JP2016162977A - Wiring board and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board which achieves excellent component mountability in a recessed part.SOLUTION: A wiring board (10) includes: wiring layers (16) which are laminated; an insulation layer (18-4) having a surface (17) and a surface (19) on which a wiring layer (16-4) and a wiring layer (16-5) of the wiring layers (16) are respectively provided; a cavity (24) which is recessed from a surface (17) side to a middle part of the insulation layer (18-4); and a connection part (22-4) which is electrically connected with the wiring layer (16-5) and is provided at the insulation layer (18-4) so as to be exposed on a bottom surface of the cavity (24). The connection part (22-4) has: an exposed surface (26) exposed on the bottom surface of the cavity (24); a connection surface (28) which contacts with the wiring layer (16-5); and a side surface (30) which contacts with the insulation layer (18-4). The side surface (30) inclines.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique effective when applied to a wiring board and a manufacturing method thereof.

  Japanese Patent Laying-Open No. 2004-326441 (hereinafter referred to as “Patent Document 1”) describes a technique for connecting a capacitor in a cavity using a through hole exposed on the bottom surface of the cavity as a connecting portion.

Japanese Patent Laid-Open No. 2004-326441

  As electronic products including wiring boards and electronic components (for example, passive components such as semiconductor chips and chip capacitors) mounted on them are miniaturized (including thinning) and highly functional, wiring boards are also devised. It has been demanded. For example, the wiring board itself can be made thinner, and the wiring pattern (wiring layer) can be made finer and denser. Further, regarding the mounting position of the electronic component, not only on the substrate plane, but also a device for mounting inside the substrate is formed by forming a recess (cavity) for mounting (accommodating) the electronic component. As a wiring board having a recess for mounting an electronic component, for example, as in the technique described in Patent Document 1, a recess for mounting an electronic component is formed by counterbore processing. Some of them are used as connection parts with parts.

  However, when dealing with the thinning of the wiring board, in the technique described in Patent Document 1, the length of the through hole (distance in the board thickness direction) is simply shortened, and the adhesion with the interlayer insulating layer of the wiring board is reduced. Depending on the conditions under which the through hole is stressed by being bonded to the electronic component, there is a possibility that a malfunction (for example, peeling) may occur. In the technique described in Patent Document 1, the end face of the through hole is exposed and connected (joined) to the electronic component, but the size and shape (circular shape) of the exposed face (connecting face) are in the through hole itself. Therefore, it is restricted and cannot cope with miniaturization and various shapes (for example, a rectangular shape such as a rectangular shape). Moreover, in the technique described in Patent Document 1, there is a risk that when forming the concave part for mounting an electronic component, a copper thin film on the inner wall surface is peeled off due to processing stress on the through hole.

  The objective of this invention is providing the wiring board excellent in the component mounting property in a recessed part. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  A wiring board according to one solution of the present invention includes a plurality of wiring layers to be stacked, an insulating layer having first and second surfaces on which the first and second wiring layers of the plurality of wiring layers are respectively provided; A concave portion that is recessed from the first surface side to the middle of the insulating layer, and a connection portion that is electrically connected to the second wiring layer and is provided on the insulating layer so as to be exposed at the bottom surface of the concave portion, The connection portion has an exposed surface exposed at a bottom surface of the recess, a connection surface in contact with the second wiring layer, and a side surface that intersects the exposed surface and the connection surface and contacts the insulating layer, The side surface is inclined.

  According to this, since the side surface of the connection part in the insulating layer is inclined, the contact area with the insulating layer is larger than that of the non-inclined one, so that the adhesion of the connection part can be improved. . For this reason, for example, even when the substrate is thinned, it is possible to prevent the connection portion from being removed. That is, even if an electronic component is mounted in the recess, it is possible to provide a wiring board excellent in component mounting property that ensures connection reliability with the connection portion.

  In the wiring board according to the embodiment, it is more preferable that the connection portion has a shape that spreads from the first surface side to the second surface side. According to this, since the connection portion has a shape that widens at the end, the connection portion can be more difficult to be removed from the bottom surface of the recess.

  In the wiring board according to the embodiment, it is more preferable that the connection portion has a shape that is narrowed from the first surface side to the second surface side. In this way, if the connecting portion has a shape that narrows the bottom, the exposed surface (connecting surface) can be enlarged while securing a connecting surface of a desired size, so that the connection reliability with the component is further ensured. be able to.

  In the wiring board according to the embodiment, the connection portion electrically connects the first wiring layer and the second wiring layer, and the first wiring layer and the second wiring layer are connected to each other. The first surface side end of the connecting portion is provided between the first surface side end by the recess while a part of the first surface side end portion is in contact with the first wiring layer. More preferably, the exposed surface is provided by shaving the other part of the part. According to this, since the connection portion remains sandwiched between the first wiring layer and the second wiring layer, it is possible to prevent the connection portion from coming off even when the substrate is thinned. .

  In the wiring board according to the embodiment, it is more preferable that the exposed surface has a rectangular shape in which the direction from the center of the bottom surface of the recess to the outer periphery of the bottom surface is a longitudinal direction. It is more preferable that a plurality are provided along the bottom edge of the recess. According to this, for example, an electronic component is mounted on the center of the bottom surface of the recess, and wire bonding from the electronic component to the connection portion is facilitated.

  The wiring board according to the embodiment includes a surface layer provided on a substrate surface so as to expose the recess and cover the first wiring layer, and the surface layer is larger than an opening of the recess. It is more preferable to have an enlarged opening that is open. According to this, for example, when resin-sealing an electronic component mounted in the recess, the resin can be stopped by the stepped portion between the opening of the recess and the opening of the enlarged opening.

  The wiring board according to the embodiment more preferably includes a through portion that penetrates the insulating layer at the bottom surface of the recess. According to this, for example, a heat radiating plate can be provided on the substrate, and the heat radiating property of the electronic component can be enhanced through the through portion.

