Wiring circuit board and method for manufacturing wiring circuit board

Abstract

To provide: a wiring circuit board which suppresses peeling at an external connection terminal and suppresses deterioration in connection reliability; a method for manufacturing the same; a semiconductor package; and an electronic apparatus.SOLUTION: A wiring circuit board includes a first insulating layer 1, a first conductor layer 2, a second insulating layer 7 located on the first insulating layer on a side opposite to the first conductor layer side, a second conductor layer 8 disposed on the second insulating layer, a third insulating layer 9 disposed on the second conductor layer and having an opening 9a, and an interlayer connection 6 electrically connecting the first conductor layer and the second conductor layer. The opening 9a is formed on an extension line of the interlayer connection 6 in a thickness direction of the wiring circuit board. The second conductor layer exposed through the opening and the interlayer connection in contact with the second conductor layer constitute an external terminal. The second conductor layer and the interlayer connection are in contact with each other on a surface of the interlayer connection in the thickness direction of the wiring circuit board, and the second conductor layer and the interlayer connection are also in contact with each other at a part of a side face of the interlayer connection when the surface is a top surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wiring circuit board, a method for manufacturing a wiring circuit board, a semiconductor package including the wiring circuit board, and an electronic device.

Background Art

[0002] A wiring circuit board is manufactured by laminating a conductor portion such as wiring and various insulating layers on a base material. The conductor portion and the insulating layer are patterned, for example, by a photolithography method.

[0003] As a wiring circuit board, for example, there is an inter-board connection structure between a flexible board having connection pads connected to a wiring pattern formed on its surface and a rigid board having connection pads connected to the wiring pattern formed on its surface. A through hole penetrating the flexible board and its connection pad is formed. With the connection pads on the surface of the flexible board facing upward, the flexible board is placed on the surface of the rigid board, and the connection pads of the flexible board and the connection pads of the rigid board are connected by solder through the through hole. An inter-board connection structure characterized by this has been proposed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The wiring circuit board and the semiconductor chip placed and connected thereon have different coefficients of thermal expansion. Therefore, the wiring circuit board warps. As a result, delamination may occur at the external connection terminals of the wiring circuit board, and the connection reliability may decrease.

[0006] An object of the present invention is to provide a circuit connection board that suppresses peeling at an external connection terminal and suppresses a decrease in connection reliability, a semiconductor package including the wiring circuit board, and an electronic device.

Means for Solving the Problems

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved and have completed the present invention having the following gist. That is, the present invention includes the following.

[0008] [1] A first insulating layer, A first conductor layer disposed on the first insulating layer, A second insulating layer located on the side of the first insulating layer opposite to the first conductor layer side, A second conductor layer disposed on the second insulating layer, A third insulating layer disposed on the second conductor layer and having an opening, An interlayer connection portion that electrically connects the first conductor layer and the second conductor layer, A wiring circuit board having: The opening is formed on an extension line of the interlayer connection portion in the thickness direction of the wiring circuit board, The second conductor layer exposed by the opening and the interlayer connection portion in contact with the second conductor layer constitute an external connection terminal, The second conductor layer and the interlayer connection portion are in contact with each other on a surface of the interlayer connection portion in the thickness direction of the wiring circuit board, and the second conductor layer and the interlayer connection portion are also in contact with each other at a part of a side surface of the interlayer connection portion when the surface is the upper surface, Wiring circuit board. [2] The wiring circuit board according to [1], wherein the second conductor layer has wiring. [3] The wiring circuit board according to [1] or [2], wherein a cross-sectional shape of the interlayer connection portion is rectangular in a cross-section parallel to the thickness direction of the wiring circuit board. [4] The wiring circuit board according to any one of [1] to [3], wherein a cross-sectional shape of the interlayer connection portion is a trapezoid having a first base on the second conductor layer side and a second base on the first conductor layer side shorter than the first base in a cross-section parallel to the thickness direction of the wiring circuit board. [5] The wiring circuit board according to any one of [1] to [4], wherein the second conductor layer and the interlayer connection portion are in contact with each other on all surfaces in the thickness direction of the wiring circuit board of the interlayer connection portion, and the second conductor layer and the interlayer connection portion are also in contact with each other at a part of a side surface of the interlayer connection portion when the surface is an upper surface and at a portion surrounding the side surface. [6] Further comprising a metal core layer having a through hole, wherein the metal core layer is disposed between the first insulating layer and the second insulating layer, and the interlayer connection portion penetrates through the through hole of the metal core layer. The wiring circuit board according to any one of [1] to [5]. [7] The wiring circuit board according to any one of [1] to [6], wherein the interlayer connection portion has a first interlayer connection portion and a second interlayer connection portion arranged in the thickness direction of the wiring circuit board. [8] A semiconductor package including the wiring circuit board according to any one of [1] to [7]. [9] An electronic device including the semiconductor package according to [8].

