 included in the first structural part 40M, achieving the same effect as in the first embodiment.

[0072] [Other Implementation Methods]

[0073] In the first to third embodiments described above, an example in which the common magnetic resin body 40 has two through-hole conductors 32 was described, but the number of through-hole conductors 32 included in the common magnetic resin body 40 may also be three or more.

[0074] The shape of the magnetic resin body 40 is not limited to an oblong or elliptical shape when viewed from above, such as... Figure 15A and Figure 15B As shown, it can also be a quadrilateral, a circle, etc. when viewed from above.

[0075] The shape of the interconductor material 50 is not limited to a quadrilateral when viewed from above, such as... Figure 13A , Figure 13B and Figure 15B As shown, it can also be polygonal, circular, irregularly shaped, etc. Furthermore, the connecting portion 51 that connects to the conductor material 50 is not limited to a pair; it can be only one or more than three (see reference). Figure 15B ).

[0076] Furthermore, specific examples of the technology included in the claims are disclosed in this specification and the accompanying drawings, but the technology described in the claims is not limited to these specific examples, and also includes examples obtained by various modifications and alterations to the specific examples, as well as examples obtained by taking a part of the specific examples separately.

Claims

1. A wiring substrate, comprising: The core substrate, a portion of which is composed of magnetic resin; and Multiple through-hole conductors that pass through a common magnetic resin body. in, The through-hole conductors in the magnetic resin body have an interconductor material with lower magnetic properties or non-magnetic properties than the magnetic resin body.

2. The wiring substrate according to claim 1, wherein, The circuitry contained in the wiring substrate is configured such that current flows in the same direction through the adjacent through-hole conductors sandwiched between the conductor materials.

3. The wiring substrate according to claim 1, wherein, The material between the conductors is the same component as the main body of the core substrate, except for the magnetic resin body.

4. The wiring substrate according to claim 3, wherein, The wiring substrate has a connecting portion that protrudes from the core substrate body into the magnetic resin body and is connected to the conductor material.

5. The wiring substrate according to claim 4, wherein, The connecting portion is positioned midway along the thickness direction of the core substrate body.

6. The wiring substrate according to claim 1, wherein, The interconductor material is resin that fills the through holes or recesses formed in the magnetic resin body.

7. A method for manufacturing a wiring substrate, the wiring substrate comprising: The core substrate, a portion of which is composed of magnetic resin; and Multiple through-hole conductors that pass through a common magnetic resin body. in, The through-hole conductors in the magnetic resin body are disposed between each other with an interconductor material that is less magnetic than or non-magnetic than the magnetic resin body.

8. The method for manufacturing a wiring substrate according to claim 7, comprising the following steps: A storage portion is formed in the main body of the core substrate, excluding the magnetic resin body; The magnetic resin body is filled into the receiving portion; and The plurality of through-hole conductors are formed in the magnetic resin body. In the process of forming the storage portion, the connecting portion extending inward from the inner surface of the storage portion and the conductor material integrally formed with the front end of the connecting portion remain in the storage portion as part of the core substrate body portion.

9. The method for manufacturing a wiring substrate according to claim 8, wherein, The process of forming the storage section includes the following steps: In the first step, an annular groove is formed on both sides of the main body of the core substrate, surrounding the portion that becomes the material between the conductors; as well as In the second step, a plurality of through holes overlapping the groove are formed separately from each other, and between the through holes, there is a conductor material of the same height as the overall height of the core substrate body and a connecting portion disposed at a midway position in the thickness direction of the core substrate body.

10. The method for manufacturing a wiring substrate according to claim 9, wherein, In the first step, the groove is formed by laser processing. In the second step, the plurality of through holes are formed by drilling.

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