  In the wiring substrate according to the embodiment, the insulating layer is a first insulating layer, the concave portion is a first concave portion, the connecting portion is a first connecting portion, and the third and third wiring layers are formed. A second insulating layer having third and fourth surfaces provided with four wiring layers, a second recess recessed from the third surface side to the middle of the second insulating layer, and the fourth wiring layer electrically And a second connection portion provided in the second insulating layer so as to be exposed at the bottom surface of the second recess, wherein the first, second, third, and fourth wiring layers are in this order. The second insulating layer is stacked, and the second connecting portion intersects the exposed surface exposed at the bottom surface of the second recess, the connecting surface in contact with the third wiring layer, the exposed surface and the connecting surface, and the second insulating layer. A side surface of the second connection portion is inclined, and the first connection portion is inclined from the first surface side to the second side. The second connecting portion has a shape that narrows from the third surface side to the fourth surface side, and the first connecting portion extends from the first surface side to the second surface. It is more preferable that the second connecting portion has a shape that spreads from the third surface side to the fourth surface side when the shape is narrowed to the surface side. Furthermore, it is more preferable that the first recess is opened in one direction of the substrate thickness, and the second recess is opened in a direction opposite to the one direction. According to this, it is possible to further ensure the connection reliability with the electronic component or to make it difficult to remove the connection portion in correspondence with the plurality of electronic components to be mounted.

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows. According to one solution of the present invention, it is possible to provide a wiring board that is excellent in component mounting properties in a recess.

1 is a schematic plan view of a wiring board according to an embodiment of the present invention. It is typical sectional drawing of the wiring board corresponding to the II-II line shown in FIG. FIG. 2 is a schematic cross-sectional view showing a state where electronic components are mounted on the wiring board shown in FIG. 1. FIG. 2 is a schematic cross-sectional view showing a state where electronic components are mounted on the wiring board shown in FIG. 1. FIG. 2 is a schematic cross-sectional view showing a state where electronic components are mounted on the wiring board shown in FIG. 1. It is a typical sectional view of a wiring board of a manufacture process concerning one embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 6. FIG. 8 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 7. FIG. 9 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 8. FIG. 10 is a schematic cross-sectional view of the wiring board in the manufacturing process subsequent to FIG. 9. FIG. 11 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 10. FIG. 12 is a schematic cross-sectional view of the wiring board in the manufacturing process subsequent to FIG. 11. FIG. 13 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 12. It is typical sectional drawing of the wiring board which the present inventors examined. It is a typical sectional view of a wiring board concerning other embodiments of the present invention. It is typical sectional drawing of the wiring board of the manufacture process which concerns on other embodiment of this invention. FIG. 17 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 16. FIG. 18 is a schematic cross-sectional view of a wiring board in a manufacturing process subsequent to FIG. 17. FIG. 19 is a schematic cross-sectional view of the wiring board in the manufacturing process subsequent to FIG. 18. FIG. 20 is a schematic cross-sectional view of the wiring board in the manufacturing process subsequent to FIG. 19. FIG. 21 is a schematic cross-sectional view of the wiring board in the manufacturing process subsequent to FIG. 20. It is a typical sectional view of a wiring board concerning other embodiments of the present invention. It is a typical sectional view of a wiring board concerning other embodiments of the present invention. It is a typical sectional view of a wiring board concerning other embodiments of the present invention. It is a typical sectional view of a wiring board concerning other embodiments of the present invention. It is a typical sectional view of a wiring board concerning other embodiments of the present invention.

  In the following embodiments of the present invention, the description will be divided into a plurality of sections when necessary. However, in principle, they are not irrelevant to each other, and one of them is related to some or all of the other modifications, details, etc. It is in. For this reason, the same code | symbol is attached | subjected to the member which has the same function in all the figures, and the repeated description is abbreviate | omitted. In addition, the number of components (including the number, numerical value, quantity, range, etc.) is limited to that specific number unless otherwise specified or in principle limited to a specific number in principle. It may be more than a specific number or less. In addition, when referring to the shape of a component, etc., it shall include substantially the same or similar to the shape, etc., unless explicitly stated or in principle otherwise considered otherwise .

(Embodiment 1)
The structure of the wiring board 10 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view of the wiring board 10. FIG. 2 is a schematic cross-sectional view of the wiring board 10 corresponding to the II-II line shown in FIG. 3 to 5 are schematic cross-sectional views of the state in which the electronic components 12 and 13 are mounted on the wiring board 10 (electronic product 14).

  The wiring board 10 is a multilayer wiring board (in FIG. 2, a six-layer multilayer wiring board) including a plurality of wiring layers 16 to be stacked. In addition, the wiring substrate 10 includes a plurality of insulating layers 18 (interlayer insulating layers) provided between the wiring layers 16 and a substrate surface (a main surface and a back surface opposite to the main surface) so as to cover the plurality of wiring layers 16. And a plurality of connection portions 22 provided on the insulating layer 18 and electrically connected to the wiring layer 16. The upper surface of the substrate will be described as the main surface and the lower surface of the substrate will be described as the back surface. However, depending on the state of use, the upper and lower surfaces of the substrate may be reversed.

  In the present embodiment, as shown in FIG. 2 and the like, in order to distinguish the two surface layers 20, reference numerals are assigned as the surface layer 20U on the upper surface (main surface) side and the surface layer 20L on the lower surface (back surface) side. ing. Further, the six wiring layers 16 are sequentially denoted by the wiring layers 16-1, 16-2, 16-3, 16-4, 16-5, 16-6 from the upper surface side, and five insulating layers 18 are provided. Are numbered as insulating layers 18-1, 18-2, 18-3, 18-4, and 18-5 in order from the upper surface side. In addition, the five layers of connection portions 22 provided in each of the insulating layers 18-1, 18-2, 18-3, 18-4, and 18-5 are connected to the connection portions 22-1, 22-2, 22-3, and 22 respectively. Reference numerals -4 and 22-5 are assigned.

  In addition, the wiring board 10 includes a cavity 24 (recessed portion) for mounting electronic components that is recessed from the upper surface side (surface layer 20U side). In the present embodiment, the cavity 24 is recessed to the middle of the insulating layer 18-4 having the upper surface 17 on which the wiring layer 16-4 is provided and the lower surface 19 on which the wiring layer 16-5 is provided. The bottom surface (bottom portion) of the cavity 24 is provided in the insulating layer 18-4. At the bottom surface of the cavity 24, the connection portion 22-4 that is electrically connected to the wiring layer 16-5 is exposed.