[10] A method for manufacturing a wiring circuit board, which manufactures the wiring circuit board according to any one of [1] to [7], the method including: forming a second insulating layer precursor so as to cover the interlayer connection portion; forming the second insulating layer by thinning the second insulating layer precursor so that the interlayer connection portion protrudes from and is exposed from the second insulating layer precursor; forming a second conductor layer on the second insulating layer and the interlayer connection portion. The method for manufacturing a wiring circuit board includes the above steps.

[11] The method for manufacturing a wiring circuit board according to

[10] , further including forming a third insulating layer having an opening so that an external connection terminal formed by the second conductor layer and the interlayer connection portion in contact with the second conductor layer is exposed through the opening.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a circuit connection board that suppresses peeling at an external connection terminal and suppresses a decrease in connection reliability, a semiconductor package including the wiring circuit board, and an electronic device.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 2E

Figure 2F

Figure 2G

Figure 2H

Figure 2I

Figure 2J

Figure 2K

Figure 2L

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 6E

Figure 6F

Figure 6G

[0011] (Wiring Circuit Board and Method for Manufacturing Wiring Circuit Board) The wiring circuit board of the present invention includes a first insulating layer, a first conductor layer, a second insulating layer, a second conductor layer, a third insulating layer, and an interlayer connection portion. The first conductor layer is disposed on the first insulating layer. The second insulating layer is located on the side opposite to the first conductor layer side of the first insulating layer. The second conductor layer is disposed on the second insulating layer. The third insulating layer is disposed on the second conductor layer. The third insulating layer has an opening. The interlayer connection portion electrically connects the first conductor layer and the second conductor layer. The opening is formed on the extension line of the interlayer connection portion in the thickness direction of the wiring circuit board. The second conductor layer exposed by the opening and the interlayer connection portion in contact with the second conductor layer constitute an external connection terminal. The second conductor layer and the interlayer connection portion are in contact with each other on the surface in the thickness direction of the wiring circuit board in the interlayer connection portion, and the second conductor layer and the interlayer connection portion are also in contact with each other at a part of the side surface of the interlayer connection portion when the above surface is the upper surface.

[0012] In the wiring circuit board of the present invention, in addition to the second conductor layer and the interlayer connection portion being in contact with each other on the surface in the thickness direction of the wiring circuit board in the interlayer connection portion, the second conductor layer and the interlayer connection portion are also in contact with each other at a part of the side surface of the interlayer connection portion when the above surface is the upper surface. By doing so, the connection between the second conductor layer and the interlayer connection portion becomes strong, and even when the wiring circuit board warps, delamination of the external connection terminal is less likely to occur.

[0013] Hereinafter, an example of the wiring circuit board of the present invention will be described with reference to FIG. 1. The wiring circuit board shown in FIG. 1 includes a first insulating layer 1, a first conductor layer 2, a second insulating layer 7, a second conductor layer 8, a third insulating layer 9, and an interlayer connection portion 6. The first conductor layer 2 is disposed on the first insulating layer 1. The second insulating layer 7 is located on the side opposite to the first conductor layer 2 side of the first insulating layer 1. The second conductor layer 8 is disposed on the second insulating layer 7. The third insulating layer 9 is disposed on the second conductor layer 8. The third insulating layer 9 has an opening 9a. The interlayer connection portion 6 electrically connects the first conductor layer 2 and the second conductor layer 8. The opening 9a is formed on the extension line of the interlayer connection portion 6 in the thickness direction of the wiring circuit board. The second conductor layer (a part 8a of the second conductor layer) exposed by the opening 9a and the interlayer connection portion 6 in contact with the second conductor layer (a part 8a of the second conductor layer) constitute an external connection terminal. The second conductor layer (a part 8a of the second conductor layer) and the interlayer connection portion 6 are in contact with each other on the surface of the interlayer connection portion 6 in the thickness direction of the wiring circuit board, and also in contact with each other at a part of the side surface of the interlayer connection portion 6 when the said surface is taken as the upper surface. In the thickness direction of the wiring circuit board, the surface (upper surface) of the interlayer connection portion 6 in contact with the second conductor layer 8 is on the side opposite to the first insulating layer 1 side rather than the side of the second insulating layer 7 on the second conductor layer 8 side. In other words, the interlayer connection portion 6 protrudes from the second insulating layer 8. The side surface of the interlayer connection portion 6 in contact with the second conductor layer (a part 8a of the second conductor layer) is the side surface of a part of the interlayer connection portion 6 that protrudes from the second insulating layer 7. The wiring circuit board shown in FIG. 1 further has a metal core layer 10, a fourth insulating layer 3, a third conductor layer 4, and a fifth insulating layer 5. The metal core layer 10 has a through hole. The metal core layer 10 is disposed between the first insulating layer 1 and the second insulating layer 7. The interlayer connection portion 6 penetrates through the through hole of the metal core layer 10. The fifth insulating layer 5 has an opening 5a. The opening 5a is formed on the extension line of the interlayer connection portion 6 in the thickness direction of the wiring circuit board.

[0014] The first conductor layer 2, the second conductor layer 8, and the third conductor layer 4 may each have wiring. When a conductor layer has wiring, the conductor layer can be referred to as a wiring layer.

