Wiring circuit board, and method for manufacturing a wiring circuit board

Abstract

To provide a wiring circuit board that can suppress the generation of voids during sealing without reducing the effectiveness of reinforcing the wiring circuit board with a metal reinforcement layer. [Solution] A wiring circuit board having a wiring structure layer having an insulating layer and a wiring layer, and a metal reinforcement layer in contact with one surface of the wiring structure layer, wherein the surface of the metal reinforcement layer opposite to the wiring structure layer side is exposed, the metal reinforcement layer has an opening that penetrates in the thickness direction to allow a semiconductor chip to be connected to the wiring circuit board, and when the line on the surface of the metal reinforcement layer opposite to the wiring structure layer side is called line (A) and the line on the wiring structure layer side is called line (B), when the intersection point of one side line of the opening with line (A) is called intersection point (a) and the intersection point with line (B) is called intersection point (b), when the line connecting intersection point (a) and intersection point (b) is called line segment (C), and when the line on the opposite side of the opening side starting from intersection point (b) of line (B) is called a half-line (BH), the angle (α) between the half-line (BH) and line segment (C) is less than 90°.

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, for example, 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 semiconductor device having a wiring circuit board and a semiconductor chip, for example, a semiconductor chip, a first region which is disposed under the semiconductor chip and is a region where the semiconductor chip is mounted, and a substrate having a second region which is a region where a conductor element including at least one of a circuit pattern and an electrical component is provided, and an insulating sheet covering the conductor element, have been proposed (see Patent Document 1). Further, as a wiring circuit board, for example, a substrate including a plurality of wiring layers, a first metal post disposed on the substrate and connected to at least a part of the wiring layer disposed on the uppermost side among the plurality of wiring layers, a second metal post disposed on the substrate and connected to at least another part of the wiring layer disposed on the uppermost side among the plurality of wiring layers, a resist layer disposed on the substrate and embedding at least a part of each of the first metal post and the second metal post, and a metal via penetrating the resist layer on the second metal post and connected to the second metal post, have been proposed (see Patent Document 2). In one embodiment of these proposed technologies, a stiffener is attached to the substrate or the printed circuit board in order to reduce distortion and warpage (see, for example, paragraph

[0018] of Patent Document 1 and paragraph

[0023] of Patent Document 2).

[0004] Furthermore, a rewiring board has been proposed for use in electrically connecting a first electrical element and a second electrical element, comprising: a first insulating layer having first and second main surfaces facing opposite directions; a first terminal portion formed to be exposed on the first main surface of the first insulating layer; a second terminal portion formed to be exposed on the second main surface of the first insulating layer; a conductor layer connecting the first terminal portion and the second terminal portion within the first insulating layer; a metal support formed on the first main surface of the first insulating layer and having an opening; and a second insulating layer formed on the inner surface of the opening of the metal support, wherein the opening is provided to overlap the first terminal portion in a first view perpendicular to the first main surface of the first insulating layer; the first terminal portion is provided to be electrically connectable to the first electrical element through or within the opening; and the second terminal portion is provided to be electrically connectable to the second electrical element (see Patent Document 3). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-118943 [Patent Document 2] Japanese Patent Publication No. 2024-18878 [Patent Document 3] International Publication No. 2023 / 080097 Brochure [Overview of the project] [Problems that the invention aims to solve]

[0006] Providing a metal reinforcing layer (metal support), such as a stiffener, on the surface of a circuit board is effective in reinforcing the circuit board (reducing warping and distortion). Typically, stiffeners have openings, within which semiconductor chips are placed. For reinforcing the circuit board, it is preferable that the openings in the metal reinforcing layer be small. Here, a wiring circuit board in which a semiconductor chip is placed within an opening in a metal reinforcement layer is sealed with a sealing resin composition after being placed on another substrate such as a motherboard, in order to protect the semiconductor chip and the wiring circuit board. However, if the gap between the edge of the opening in the metal reinforcement layer and the semiconductor chip is narrow during sealing, the sealing resin composition may not be able to sufficiently penetrate the gap, and voids may remain within the opening in the metal reinforcement layer after sealing. If voids remain, the mechanical strength will be weakened, leading to defects such as cracks and chips. In this respect, it is preferable for the opening in the metal reinforcement layer to be larger. Thus, in terms of reinforcing the wiring circuit board, smaller openings in the metal reinforcement layer are preferable, while in terms of reducing voids during sealing, larger openings in the metal reinforcement layer are preferable, and it is desirable to achieve both of these conditions.