  The connecting portion 22-4 has an exposed surface 26 exposed at the bottom surface of the cavity 24, a connecting surface 28 that contacts the wiring layer 16-5, a side surface that intersects the exposed surface 26 and the connecting surface 28, and contacts the insulating layer 18-4. 30 and the side surface 30 is inclined. Here, as shown in FIGS. 3 to 5, the exposed surface 26 of the connection portion 22-4 exposed at the bottom surface of the cavity 24 is a connection surface (connection pad P <b> 1, P2). The electronic component 12 and the electronic component 13 are accommodated in the cavity 24 in a state where they are stacked with an adhesive, for example, and mounted on the wiring board 10. The electronic component 12 is electrically connected (flip-chip connection) to the connection portion 22-4 (circular connection pad P1 shown in FIG. 1) of the wiring substrate 10 via the connection bumps 32. Further, the electronic component 13 is electrically connected (wire bonding connection) to the connection portion 22-4 (rectangular connection pad P2 shown in FIG. 1) of the wiring board 10 through the bonding wire 34.

  In such a wiring board 10, the side surface 30 of the connecting portion 22-4 in the insulating layer 18-4 is inclined, so that it is insulated as compared with the case where the side surface 30 is not inclined (the side surface is straight in the substrate thickness direction). Since the contact area with the layer 18-4 becomes large, the adhesion of the connecting portion 22-4 can be improved. For this reason, for example, even when the wiring board 10 is thinned, it is possible to prevent the connecting portion 22-4 from being removed. That is, even when the electronic components 12 and 13 are mounted in the cavity 24, it is possible to provide the wiring board 10 excellent in component mounting property that ensures connection reliability with the connection portion 22-4.

  In the present embodiment, the connecting portion 22-4 whose side surface 30 is inclined has a shape that spreads from the surface 17 side to the surface 19 side of the insulating layer 18-4 as shown in FIG. For this reason, the area of the connection surface 28 is larger than the area of the exposed surface 26 of the connection part 22-4. Since the connecting portion 22-4 has a shape that widens at the end, the connecting portion 22-4 can be more difficult to be removed from the bottom surface of the cavity 24.

  Here, the connection part 22-4 which becomes the connection pad P1 for flip chip connection can also be configured from a through hole (connection part 22-3) which will be described later (described later). Therefore, the pad area is relatively large in the through hole. For example, as shown in FIG. 2, the diameter φb of the connection portion 22-3 (through hole) is larger than the diameter φa of the connection portion 22-4. Since it is necessary to miniaturize the connection pad P1 in order to cope with the miniaturization of the electronic component 12, the connection portion 22-4 (the one of the connection pad P1) is used, for example, using a laser capable of miniaturization instead of a drill. It is preferable to form a truncated cone-shaped penetrating portion and a connection pad P2 having a plate shape and a truncated pyramid-shaped penetrating portion.

  Further, in the present embodiment, at the end portion on the surface 17 side (the upper end portion in FIG. 2) of the connection portion 22-4, the other end portion on the surface 17 side is in contact with the wiring layer 16-4 by the cavity 24. The exposed portion 26 (connection pad P2) is provided by cutting the portion. According to this, since the connection portion 22-4 constituting the connection pad P2 remains sandwiched between the wiring layer 16-4 and the wiring layer 16-5, even when the wiring board 10 is thinned. It will be prevented from coming off.

  Further, in the present embodiment, the exposed surface 26 of the connection portion 22-4 that becomes the connection pad P2 has a rectangular shape in which the direction from the center of the bottom surface of the cavity 24 to the outer periphery of the bottom surface is long as shown in FIG. . In other words, the connection portion 22-4 that becomes the connection pad P2 is formed in a plate shape (square pyramid shape) with respect to the truncated cone shape of the connection portion 22-4 that becomes the connection pad P1. The plate-like connecting portion 22-4 is provided so as to be inserted into the insulating layer 18-4 and has improved adhesion with the insulating layer 18-4. For example, when the wiring board 10 is thinned Even so, it is possible to prevent the connecting portion 22-4 from being removed.

  Further, a plurality of connection portions 22-4 serving as the connection pads P <b> 2 are provided so as to intersect on the longitudinal side along the bottom edge of the cavity 24. In the present embodiment, when the electronic component 13 is mounted on the central portion of the bottom surface of the cavity 24 and electrically connected to the connection pad P2 of the wiring board 10, the central portion of the bottom surface on which the electronic component 13 is mounted is changed to the outer peripheral portion of the bottom surface. The bonding wire 34 is stretched. For this reason, wire bonding from the electronic component 13 to the connection pad P2 (connection part 22-4) becomes easy by providing the rectangular connection pad P2 (connection part 22-4) whose extending direction is long. .

  In the present embodiment, the surface layer 20 </ b> U provided on the substrate surface so as to expose the cavity 24 and cover the wiring layer 16 has an enlarged opening 36 that is opened larger than the opening of the cavity 24. By providing the enlarged opening 36, a stepped portion 38 is formed by the opening edge of the cavity 24 and the opening edge of the enlarged opening 36. Therefore, for example, when the electronic parts 12 and 13 mounted in the cavity 24 are resin-sealed by potting using a dispenser, the sealing resin 40 is resinated by the stepped portion 38 as shown in FIG. It can be stopped. In the case of resin molding using a molding die, as shown in FIG. 5, the sealing resin 40 enters the cavity 24 and the stepped portion 38, so that the wiring substrate 10 and the sealing resin 40 are in close contact with each other. Can be improved.

  Next, a method for manufacturing the wiring substrate 10 according to the first embodiment of the present invention will be described with reference to FIGS. 2 and 6 to 13. 6 to 13 are schematic cross-sectional views of the manufacturing process of the wiring board 10 (see FIG. 2).

  First, as shown in FIG. 6, a core material 42 having an insulating layer 18-3 and wiring layers 16-3 and 16-4 provided on both surfaces thereof is prepared. The insulating layer 18-3 is made of, for example, an insulating resin (for example, an epoxy resin) that encloses a glass fiber cloth. Moreover, the wiring layers 16-3 and 16-4 are made of, for example, copper foil.

  Subsequently, after forming a through hole 44 (indicated by a broken line in FIG. 6) in the core material 42, as shown in FIG. 7, a connection portion 22-3 is formed in the through hole 44 and patterned. Wiring layers 16-3 and 16-4 are formed. By this patterning, a circuit is formed in the wiring layer 16-3. The connection part 22-3 is composed of, for example, a through hole. In forming the through hole, first, a through hole 44 is formed using a drill, and a plating film is formed on the inner wall surface by plating (for example, copper plating). Next, the through hole 44 is filled with an insulating material 46 (for example, insulating resin), and cover plating (for example, copper plating) is performed as necessary so as to cover both ends of the through hole 44, thereby connecting portions 22-3 ( Through hole) is formed. Next, for example, the wiring layers 16-3 and 16-4 are patterned by a subtractive method to form a circuit. The through hole 44 may be formed by laser processing. Further, the through hole 44 may be embedded using a conductive material (for example, copper plating) instead of the insulating material 46.