[0015] The metal core layer is, for example, an element for ensuring the rigidity of the wiring circuit board. The material of the metal core layer is not particularly limited, and examples thereof include Cu, Cu alloys, Al, stainless steel, FeNi alloys such as 42 alloy, and combinations thereof. Among these, from the viewpoints of thermal conductivity and electrical conductivity, Cu and Cu alloys are preferable. Also, from the viewpoint of suppressing warpage, stainless steel and 42 alloy are preferable, and 42 alloy is more preferable. The thickness of the metal core layer is not particularly limited. For example, it is 10 μm or more, preferably 15 μm or more, and for example, it is 500 μm or less, preferably 300 μm or less. In the present invention, "thickness" means the length in the thickness direction of the wiring circuit board and the metal core layer. The thickness direction of the wiring circuit board and the metal core layer refers to, for example, a direction orthogonal to the plane direction of the metal core layer.

[0016] When the metal core layer has a through hole, the shape of the through hole in the metal core layer is not particularly limited. In the present invention, the tapered shape means a shape in which one opening of the through hole is larger than the other opening. Therefore, when the through hole has a tapered shape, in a cross section parallel to the thickness direction of the metal core layer, the shape of the side surface of the through hole is, for example, a trapezoid.

[0017] When the metal core layer has a through hole, the shape of the side surface of the through hole in the metal core layer is not particularly limited. The shape of the side surface of the through hole in the metal core layer may be arcuate or linear in a cross section parallel to the thickness direction of the metal core layer. The arcuate shape here means a shape that is recessed from the through hole side toward the metal core layer side. When the shape is arcuate, there is an insulating portion between the metal core layer and a conductor (for example, an interlayer connection portion) in the through hole, and the adhesion between the metal core layer and the conductor can be enhanced. When the shape is linear, it becomes easier to form a seed layer when forming an interlayer connection portion during the manufacture of the wiring circuit board.

[0018] The material of the insulating layer (e.g., the first insulating layer, the second insulating layer, the third insulating layer, the fourth insulating layer, the fifth insulating layer) in the wiring circuit board is not particularly limited, and examples thereof include synthetic resins. Examples of the synthetic resin include polyimide, polyamideimide, polyether nitrile, polyether sulfone, polyethylene terephthalate, polyethylene naphthalate, polyvinyl chloride, epoxy resin, phenol resin, acrylic resin, liquid crystal polymer, and the like. Preferably, it is polyimide. For example, the insulating layer is formed using photosensitive polyimide. The insulating layer may contain particles (fillers). Examples of the particles include inorganic particles and organic particles. Inorganic particles are preferred as the particles. Examples of the inorganic particles include particles containing silica such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, crystalline silica, and amorphous silica. Further, examples of the material of the inorganic particles include simple metals such as aluminum, gold, silver, copper, and nickel, and alloys. Particles such as aluminum borate whiskers, amorphous carbon black, and graphite may also be used. The shape of the particles may be various shapes such as spherical, needle-like, and flake-like. As the particles, only one of the above or two or more thereof may be employed. The resin used for forming the insulating layer may be a thermosetting resin or a thermoplastic resin. Further, the resin used for forming the insulating layer may be a photosensitive resin or a non-photosensitive resin. The insulating layer can be formed, for example, by the following method. (I): Laminating and thermally pressing a thermosetting insulating resin film (e.g., a B-stage insulating resin film) (II): Coating and drying a liquid resin composition When the insulating layer has an opening, examples of the method for forming the opening in the insulating layer include the following methods. (III): When the insulating layer is formed using a thermosetting resin or a thermoplastic resin, laser irradiation (IV): When forming the insulating layer using a photosensitive resin, selective exposure and development of the photosensitive resin film The thickness of the insulating layer is not particularly limited. For example, it is 1 μm or more, preferably 3 μm or more, and for example, 35 μm or less, preferably 20 μm or less.

[0019] Examples of the material of the conductor layer (for example, the first conductor layer, the second conductor layer, the third conductor layer) in the wiring circuit board include metal materials. Examples of the metal materials include copper, nickel, gold, solder, and their alloys. The thickness of the conductor layer is not particularly limited. For example, it is 3 μm or more, preferably 5 μm or more, and for example, 50 μm or less, preferably 30 μm or less. Since the connection layer is a part of the conductor layer, the material of the connection layer is the same as that of the conductor layer. The thickness of the connection layer is, for example, the same as that of the conductor layer. However, when the connection layer is on the interlayer connection portion, the thickness of the connection layer may be thicker than that of other parts (for example, wiring) of the conductor layer.

[0020] The main component of the interlayer connection portion is not particularly limited. For example, metal materials are included. Examples of the metal materials include copper, nickel, gold, silver, solder, and their alloys. The shape of the interlayer connection portion is not particularly limited. The cross-sectional shape of the interlayer connection portion is not particularly limited. For example, in a cross-section parallel to the thickness direction of the wiring circuit board, it may be rectangular or trapezoidal.