[0007] The present invention aims to provide a wiring circuit board that can suppress the generation of voids during sealing without reducing the reinforcing effect of the wiring circuit board by a metal reinforcement layer, a method for manufacturing the wiring circuit board, a semiconductor package including the wiring circuit board, and an electronic device. [Means for solving the problem]

[0008] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, found that they could solve the above problems, and completed the present invention having the following gist. In other words, the present invention encompasses the following:

[0009] [1] A wiring circuit board having a wiring structure layer having an insulating layer and a wiring layer, and a metal reinforcing layer in contact with one surface of the wiring structure layer, The surface of the metal reinforcement layer opposite to the wiring structure layer is exposed. The metal reinforcement layer has an opening for connecting the semiconductor chip to the wiring circuit board, the opening having a penetration in the thickness direction of the metal reinforcement layer. In the cross-section of the metal reinforcement layer in the thickness direction and including the opening, Let line (A) be the line on the surface of the metal reinforcement layer opposite to the wiring structure layer. Let line (B) be the line that is the surface of the metal reinforcement layer on the wiring structure layer side. The shape of the opening has two side lines, and the intersection point of one of the two side lines with line (A) is defined as intersection point (a), and the intersection point of the other side line with line (B) is defined as intersection point (b). Let the line connecting intersection point (a) and intersection point (b) be line segment (C). Of the lines (B) mentioned above, when the line on the opposite side from the opening, starting from the intersection point (b), is defined as a half-line (BH), The angle (α) between the aforementioned half-line (BH) and the aforementioned line segment (C) is less than 90°. Wiring circuit board. [2] The wiring circuit board according to [1], wherein the angle (α) is 45° or more and less than 90°. [3] The wiring circuit board according to [1] or [2], wherein the metal reinforcing layer has a second opening that penetrates the metal reinforcing layer in the thickness direction, in addition to the opening. [4] The metal reinforcing layer has, in addition to the opening, a second opening and a third opening that penetrate the metal reinforcing layer in the thickness direction, In any cross-section (X) in the thickness direction of the metal reinforcement layer, the second opening and the third opening are formed so as to sandwich the opening. A wiring circuit board as described in [1] or [2]. [5] The wiring circuit board according to [4], wherein the cross-section of the metal reinforcement layer in the thickness direction, in a cross-section (Y) perpendicular to the cross-section (X), the metal reinforcement layer does not have an opening that penetrates the metal reinforcement layer in the thickness direction. [6] The metal reinforcing layer further has a fourth opening that penetrates the metal reinforcing layer in the thickness direction, The cross-section (Y) in the thickness direction of the metal reinforcement layer is formed such that the cross-section (Y) perpendicular to the cross-section (X) includes the fourth opening. [4] The wiring circuit board described above. [7] The wiring circuit board according to any one of [1] to [6], wherein the wiring structure layer has an insulating layer other than the insulating layer and a wiring layer other than the wiring layer in the opening of the metal reinforcing layer. [8] The wiring circuit board according to any one of [1] to [6], wherein the wiring structure layer does not have an insulating layer other than the insulating layer and a wiring layer other than the wiring layer in the opening of the metal reinforcing layer. [9] A semiconductor package including the wiring circuit board according to any one of [1] to [8].

[10] An electronic device including the semiconductor package according to [9].

[11] A method for manufacturing a wiring circuit board, which manufactures the wiring circuit board according to any one of [1] to [8], including a step of forming an opening penetrating in the thickness direction of the metal reinforcing layer in the metal reinforcing layer, wherein the step of forming the opening includes forming the opening so that the angle (α) is less than 90°. A method for manufacturing a wiring circuit board.

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

[11] , wherein the step of forming the opening includes forming the opening so that the angle (α) is less than 90° by wet etching. [Effect of the Invention]

[0010] According to the present invention, it is possible to provide a wiring circuit board capable of suppressing the generation of voids during sealing without reducing the effect of reinforcing the wiring circuit board by a metal reinforcing layer, a method for manufacturing the wiring circuit board, a semiconductor package including the wiring circuit board, and an electronic device. [Brief Description of the Drawings]