  Then, as shown in FIG. 8, the insulating layer 18-2 provided with the wiring layer 16-2 is laminated on the upper surface of the insulating layer 18-3, and the insulating layer 18-4 provided with the wiring layer 16-5 is provided. Is laminated on the lower surface of the insulating layer 18-3. For example, these layers are laminated by thermocompression bonding such that the insulating layer 18-3 is sandwiched between the insulating layers 18-2 and 18-4. Thereby, the wiring layer 16-3 is covered with the insulating layer 18-2, and the wiring layer 16-4 is covered with the insulating layer 18-4. The insulating layers 18-2 and 18-4 are made of, for example, an insulating resin (for example, an epoxy resin). The wiring layers 16-2 and 16-5 are made of, for example, copper foil.

  Subsequently, as illustrated in FIG. 9, a penetrating portion 48 that reaches the wiring layer 16-3 from the upper surface side of the insulating layer 18-2 and has an inclined inner wall surface is formed in the insulating layer 18-2. In addition, penetrating portions 50 and 52 are formed in the insulating layer 18-4 that reach the wiring layer 16-4 from the lower surface side of the insulating layer 18-4 and in which the inner wall surface is inclined. The processing method of the penetrating portions 48, 50, and 52 is not particularly limited, but in this embodiment, laser processing with a high degree of freedom in the processing shape is used. Further, by using a conformal mask, processing accuracy can be ensured. Therefore, a laser (for example, carbon dioxide laser) is irradiated using the opened wiring layers 16-2 and 16-5 as a conformal mask to form a through-hole 48 in the insulating layer 18-2, and the insulating layer 18-4 The through portions 50 and 52 are formed.

  According to the laser processing, the opening is slightly wide on the laser incident side, and the opening is narrowed so that the bottom is narrowed, so that the through portions 48, 50, and 52 are formed. Thereby, it forms so that the inner wall face of the penetration parts 48, 50, and 52 may incline. The penetrating part 50 is formed in a truncated cone-shaped through hole, and the penetrating part 52 has a desired shape so as to be formed in a quadrangular pyramid-shaped penetrating groove. The through-holes 50 and 52 constitute a connection pad P1 for flip chip connection and a connection pad P2 for wire bonding connection by counterbore processing after a conductive member is embedded in a later step. (See FIG. 2).

  Subsequently, as illustrated in FIG. 10, a conductive material is embedded in the through portion 48 to form a connection portion 22-2 (Filled Via) that is electrically connected to the wiring layer 16-3, and the connection portion 22-2 is formed. Then, a patterned wiring layer 16-2 is formed on the upper surface of the insulating layer 18-2. By this patterning, a circuit is formed in the wiring layer 16-2. Further, a conductive material is embedded in the through portions 50 and 52 to form a connection portion 22-4 (Filled Via) that is electrically connected to the wiring layer 16-4, and is electrically connected to the connection portion 22-4. Thus, a patterned wiring layer 16-5 is formed on the lower surface of the insulating layer 18-4. By this patterning, a circuit is formed in the wiring layer 16-5. The patterning method of the wiring layers 16-2 and 16-5 is not particularly limited, but in this embodiment, a subtractive method is used.

  As the conductive material embedded in the through portions 48, 50, and 52, for example, copper plating can be used. In the case of copper plating, after the desmear treatment is performed on the inner wall surfaces of the through portions 48, 50, 52 as necessary as in the case of so-called via fill plating, electroless copper plating and electrolytic copper plating are performed in this order. Then, the connecting portions 22-2 and 22-4 are formed. The connection portions 22-2 and 22-4 are formed by embedding electrolytic copper plating in the through portions 48, 50 and 52 in which an electroless copper plating film is formed on the inner wall surface.

  Subsequently, as shown in FIG. 11, the insulating layer 18-1 provided with the wiring layer 16-1 is laminated on the upper surface of the insulating layer 18-2, and the insulating layer 18-5 provided with the wiring layer 16-6. Is laminated on the lower surface of the insulating layer 18-4. For example, the insulating layers 18-2, 18-3, and 18-4 are laminated by being thermocompression bonded so as to be sandwiched between the insulating layers 18-1 and 18-5. As a result, the wiring layer 16-2 is covered with the insulating layer 18-1, and the wiring layer 16-5 is covered with the insulating layer 18-5. The insulating layers 18-1 and 18-5 are made of, for example, an insulating resin (for example, an epoxy resin). Moreover, the wiring layers 16-1 and 16-6 are made of, for example, copper foil.

  Subsequently, as illustrated in FIG. 12, a connection portion 22-1 (Filled Via) electrically connected to the wiring layer 16-2 is formed, and the connection portion 22-1 is electrically connected. A patterned wiring layer 16-1 is formed on the upper surface of the insulating layer 18-1. Further, a connection portion 22-5 (Filled Via) electrically connected to the wiring layer 16-5 is formed, and is formed on the lower surface of the insulating layer 18-5 so as to be electrically connected to the connection portion 22-5. A patterned wiring layer 16-6 is formed. Circuit formation is performed in the wiring layers 16-1 and 16-6 by this patterning. In addition, these are formed in the process similar to the process demonstrated with reference to FIG. 9 and FIG. 10, for example.

  Subsequently, as shown in FIG. 13, a surface layer 20 </ b> U serving as a substrate surface (main surface) was laminated on the upper surface of the insulating layer 18-1, and was opened larger than the opening of the cavity 24 (see FIG. 2). The surface layer 20U patterned so as to have the enlarged opening 36 is formed. As a result, the wiring layer 16-1 is covered with the surface layer 20 U, and the insulating layer 18-1 is exposed from the enlarged opening 36. Further, a surface layer 20L to be a substrate surface (back surface) is laminated on the insulating layer 18-5. Thereby, the wiring layer 16-6 is covered with the surface layer 20L. The surface layers 20U and 20L are made of, for example, a solder resist.