[0021] The interlayer connection portion may be composed of two or more parts. The two or more parts are arranged, for example, in the thickness direction of the wiring circuit board to form the interlayer connection portion. When the interlayer connection portion is composed of two or more parts, they may be the same material or different materials. Here, different materials include, for example, different types of main components, or the same type of main component but at least one of the types and contents of the sub-components is different. The interlayer connection part has, for example, a first interlayer connection part and a second interlayer connection part. The first interlayer connection part and the second interlayer connection part are arranged side by side in the thickness direction of the wiring circuit board to form the interlayer connection part. The first interlayer connection part is in contact with, for example, the first conductor layer. The second interlayer connection part is in contact with, for example, the second conductor layer. In this case, the second conductor layer and the second interlayer connection part are in contact with each other on the surface in the thickness direction of the wiring circuit board in the second interlayer connection part, and the second conductor layer and the second interlayer connection part are also in contact with each other at a part of the side surface of the second interlayer connection part when the above surface is the upper surface. Examples of the combination of the shape of the cross section of the first interlayer connection part and the shape of the cross section of the second interlayer connection part include the following combinations. · A combination in which the shape of the cross section of the first interlayer connection part is a trapezoid with the second conductor layer side as the first base and the first conductor layer side as the second base shorter than the first base in a cross section parallel to the thickness direction of the wiring circuit board, and the shape of the cross section of the second interlayer connection part is a rectangle in a cross section parallel to the thickness direction of the wiring circuit board. · A combination in which the shape of the cross section of the first interlayer connection part is a rectangle in a cross section parallel to the thickness direction of the wiring circuit board, and the shape of the cross section of the second interlayer connection part is a trapezoid with the second conductor layer side as the first base and the first conductor layer side as the second base shorter than the first base in a cross section parallel to the thickness direction of the wiring circuit board.

[0022] When there is an interlayer connection part in the through hole in the metal core layer, the number of interlayer connection parts arranged in one through hole may be one or two or more. In this case, two or more interlayer connection parts are arranged side by side in the plane direction of the metal core layer in the through hole and are arranged side by side via an insulating part in the through hole. On the other hand, two or more interlayer connection parts are each electrically connected to the first conductor layer and the second conductor layer. Therefore, two or more interlayer connection parts can also be regarded as constituting one interlayer connection part integrally.

[0023] In a wiring circuit board, in addition to the second conductor layer and the interlayer connection portion being in contact with each other on all surfaces in the thickness direction of the wiring circuit board at the interlayer connection portion, it is preferable that the second conductor layer and the interlayer connection portion are also in contact with each other at a part of the side surface of the interlayer connection portion when the surface is defined as the upper surface, which is a part that goes around the side surface. By doing so, the connection between the second conductor layer and the interlayer connection portion becomes stronger, and even when the wiring circuit board warps, delamination of the external connection terminals is less likely to occur.

[0024] For example, in the thickness direction of the wiring circuit board, the surface (upper surface) of the interlayer connection portion in contact with the second conductor layer is on the side opposite to the first insulating layer side rather than the surface of the second insulating layer on the second conductor layer side. In other words, the interlayer connection portion protrudes from the second insulating layer. In this case, the side surface of the interlayer connection portion in contact with the second conductor layer (a part of the second conductor layer) is the side surface of a part of the interlayer connection portion that protrudes from the second insulating layer. The thickness of a part of the interlayer connection portion that protrudes from the second insulating layer is not particularly limited, but from the viewpoint of preventing the exposure of the interlayer connection portion from the third insulating layer and strengthening the connection between the interlayer connection portion and the second conductor layer, it is preferably one to three times the thickness of the second conductor layer, and more preferably one to two times. Here, the thickness of the second conductor layer refers to, for example, the height of the wiring when the second conductor layer has a wiring. Also, the thickness of the second conductor layer refers to, for example, the thickness at the portion of the second conductor layer in contact with the surface in the thickness direction of the wiring circuit board at the interlayer connection portion. That is, the thickness of the second conductor layer does not refer to the thickness of the stepped portion (a portion that is relatively thicker than other portions) of the second conductor layer formed in contact with the interlayer connection portion.

[0025] The wiring circuit board may have a seed layer (not shown). The seed layer is used as a conductive layer for electrolytic plating. Examples of the material of the seed layer include copper, chromium, titanium, nickel, tungsten, and alloys thereof. Also, the seed layer may be a single layer or a multilayer. In the case of a multilayer, examples of the material of each layer include copper, chromium, titanium, nickel, tungsten, and alloys thereof.

[0026] The manufacturing method of the wiring circuit board of the present invention includes the following steps. · A step of forming a second insulating layer precursor so as to cover the interlayer connection part · A step of thinning the second insulating layer precursor to form a second insulating layer so that the interlayer connection part protrudes from the second insulating layer precursor and is exposed · A step of forming a second conductor layer on the second insulating layer and the interlayer connection part The manufacturing method of the wiring circuit board of the present invention is a method for manufacturing the wiring circuit board of the present invention.