  Subsequently, as shown in FIG. 2, the insulating layer 18-1, 18-2, 18-3 is penetrated from the surface layer 20U side, and the middle of the insulating layer 18-4 (that is, the fourth wiring layer 16-). A cavity 24 (concave portion) that is recessed to the fourth and fifth wiring layers 16-5) is formed. Thus, the exposed surface 26 exposed at the bottom surface of the cavity 24, the connection surface 28 in contact with the wiring layer 16-5, and the side surface 30 intersecting the exposed surface 26 and the connection surface 28 and in contact with the insulating layer 18-4 are provided. A plurality of connection portions 22-4 are formed. Among the plurality of connection portions 22-4, the one formed in the through portion 50 constitutes a connection pad P1 for flip chip connection, and the one formed in the through portion 52 constitutes a connection pad P2 for wire bonding connection. To do. Further, in the connection portion 22-4 constituting the connection pad P2, by forming the cavity 24, a part of the end portion on the surface 17 side of the insulating layer 18-4 of the connection portion 22-4 becomes the wiring layer 16-4. The exposed surface 26 is formed by scraping the other part while in contact. Thereafter, general surface treatment such as oxidation prevention of the connection pads P1 and P2 is performed, and the wiring board 10 is substantially completed. Further, it is divided into shipping sizes as necessary, and is shipped through a cleaning and inspection process.

  In this embodiment, a counterboring process (cutting process) is used as a processing method of the cavity 24. For example, the cavity 24 can be formed together with the surface layer 20U without the enlarged opening 36, but if counterbore processing is used, shavings may remain around the opening in the surface layer 20U. Therefore, in the present embodiment, after forming the surface layer 20U having the enlarged opening 36 that opens larger than the opening of the cavity 24, the cavity 24 is formed by counterbore processing in the enlarged opening 36, and the shavings are formed. Is prevented from occurring. The cavity 24 may be formed before the surface layer 20U is formed, and then the surface layer 20U having the enlarged opening 36 may be formed.

  In the present embodiment, the connection portion 22-4 constituting the connection pads P1 and P2 extends from the upper surface 17 where the wiring layer 16-4 is provided to the lower surface 19 where the wiring layer 16-5 is provided. It becomes the shape which spreads at the end, and the side surface 30 becomes inclined. This is composed of a conductive member embedded in the through portions 50 and 52 in which the connecting portion 22-4 is formed in a desired shape by laser processing, and by the counterboring process performed halfway through the insulating layer 18-4, This is because part of the connecting portion 22-4 (the side where the openings of the through portions 50 and 52 are narrow) is cut out.

  Here, the difference between the wiring board 10 shown in FIG. 2 and the wiring board 500 shown in FIG. 14 will be described. FIG. 14 is a schematic cross-sectional view of a wiring board 500 examined by the present inventors. These are different in that the connection pads P1 and P2 provided on the bottom surface of the cavity 24 are the connection portion 22-4 in the wiring substrate 10 and the wiring layer 16-4 in the wiring substrate 500. The connection pads P1 and P2 are formed (exposed) by forming the cavity 24 as described above.

  In the wiring substrate 500, when the wiring layer 16-4 is cut out by counterboring to form the connection pads P1 and P2, the depth accuracy (mechanical accuracy) of the counterboring processing, the processing stress (damage to the wiring layer 16-4) ) Is a problem. In particular, in the case of the miniaturized wiring layer 16-4, the thickness thereof is also reduced. Therefore, very high processing accuracy is required for the formation of the cavity 24, and the substrate thickness variation is required for processing with high accuracy. There is also a need to suppress. However, it is difficult to evenly cut the wiring layer 16-4 with the accuracy of counterbore processing (here, the accuracy in which the thickness obtained by subtracting the desired thickness from the thickness of the wiring layer 16-4 is acceptable). In addition, since the connection pads P1 and P2 are also extremely thin (location A in FIG. 14), there is a possibility that problems such as peeling due to processing stress may occur. In order to improve the processing stress resistance, it is conceivable to increase the width of the wiring layer 16-4 (the width of the cavity 24 as viewed from the bottom), but it becomes impossible to cope with miniaturization.

  Therefore, even when the counterbore process is used when forming the cavity 24 in the wiring substrate 10, the connection pad P1, the connection portion 22-4 is formed in the thickness direction of the insulating layer 18-4. The allowable machining accuracy for cutting out a part of the connecting portion 22-4 constituting the P2 can be remarkably reduced. Further, the side surface 30 of the connection portion 22-4 is formed to be inclined and the contact area with the insulating layer 18-4 is increased, so that the connection portion 22-4 does not easily peel off due to processing stress. Yes. Further, since the connection portion 22-4 constituting the connection pad P2 for wire bonding connection is sandwiched between the wiring layer 16-4 and the wiring layer 16-5, the structure is excellent in processing stress. It has become.

  With such a manufacturing technique of the wiring board 10, a wiring pattern that can withstand the counterboring process can be formed, and, for example, a wiring pattern finer than that of the wiring board 500 can be formed. Moreover, in the manufacturing technique of the wiring board 10, since the wiring structure can accept the machining accuracy of the counterboring process and the board thickness variation, the manufacturing yield (processing yield) can be improved. Moreover, even if the size of the cavity 24 is enlarged as necessary, these effects can be obtained.

(Embodiment 2)
A wiring board 10A according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 15 is a schematic plan view of the wiring board 10A. 16 to 21 are schematic cross-sectional views of the manufacturing process of the wiring board 10A. In contrast to the first embodiment, in the present embodiment, the connection portion 22-2 having the exposed surface 26 that constitutes the connection pads P1 and P2 has a shape that narrows from the exposed surface 26 side to the opposite surface side. They are different (see FIG. 15). Below, it demonstrates centering around difference.

  The wiring board 10A is a multilayer wiring board (in FIG. 15, a six-layer multilayer wiring board) including a plurality of wiring layers 16 to be stacked. This wiring board 10A includes an electronic component mounting cavity 24 (recessed portion) that is recessed from the upper surface side (surface layer 20U side). In the present embodiment, the cavity 24 is recessed to the middle of the insulating layer 18-2 having the upper surface 54 on which the wiring layer 16-2 is provided and the lower surface 56 on which the wiring layer 16-3 is provided. The bottom surface (bottom part) of the cavity 24 is provided in the insulating layer 18-2. At the bottom surface of the cavity 24, the connection portion 22-2 that is electrically connected to the wiring layer 16-3 is exposed.

  The connection portion 22-2 includes an exposed surface 26 exposed at the bottom surface of the cavity 24, a connection surface 28 in contact with the wiring layer 16-3, and a side surface that intersects the exposed surface 26 and the connection surface 28 and contacts the insulating layer 18-2. 30 and the side surface 30 is inclined. Here, the exposed surface 26 of the connection portion 22-2 exposed at the bottom surface of the cavity 24 is, for example, a connection surface (connection pads P1, P2) electrically connected to the electronic components 12, 13 as shown in FIG. ) Also in this embodiment, as shown in FIG. 1, the flip-chip connection pad P1 has a circular shape, and the wire bonding connection pad P2 has a rectangular shape.

  In such a wiring board 10A, the side surface 30 of the connecting portion 22-2 in the insulating layer 18-2 is inclined, so that it is insulated as compared with the case where the side surface 30 is not inclined (the side surface is straight in the substrate thickness direction). Since the contact area with the layer 18-2 becomes large, the adhesiveness of the connection part 22-2 can be improved. For this reason, for example, even when the wiring board 10A is thinned, it is possible to prevent the connection portion 22-2 from being removed. That is, even when the electronic components 12 and 13 are mounted in the cavity 24, it is possible to provide the wiring board 10A excellent in component mounting property that ensures connection reliability with the connection portion 22-2.

  In the present embodiment, as shown in FIG. 15, the connecting portion 22-2 in which the side surface 30 is inclined has a shape that is narrowed from the surface 54 side to the surface 56 side of the insulating layer 18-2. For this reason, the area of the connection surface 28 is smaller than the area of the exposed surface 26 of the connection part 22-2. Since the connecting portion 22-2 has a narrowed shape, the exposed surface 26 (the connecting surface to be the connection pads P1 and P2) can be enlarged while securing the exposed surface 28 of a desired size. Further, connection reliability with the electronic component 12 that is flip-chip connected can be further ensured.

  Next, a manufacturing method of the wiring board 10A according to the second embodiment of the present invention will be described. First, after preparing the core material 42 (see FIG. 6), as shown in FIG. 16, the connecting portion 22-3 is formed in the through hole 44 formed in the core material 42, and the patterned wiring layer 16 is also formed. -3, 16-4. Subsequently, as shown in FIG. 17, the insulating layer 18-2 provided with the wiring layer 16-2 is laminated on the upper surface of the insulating layer 18-3, and the insulating layer 18-4 provided with the wiring layer 16-5 is provided. Is laminated on the lower surface of the insulating layer 18-3.

  Subsequently, as shown in FIG. 18, through portions 50 and 52 that reach the wiring layer 16-3 from the upper surface side of the insulating layer 18-2 and have an inclined inner wall surface are formed in the insulating layer 18-2. In addition, a penetrating portion 48 that reaches the wiring layer 16-4 from the lower surface side of the insulating layer 18-4 and has an inclined inner wall surface is formed in the insulating layer 18-4. For the formation of the through portions 48, 50, and 52, laser processing with a high degree of freedom in processing shape is used. According to the laser processing, the opening is slightly wide on the laser incident side, and the opening is narrowed so that the bottom is narrowed, so that the through portions 48, 50, and 52 are formed. Thereby, it forms so that the inner wall face of the penetration parts 48, 50, and 52 may incline. Also in the present embodiment, the penetrating portion 50 is formed in a truncated cone-shaped through hole, and the penetrating portion 52 is formed in a quadrangular frustum-shaped through groove.

  Subsequently, as illustrated in FIG. 19, a conductive material is embedded in the through portions 50 and 52 to form a connection portion 22-2 (Filled Via) electrically connected to the wiring layer 16-3. -2 is formed on the upper surface of the insulating layer 18-2 so as to be electrically connected to -2. In addition, a conductive material is embedded in the through portion 48 to form a connection portion 22-4 (Filled Via) that is electrically connected to the wiring layer 16-4, and is electrically connected to the connection portion 22-4. Then, a patterned wiring layer 16-5 is formed on the lower surface of the insulating layer 18-4.

  Subsequently, as shown in FIG. 20, the insulating layer 18-1 provided with the wiring layer 16-1 is laminated on the upper surface of the insulating layer 18-2, and the insulating layer 18-5 provided with the wiring layer 16-6. Is laminated on the lower surface of the insulating layer 18-4. Subsequently, as illustrated in FIG. 21, a connection portion 22-1 that is electrically connected to the wiring layer 16-2 is formed, and the insulating layer 18-is electrically connected to the connection portion 22-1. A patterned wiring layer 16-1 is formed on the upper surface of 1. Further, a wiring portion 22-5 electrically connected to the wiring layer 16-5 is formed, and the wiring patterned on the lower surface of the insulating layer 18-5 so as to be electrically connected to the connection portion 22-5. Layer 16-6 is formed. Next, a surface layer 20U to be the substrate surface (main surface) is laminated on the upper surface of the insulating layer 18-1, and is patterned to have an enlarged opening 36 that is opened larger than the opening of the cavity 24. 20U is formed (see FIG. 15).

  Subsequently, as shown in FIG. 15, the insulating layer 18-1 is penetrated from the surface layer 20 U side, and the middle of the insulating layer 18-2 (that is, the second wiring layer 16-2 and the third wiring layer). Cavity 24 (concave portion) that is recessed to 16-3) is formed. Thus, the exposed surface 26 exposed at the bottom surface of the cavity 24, the connection surface 28 in contact with the wiring layer 16-3, and the side surface 30 intersecting the exposed surface 26 and the connection surface 28 and in contact with the insulating layer 18-2 are provided. A plurality of connection portions 22-2 are formed. Among the plurality of connection portions 22-2, the one formed in the through portion 50 constitutes a connection pad P1 for flip chip connection, and the one formed in the through portion 52 constitutes a connection pad P2 for wire bonding connection. To do. Thereafter, general surface treatment such as oxidation prevention of the connection pads P1 and P2 is performed, and the wiring board 10A is substantially completed.

  With such a manufacturing technique of the wiring board 10A, the same effects as the wiring board 10 can be obtained. That is, a fine wiring pattern can be formed because the wiring structure can withstand counterboring. Further, the manufacturing yield (processing yield) can be improved by providing a wiring structure that can accept the machining accuracy of the counterboring process and the substrate thickness variation.