[0027] The manufacturing method of the wiring circuit board may further include a step of forming a third insulating layer having an opening so that an external connection terminal formed by the second conductor layer and the interlayer connection part in contact with the second conductor layer is exposed through the opening.

[0028] An embodiment of the manufacturing method of the wiring circuit board shown in FIG. 1 will be described with reference to FIGS. 2A to 2L. First, a metal core layer 10 is prepared (FIG. 2A). Next, a first insulating layer 1 having an opening 1a is formed on one surface of the metal core layer 10 (FIG. 2B). The formation of the first insulating layer 1 having the opening 1a can be performed, for example, as follows. · Laminating a B-stage insulating resin film and thermocompression bonding · Forming the opening 1a by laser irradiation or the like on the insulating layer

[0029] Next, a patterned first conductor layer 2 is formed on the first insulating layer 1 (FIG. 2C). As shown in FIG. 2C, a part of the first conductor layer 2 fills the opening 1a. The formation of the first conductor layer 2 can be performed, for example, as follows. · Forming a seed layer (not shown) on the first insulating layer 1 · Forming a photoresist film (not shown) on the seed layer · Forming a resist pattern by selective exposure and development of the photoresist film (partial exposure of the seed layer) · Electrolytic plating on the exposed seed layer · Removal of the photoresist film and removal of the unnecessary seed layer The formed patterned electrolytic plating layer becomes the first conductor layer 2.

[0030] Next, a fourth insulating layer 3 having an opening 3a is formed so as to cover the first conductor layer 2 and expose a part of the first conductor layer 2 (FIG. 2D). The formation of the fifth insulating layer 5 having the opening 3a can be performed, for example, as follows. · Lamination of a B-stage insulating resin film and thermal pressing · Formation of the opening 3a by laser irradiation or the like on the insulating layer

[0031] Next, a patterned third conductor layer 4 is formed on the fourth insulating layer 3 (FIG. 2E). The formation of the third conductor layer 4 can be performed, for example, as follows. · Formation of a seed layer (not shown) on the fourth insulating layer 3 · Formation of a photoresist film (not shown) on the seed layer · Formation of a resist pattern by selective exposure and development of the photoresist film (partial exposure of the seed layer) · Electrolytic plating on the exposed seed layer · Removal of the photoresist film and removal of the unnecessary seed layer The formed patterned electrolytic plating layer becomes the third conductor layer 4. A part of the third conductor layer 4 fills the opening 3a and is electrically connected to the first conductor layer 2.

[0032] Next, a fifth insulating layer 5 having an opening 5a is formed so as to cover the third conductor layer 4 and expose a part of the third conductor layer 4 (FIG. 2F). The formation of the fourth insulating layer 3 having the opening 5a can be performed, for example, as follows. · Lamination of a B-stage insulating resin film and thermal pressing · Formation of the opening 5a by laser irradiation or the like on the insulating layer

[0033] Next, a through hole 10a is formed at a predetermined position of the metal core layer 10 (FIG. 2G). The through hole 10a can be formed, for example, as follows. The predetermined position is a position in the thickness direction where a part of the first conductor layer 2 that fills the opening 1a exists. · Formation of a photoresist film (not shown) on the metal core layer 10 · Formation of a resist pattern by selective exposure and development of the photoresist film (partial exposure of the metal core layer 10) · Wet etching of the exposed metal core layer 10 (for example, wet etching using ferric chloride) · Removal of the photoresist film Through the above steps, the through hole 10a is formed.

[0034] Next, an interlayer connection portion 6 is formed in the through hole 10a so as not to contact the metal core layer 10 and to contact the first conductor layer 2 (FIG. 2H). The interlayer connection portion 6 can be formed, for example, as follows. · Formation of a photoresist film (not shown) on the metal core layer 10 · Formation of a resist pattern by selective exposure and development of the photoresist film (exposure of the first conductor layer 2 through the through hole 10a) · Plating on the exposed first conductor layer 2 · Removal of the photoresist film At this time, plating is performed so that the thickness (height) of the interlayer connection portion 6 is greater than the thickness of the metal core layer 10. By doing so, the interlayer connection portion 6 protrudes from the surface of the metal core layer 10. Through the above steps, the interlayer connection portion 6 is formed. Note that the cross-sectional shape of the interlayer connection portion 6 is rectangular in a cross-section parallel to the thickness direction of the wiring circuit board.

[0035] Next, a second insulating layer precursor 7a is formed on the metal core layer 10 so as to cover the interlayer connection portion 6 (FIG. 2I). The second insulating layer precursor 7a is in a layer form. The second insulating layer precursor 7a can be formed, for example, by laminating a B-stage insulating resin film and forming an insulating layer by thermal pressing.

[0036] Next, the second insulating layer precursor 7a is thinned to form the second insulating layer 7 so that the interlayer connection portion 6 protrudes from the second insulating layer precursor 7a and is exposed (FIG. 2J). Examples of the method for thinning the second insulating layer precursor 7a include etching.