(Embodiment 3)
A wiring board 10B according to Embodiment 3 of the present invention will be described with reference to FIGS. 22 and 23 are schematic cross-sectional views of the wiring board 10B. This embodiment is different from the cavity 24 of the first embodiment in that the cavity 24 has a shallow recess 24A and a deep recess 24B and is configured in two stages. Below, it demonstrates centering around difference.

  As shown in FIGS. 22 and 23, the wiring board 10B is a multilayer wiring board (six layers of multilayer wiring board) including a plurality of wiring layers 16 to be stacked. The wiring board 10B includes a cavity 24 (concave portion) for mounting electronic components that is recessed from the upper surface side (surface layer 20U side). The cavity 24 has a shallow recess 24A and a deep recess 24B located on the bottom surface (bottom). These shallow recesses 24A and deep recesses 24B can also be formed by counterboring.

  In the present embodiment, the shallow recess 24A is recessed to the middle of the insulating layer 18-2 having the upper surface 54 on which the wiring layer 16-2 is provided and the lower surface 56 on which the wiring layer 16-3 is provided. The bottom surface (bottom portion) of the shallow recess 24A is provided in the insulating layer 18-2. At the bottom surface of the shallow concave portion 24A, the connection portion 22-2 that is electrically connected to the wiring layer 16-3 is exposed. The deep recess 24B is recessed to the middle of the insulating layer 18-4 having the upper surface 17 on which the wiring layer 16-4 is provided and the lower surface 19 on which the wiring layer 16-5 is provided. The bottom face (bottom part) of the deep recessed part 24B is provided in 18-4. Then, the connection portion 22-4 that is electrically connected to the wiring layer 16-5 is exposed on the bottom surface of the deep recess 24B of the wiring substrate 10B shown in FIG.

  In the wiring substrate 10B shown in FIG. 22, the exposed surface 26 of the connection portion 22-2 exposed at the bottom surface of the shallow recess 24A has a rectangular shape as a connection pad P2 for wire bonding connection. As described above, the wiring board 10B shown in FIG. 22 has a structure in which one electronic component is mounted in the deep recess 24B and the electronic component is electrically connected to the connection pad P2 of the shallow recess 24A.

  Further, in the wiring substrate 10B shown in FIG. 23, the exposed surface 26 of the connection portion 22-2 exposed at the bottom surface of the shallow recess 24A has a circular shape as a connection pad P1 for flip chip connection. Further, the exposed surface 26 of the connection portion 22-4 exposed at the bottom surface of the deep recess 24B has a circular shape as a connection pad P1 for flip chip connection. As described above, the wiring substrate 10B shown in FIG. 23 has a structure in which, for example, electronic components are mounted in each of the shallow concave portion 24A and the deep concave portion 24B, and each electronic component is electrically connected to the connection pad P1.

  Further, in the wiring board 10B shown in FIG. 23, the connecting portion 22-2 has a shape that is narrowed from the surface 54 side (the substrate upper surface side) to the surface 56 side (the substrate lower surface side), and the connecting portion 22-4 is the surface 17. The shape widens from the side (substrate upper surface side) to the surface 19 side (substrate lower surface side). According to this, for example, a thin electronic component is mounted in the shallow concave portion 24A, and a deep electronic component is mounted in the deep concave portion 24B, so that the connection portion 22-2 is used corresponding to a plurality of electronic components to be mounted. Thus, it is possible to further secure the connection reliability with the electronic component or to make it difficult to remove the connection portion 22-4. In the wiring board 10B, the case where the cavity 24 is configured by two-stage recesses has been described. However, the configuration is not limited to this, and the case may be configured by a plurality of recesses of three or more stages.

(Embodiment 4)
A wiring board 10C according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 24 is a schematic cross-sectional view of the wiring board 10C. This embodiment is different from the cavity 24 of the first embodiment in that a through portion 58 that penetrates the insulating layers 18-4 and 18-5 is provided on the bottom surface of the cavity 24. Below, it demonstrates centering around difference.

  As shown in FIG. 24, the wiring board 10C is a multilayer wiring board (six layers of multilayer wiring board) including a plurality of wiring layers 16 to be stacked. This wiring board 10C includes a cavity 24 (recessed portion) for mounting electronic components that is recessed from the upper surface side (surface layer 20U side). And this cavity 24 is provided with the penetration part 58 formed in the bottom face (bottom part) of the cavity 24, for example by the drilling after a counterbore process. In such a wiring substrate 10 </ b> C, for example, a heat dissipation plate can be attached to the surface layer 20 </ b> L serving as the lower surface of the substrate, and an electronic component can be mounted on the through portion 58, thereby improving heat dissipation. Further, in the wiring substrate 10B, the electronic component can be electrically connected to the connection pad P2 for wire bonding connection formed in the cavity 24 around the opening of the through portion 58.

(Embodiment 5)
A wiring board 10D according to Embodiment 5 of the present invention will be described with reference to FIG. FIG. 25 is a schematic cross-sectional view of the wiring board 10D. This embodiment is different from the first embodiment in that two cavities 24 that are recessed from the upper and lower surfaces of the substrate are provided. Below, it demonstrates centering around difference.

  As shown in FIG. 25, the wiring board 10D is a multilayer wiring board (six layers of multilayer wiring board) including a plurality of wiring layers 16 to be stacked. The wiring board 10D includes an electronic component mounting cavity 24 (recessed portion) recessed from the upper surface side (surface layer 20U side) and an electronic component mounting cavity 24 (recessed portion) recessed from the lower surface side (surface layer 20L side). Are opened in one direction and the opposite direction of the substrate thickness. According to this, a plurality of electronic components can be mounted according to the usage situation.

(Embodiment 6)
A wiring board 10E according to Embodiment 6 of the present invention will be described with reference to FIG. FIG. 26 is a schematic cross-sectional view of the wiring board 10E. This embodiment is different from the six-layer wiring board 10 of the first embodiment in that it is a two-layer wiring board 10E. Below, it demonstrates centering around difference.

  As shown in FIG. 26, the wiring board 10E is a multilayer wiring board (two-layer multilayer wiring board) including a plurality of wiring layers 16 to be stacked. This wiring board 10E includes a cavity 24 (concave portion) for mounting electronic components that is recessed from the upper surface side (surface layer 20U side). Even if it is such a two-layer wiring board 10E or a three-layer or more wiring board, the same effect as the wiring board 10 can be obtained.

  Although the present invention has been specifically described above based on the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. That is, the wiring board according to the embodiment is a part of the wiring board according to the present invention, and the effectiveness of the present invention is not changed even in a structure in which the embodiments are combined.

10 Wiring board; 12, 13 Electronic component; 14 Electronic product;
16 wiring layers; 17 surfaces; 18 insulating layers;
19 surfaces; 20 surface layers; 22 connecting parts;
24 cavity (recess); 26 exposed surface; 28 connecting surface;
30 side surfaces; 32 connection bumps;
34 Bonding wire; 36 Enlarged opening; 38 Stepped portion;
40 sealing resin; 42 core material; 44 through hole;
46 insulating material; 48, 50, 52 through; 54, 56 surfaces;
58 penetration part; 500 wiring board;
P1, P2 connection pads.

Claims (17)

A plurality of laminated wiring layers;
An insulating layer having first and second surfaces on which the first and second wiring layers of the plurality of wiring layers are respectively provided;
A recess recessed from the first surface side to the middle of the insulating layer;
A connection portion provided in the insulating layer so as to be electrically connected to the second wiring layer and exposed at the bottom surface of the recess;
The connection portion has an exposed surface exposed at a bottom surface of the recess, a connection surface in contact with the second wiring layer, and a side surface that intersects the exposed surface and the connection surface and contacts the insulating layer, A wiring board characterized in that a side surface is inclined. The wiring board according to claim 1,
The connecting portion has a shape that spreads from the first surface side to the second surface side. The wiring board according to claim 1,
The connecting portion has a shape that narrows from the first surface side to the second surface side. In the wiring board as described in any one of Claims 1-3,
The connecting portion is provided in the insulating layer between the first wiring layer and the second wiring layer by electrically connecting the first wiring layer and the second wiring layer;
The first surface side end portion of the connection portion has the other portion of the first surface side end portion scraped off by the recess while a part of the first surface side end portion is in contact with the first wiring layer. An exposed surface is provided. In the wiring board as described in any one of Claims 1-4,
The exposed surface has a rectangular shape in which the direction from the center of the bottom surface of the concave portion to the outer peripheral portion of the bottom surface is a longitudinal direction. The wiring board according to claim 5,
A plurality of the connection portions are provided along the bottom edge of the recess. In the wiring board as described in any one of Claims 1-6,
A surface layer provided on the surface of the substrate so as to expose the recess and cover the first wiring layer;
The surface layer has an enlarged opening that is larger than the opening of the recess. In the wiring board as described in any one of Claims 1-7,
A through portion penetrating the insulating layer is provided at the bottom surface of the concave portion. In the wiring board according to claim 1,
The insulating layer is a first insulating layer, the concave portion is a first concave portion, and the connecting portion is a first connecting portion,
A second insulating layer having third and fourth surfaces provided with third and fourth wiring layers of the plurality of wiring layers, respectively;
A second recess recessed from the third surface side to the middle of the second insulating layer;
A second connection portion provided in the second insulating layer so as to be electrically connected to the fourth wiring layer and exposed at a bottom surface of the second recess;
The first, second, third, and fourth wiring layers are stacked in this order,
The second connection portion is an exposed surface exposed at the bottom surface of the second recess, a connection surface in contact with the third wiring layer, a side surface that intersects the exposed surface and the connection surface, and is in contact with the second insulating layer. And
A side surface of the second connecting portion is inclined;
When the first connection portion has a shape that widens from the first surface side to the second surface side, the second connection portion has a shape that narrows from the third surface side to the fourth surface side. ,
When the first connection portion has a shape that narrows from the first surface side to the second surface side, the second connection portion has a shape that spreads from the third surface side to the fourth surface side. . The wiring board according to claim 9, wherein
The first recess opens in one direction of the substrate thickness;
The second recess opens in a direction opposite to the one direction. A method of manufacturing a wiring board comprising: a plurality of wiring layers to be laminated; and an insulating layer having first and second surfaces on which first and second wiring layers of the plurality of wiring layers are respectively provided.
(A) a step of forming, in the insulating layer, a penetrating portion that reaches the first wiring layer from the second surface side and whose inner wall surface is inclined;
(B) embedding a conductive material in the penetrating portion to form a connecting portion electrically connected to the first wiring layer;
(C) forming the second wiring layer on the second surface so as to be electrically connected to the connection portion;
(D) By forming a recess that is recessed from the first surface side to the middle of the insulating layer, an exposed surface that is exposed at the bottom surface of the recess, a connection surface that is in contact with the second wiring layer, the exposed surface, and A step of forming the connection portion having a side surface that intersects the connection surface and contacts the insulating layer, and has a shape that widens from the first surface side to the second surface side; A method for manufacturing a wiring board, comprising: A method of manufacturing a wiring board comprising: a plurality of wiring layers to be laminated; and an insulating layer having first and second surfaces on which first and second wiring layers of the plurality of wiring layers are respectively provided.
(A) a step of forming, in the insulating layer, a penetrating portion that reaches the second wiring layer from the first surface side and whose inner wall surface is inclined;
(B) embedding a conductive material in the penetrating portion to form a connecting portion that is electrically connected to the second wiring layer;
(C) forming the first wiring layer on the first surface so as to be electrically connected to the connection portion;
(D) By forming a recess that is recessed from the first surface side to the middle of the insulating layer, an exposed surface that is exposed at the bottom surface of the recess, a connection surface that is in contact with the second wiring layer, the exposed surface, and The connecting portion has a side surface that intersects with the connection surface and contacts the insulating layer, and has a shape that is narrowed from the first surface side to the second surface side, and the side surface is inclined. A method for manufacturing a wiring board comprising the steps of: In the manufacturing method of the wiring board of Claim 11 or 12,
In the step (d), by forming the recess, a part of the first surface side end of the connection portion is kept in contact with the first wiring layer, and the other portion of the first surface side end is changed. The exposed surface is formed by shaving. In the manufacturing method of the wiring board as described in any one of Claims 11-13,
Before the step (d), a surface layer having an enlarged opening that is larger than the opening of the recess and provided on the substrate surface so as to cover the first wiring layer is formed. In the manufacturing method of the wiring board as described in any one of Claims 11-14,
After the step (d), a penetrating portion that penetrates the insulating layer is formed on the bottom surface of the concave portion. In the manufacturing method of the wiring board as described in any one of Claims 11-15,
In the step (d), the recess is formed by counterboring. In the manufacturing method of the wiring board as described in any one of Claims 11-16,
In the step (a), the through portion is formed by laser processing.

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