[0037] Next, a patterned second conductor layer 8 is formed on the second insulating layer 7 and the interlayer connection portion 6 (FIG. 2K). The second conductor layer 8 can be formed, for example, as follows. · Formation of a seed layer (not shown) on the second insulating layer 7 and the interlayer connection portion 6 · Formation of a photoresist film (not shown) on the seed layer · Formation of a resist pattern by selective exposure and development of the photoresist film (partial exposure of the seed layer) · Electrolytic plating on the exposed seed layer · Removal of the photoresist film and removal of the unnecessary seed layer The formed patterned electrolytic plating layer becomes the second conductor layer 8. As described above, the second conductor layer 8 is formed. At this time, a part 8a of the second conductor layer and the interlayer connection portion 6 in contact with the part 8a of the second conductor layer serve as external connection terminals. And by forming a part 8a of the second conductor layer so as to cover the interlayer connection portion 6, a part 8a of the second conductor layer and the interlayer connection portion 6 are in contact with each other on the surface in the thickness direction of the wiring circuit board at the interlayer connection portion 6, and a part 8a of the second conductor layer and the interlayer connection portion 6 are also in contact with each other on a part of the side surface of the interlayer connection portion 6 when the above surface is the upper surface.

[0038] Next, a third insulating layer 9 having an opening 9a is formed so as to cover the second conductor layer 8 and expose the external connection terminal (FIG. 2L). The third insulating layer 9 having the opening 9a can be formed, for example, as follows. · Laminating a B-stage insulating resin film and thermocompression bonding · Forming the opening 9a by laser irradiation or the like on the insulating layer As described above, the wiring circuit board shown in FIG. 1 (FIG. 2L) is obtained.

[0039] FIG. 3 is a schematic diagram of another embodiment of the wiring circuit board. In FIG. 3, a part of the first conductor layer 2 and the interlayer connection portion 6 are in contact with each other on the surface in the thickness direction of the wiring circuit board at the interlayer connection portion 6, and a part of the side surface of the interlayer connection portion 6 when the above surface is the upper surface is also in contact with a part of the first conductor layer 2 and the interlayer connection portion 6. By doing so, the connection between the first conductor layer 2 and the interlayer connection portion 6 becomes strong, and even when the wiring circuit board warps, delamination between the first conductor layer 2 and the interlayer connection portion 6 at the contact surface is less likely to occur. The other structure of the wiring circuit board in FIG. 3 is the same as the structure of the wiring circuit board shown in FIG. 1.

[0040] FIG. 4 is a schematic diagram of another embodiment of the wiring circuit board. In FIG. 4, the interlayer connection portion 6 is composed of a first interlayer connection portion 6a and a second interlayer connection portion 6b. The first interlayer connection portion 6a is in contact with the first conductor layer 2. The second interlayer connection portion 6b is in contact with the second conductor layer 8. The cross-sectional shape of the first interlayer connection portion 6a is a trapezoid with the side of the second conductor layer 8 as the first base and the side of the first conductor layer 2 as the second base shorter than the first base in a cross-section parallel to the thickness direction of the wiring circuit board. The cross-sectional shape of the second interlayer connection portion 6b is a rectangle in a cross-section parallel to the thickness direction of the wiring circuit board. The other structure of the wiring circuit board in FIG. 4 is the same as the structure of the wiring circuit board shown in FIG. 1. In the wiring circuit board of FIG. 4, the second conductor layer 8 and the second interlayer connection portion 6b are in contact with each other on the surface in the thickness direction of the wiring circuit board at the second interlayer connection portion 6b, and a part of the side surface of the second interlayer connection portion 6b when the above surface is the upper surface is also in contact with the second conductor layer 8 and the second interlayer connection portion 6b. As in the wiring circuit board of FIG. 4, the interlayer connection portion 6 is composed of the first interlayer connection portion 6a and the second interlayer connection portion 6b. In other words, by forming the interlayer connection portion 6 in two steps, it is possible to form the interlayer connection portion 6 while avoiding via filling, which is technically difficult to perform, in which the interlayer connection portion 6 is formed at once.

[0041] FIG. 5 is a schematic diagram of another embodiment of the wiring circuit board. In FIG. 5, the interlayer connection portion 6 is composed of a first interlayer connection portion 6c and a second interlayer connection portion 6d. The first interlayer connection portion 6c is in contact with the first conductor layer 2. The second interlayer connection portion 6d is in contact with the second conductor layer 8. The shape of the cross section of the first interlayer connection portion 6c is rectangular in a cross section parallel to the thickness direction of the wiring circuit board. The shape of the cross section of the second interlayer connection portion 6d is a trapezoid having the side of the second conductor layer 8 as the first base and the side of the first conductor layer 2 as the second base shorter than the first base in a cross section parallel to the thickness direction of the wiring circuit board. Other structures of the wiring circuit board in FIG. 5 are the same as those of the wiring circuit board shown in FIG. 1. In the wiring circuit board of FIG. 5, the second conductor layer 8 and the second interlayer connection portion 6d are in contact with each other on the surface in the thickness direction of the wiring circuit board in the second interlayer connection portion 6d, and the second conductor layer 8 and the second interlayer connection portion 6d are also in contact with each other at a part of the side surface of the second interlayer connection portion 6d when the above surface is the upper surface. As in the wiring circuit board of FIG. 5, by forming the interlayer connection portion 6 from the first interlayer connection portion 6c and the second interlayer connection portion 6d, in other words, by forming the interlayer connection portion 6 in two steps, it is possible to form the interlayer connection portion 6 while avoiding via filling which is technically difficult to perform by forming the interlayer connection portion 6 at once.

[0042] An embodiment of the manufacturing method of the wiring circuit board shown in FIG. 5 will be described with reference to FIGS. 6A to 6G. First, a laminate shown in FIG. 6A is produced. The laminate shown in FIG. 6A has the same structure as the laminate shown in FIG. 2G. Therefore, the laminate shown in FIG. 6A can be produced, for example, by the method described with reference to FIGS. 2A to 2G.

[0043] Next, the first interlayer connection portion 6c is formed in the through hole 10a so as not to be in contact with the metal core layer 10 and to be in contact with the first conductor layer 2 (FIG. 6B). The formation of the first interlayer connection portion 6c can be performed, for example, as follows. · Formation of a photoresist film (not shown) on the metal core layer 10 · Formation of a resist pattern by selective exposure and development of the photoresist film (exposure of the first conductor layer 2 through the through hole 10a) · Plating on the exposed first conductor layer 2 · Removal of the photoresist film At this time, plating is performed so that the thickness (height) of the first interlayer connection portion 6c is thinner than the thickness of the metal core layer 10. As described above, the first interlayer connection portion 6c is formed.

[0044] Next, a second interlayer connection portion 6d is formed on the first interlayer connection portion 6c (FIG. 6C). The second interlayer connection portion 6d can be formed, for example, as follows. · Formation of a photoresist film (not shown) on the metal core layer 10, on the first interlayer connection portion 6c, and in the through hole 10a · Formation of a resist pattern by selective exposure and development of the photoresist film (exposure of the first interlayer connection portion 6c) · Plating on the exposed first interlayer connection portion 6c · Removal of the photoresist film As described above, the interlayer connection portion 6 having the first interlayer connection portion 6c and the second interlayer connection portion 6d is formed. Note that plating is performed so that the total thickness (height) of the first interlayer connection portion 6c and the second interlayer connection portion 6d is thicker than the thickness of the metal core layer 10. By doing so, the interlayer connection portion 6 protrudes from the surface of the metal core layer 10.

[0045] Next, a second insulating layer precursor 7a is formed on the metal core layer 10 so as to cover the interlayer connection portion 6 (FIG. 6D). The second insulating layer precursor 7a is in a layer shape. The second insulating layer precursor 7a can be formed, for example, by laminating a B-stage insulating resin film and forming an insulating layer by hot pressing.

[0046] Next, the second insulating layer precursor 7a is thinned to form the second insulating layer 7 so that the interlayer connection portion 6 protrudes and is exposed from the second insulating layer precursor 7a (FIG. 6E). Examples of the method for thinning the second insulating layer precursor 7a include etching.

[0047] Next, a patterned second conductor layer 8 is formed on the second insulating layer 7 and the interlayer connection portion 6 (FIG. 6F). The formation of the second conductor layer 8 can be performed, for example, as follows. · Formation of a seed layer (not shown) on the second insulating layer 7 and the interlayer connection portion 6 · Formation of a photoresist film (not shown) on the seed layer · Formation of a resist pattern by selective exposure and development of the photoresist film (partial exposure of the seed layer) · Electrolytic plating on the exposed seed layer · Removal of the photoresist film and removal of the unnecessary seed layer The formed patterned electrolytic plating layer becomes the second conductor layer 8. As described above, the second conductor layer 8 is formed. At this time, a part 8a of the second conductor layer and the interlayer connection portion 6 in contact with the part 8a of the second conductor layer serve as external connection terminals. And by forming a part 8a of the second conductor layer so as to cover the interlayer connection portion 6, a part 8a of the second conductor layer and the interlayer connection portion 6 are in contact with each other on the surface in the thickness direction of the wiring circuit board at the interlayer connection portion 6, and a part 8a of the second conductor layer and the interlayer connection portion 6 are also in contact with each other at a part of the side surface of the interlayer connection portion 6 when the above surface is the upper surface.

[0048] Next, a third insulating layer 9 having an opening 9a is formed so as to cover the second conductor layer 8 and expose the external connection terminal (FIG. 6G). The formation of the third insulating layer 9 having the opening 9a can be performed, for example, as follows. · Laminating a B-stage insulating resin film and thermal pressing · Forming the opening 9a by laser irradiation or the like on the insulating layer As described above, the wiring circuit board shown in FIG. 5 (FIG. 6G) is obtained.

[0049] (Semiconductor Package) The semiconductor package of the present invention includes the wiring circuit board of the present invention. The semiconductor package includes, for example, a semiconductor chip connected to the wiring circuit board. The semiconductor package includes, for example, a sealing resin for sealing the semiconductor chip. Examples of semiconductor packages include, for example, FC-CSP (Flip Chip-Chip Scale Package), MIS-BGA (Molded Interconnect Substrate-Ball Grid Array) package, ETS-BGA (Embedded Trace Substrate-Ball Grid Array) package, Fan-out type WLP (Wafer Level Package), Fan-in type WLP, Fan-out type PLP (Panel Level Package), Fan-in type PLP, FC-BGA type (Flip Chip-Chip, -Ball Grid Array), 2.5D and 3D packages for high-end applications, etc.

[0050] (Electronic device) The electronic device of the present invention includes the semiconductor package of the present invention. The electronic device is not particularly limited. For example, ICT infrastructure devices such as servers, routers, supercomputers, mainframes, and workstations; antennas such as GPS antennas, wireless base station antennas, millimeter wave antennas, and RFID antennas; communication devices such as mobile phones, smartphones, PHS, PDAs, and tablet terminals; digital devices such as personal computers, TVs, digital cameras, digital video cameras, POS terminals, wearable terminals, and digital media players; in-vehicle electronic devices such as electronic control system devices, in-vehicle communication devices, car navigation devices, millimeter wave radars, and in-vehicle camera modules; semiconductor test devices, high-frequency measurement devices, etc.

Description of reference numerals

[0051] First insulating layer 1 Opening 1a First conductor layer 2 Fourth insulating layer 3 Opening 3a Third conductor layer 4 Fifth insulating layer 5 Opening 5a Interlayer connection portion 6 First interlayer connection portion 6a Second interlayer connection portion 6b First layer connection part 6c Second layer connection part 6d Second insulating layer 7 Precursor of the second insulating layer 7a Second conductor layer 8 Part of the second conductor layer 8a Third insulating layer 9 Opening 9a Metal core layer 10 Through hole 10a

Claims

1. A first insulating layer, A first conductor layer disposed on the first insulating layer, A second insulating layer located on the side of the first insulating layer opposite to the first conductor layer side, A second conductor layer disposed on the second insulating layer, A third insulating layer disposed on the second conductor layer and having an opening, An interlayer connection portion that electrically connects the first conductor layer and the second conductor layer, A wiring circuit board having: The opening is formed on an extension line of the interlayer connection portion in the thickness direction of the wiring circuit board, The second conductor layer exposed by the opening and the interlayer connection portion in contact with the second conductor layer constitute an external connection terminal, The second conductor layer and the interlayer connection portion are in contact with each other on a plane in the thickness direction of the wiring circuit board in the interlayer connection portion, and the second conductor layer and the interlayer connection portion are also in contact with each other at a part of the side surface of the interlayer connection portion when the plane is the upper surface, A wiring circuit board.

2. The wiring circuit board according to claim 1, wherein the second conductor layer has a wiring.

3. The wiring circuit board according to claim 1, wherein a cross-sectional shape of the interlayer connection portion is rectangular in a cross-section parallel to the thickness direction of the wiring circuit board.

4. The wiring circuit board according to claim 1, wherein a cross-sectional shape of the interlayer connection portion is a trapezoid having a first base on the second conductor layer side and a second base shorter than the first base on the first conductor layer side in a cross-section parallel to the thickness direction of the wiring circuit board.

5. The wiring circuit board according to claim 1, wherein the second conductor layer and the interlayer connection portion are in contact with each other on all planes in the thickness direction of the wiring circuit board in the interlayer connection portion, and the second conductor layer and the interlayer connection portion are also in contact with each other at a part of the side surface of the interlayer connection portion when the plane is the upper surface and at a part that goes around the side surface.

6. Further comprising a metal core layer having a through hole, The metal core layer is disposed between the first insulating layer and the second insulating layer, The interlayer connection portion penetrates through the through hole of the metal core layer, The wiring circuit board according to claim 1.

7. The wiring circuit board according to claim 1, wherein the interlayer connection portion has a first interlayer connection portion and a second interlayer connection portion arranged in the thickness direction of the wiring circuit board.

8. A semiconductor package including the wiring circuit board according to any one of claims 1 to 7.

9. An electronic device including the semiconductor package according to claim 8.

10. A method for manufacturing a wiring circuit board, which manufactures the wiring circuit board according to any one of claims 1 to 7, A step of forming a second insulating layer precursor so as to cover the interlayer connection portion, A step of thinning the second insulating layer precursor so that the interlayer connection portion protrudes from the second insulating layer precursor and is exposed, and forming the second insulating layer, A step of forming a second conductor layer on the second insulating layer and the interlayer connection portion, A method for manufacturing a wiring circuit board, including:

11. The method for manufacturing a wiring circuit board according to claim 10, further comprising a step of forming a third insulating layer having an opening so that an external connection terminal formed by the second conductor layer and the interlayer connection portion in contact with the second conductor layer is exposed through the opening.

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