[0011] [Figure 1A] FIG. 1A is a schematic view of an embodiment of a wiring circuit board. [Figure 1B] FIG. 1B is a schematic view of an embodiment of a wiring circuit board. [Figure 2A] FIG. 2A is a top view of another embodiment of a wiring circuit board. [Figure 2B] Figure 2B is a cross-sectional view taken along the line X-X of the wiring circuit board of Figure 2A. [Figure 2C] Figure 2C is a cross-sectional view taken along the line Y-Y of the wiring circuit board of Figure 2A. [Figure 3A] Figure 3A is a top view of another embodiment of the wiring circuit board. [Figure 3B] Figure 3B is a cross-sectional view taken along the line X-X of the wiring circuit board of Figure 3A. [Figure 3C] Figure 3C is a cross-sectional view taken along the line Y-Y of the wiring circuit board of Figure 3A. [Figure 4A] Figure 4A is a schematic diagram (part 1) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 4B] Figure 4B is a schematic diagram (part 2) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 4C] Figure 4C is a schematic diagram (part 3) for explaining an example of a method for manufacturing a wiring circuit board. <了 [Figure 4D] Figure 4D is a schematic diagram (part 4) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 4E] Figure 4E is a schematic diagram (part 5) for explaining an example of a method for manufacturing a wiring circuit board. [[ID=2i]]c [Figure 4F] Figure 4F is a schematic diagram (part 6) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 4G] Figure 4G is a schematic diagram (part 7) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 4H] Figure 4H is a schematic diagram (part 8) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 4I] Figure 4I is a schematic diagram (part 9) for explaining an example of a method for manufacturing a wiring circuit board. [Figure 5] Figure 5 is a schematic diagram of another embodiment of the wiring circuit board. [Figure 6] Figure 6 is a schematic diagram of another embodiment of the wiring circuit board. [Figure 7] Figure 7 is a schematic diagram of another embodiment of the wiring circuit board. [Figure 8A] Figure 8A is a schematic diagram of another embodiment of a wiring circuit board. [Figure 8B] Figure 8B is a schematic diagram of another embodiment of the wiring circuit board. [Figure 9A] Figure 9A is a schematic diagram of one embodiment of a wiring circuit board. [Figure 9B] Figure 9B shows an example of the structure of region X of the wiring circuit board in Figure 9A. [Figure 9C] Figure 9C shows another example of the structure of region X of the wiring circuit board in Figure 9A. [Figure 9D] Figure 9D shows another example of the structure of region X of the wiring circuit board in Figure 9A. [Figure 9E] Figure 9E shows another example of the structure of region X of the wiring circuit board in Figure 9A. [Figure 10] Figure 10 is a schematic diagram of an example of a wiring circuit board to which semiconductor chips are connected. [Modes for carrying out the invention]

[0012] (Wiring circuit board, and method for manufacturing a wiring circuit board) The wiring circuit board of the present invention comprises a wiring structure layer and a metal reinforcement layer. The metal reinforcement layer is in contact with one surface of the wiring structure layer. The wiring structure layer comprises an insulating layer and a wiring layer. The wiring structure layer may further comprise a second insulating layer, a third insulating layer, a fourth insulating layer, a fifth insulating layer, a second wiring layer, a third wiring layer, a fourth wiring layer, and so on. In a wiring circuit board, the surface of the metal reinforcement layer opposite to the wiring structure layer is exposed. The metal reinforcement layer has openings that allow the semiconductor chip to be connected to the wiring circuit board, and the openings penetrate the metal reinforcement layer in the thickness direction. In a cross-section of the metal reinforcement layer in the thickness direction and including an opening, Let line (A) be the line on the surface of the metal reinforcement layer opposite to the wiring structure layer. Let line (B) be the line that is the surface of the wiring structure layer in the metal reinforcement layer. The shape of the opening has two side lines, and the intersection point of one of the two side lines with line (A) is called intersection point (a), and the intersection point of the other side line with line (B) is called intersection point (b). Let the line connecting intersection point (a) and intersection point (b) be line segment (C). When the line (B) is divided into two halves, with the intersection point (b) as the starting point and the line on the opposite side of the opening being defined as a half-line (BH), The angle (α) between the ray (BH) and the line segment (C) is less than 90°.

[0013] An example of the wiring circuit board of the present invention will be described below with reference to Figures 1A and 1B. Figures 1A and 1B are schematic cross-sectional views of an example of a wiring circuit board. The wiring circuit boards in Figures 1A and 1B have the same structure. However, Figure 1B includes auxiliary lines to illustrate the angle (α). The wiring circuit board 100 has a metal reinforcement layer 1 and a wiring structure layer 2. The metal reinforcement layer 1 is in contact with one surface of the wiring structure layer 2. The surface of the metal reinforcement layer 1 opposite to the wiring structure layer 2 is exposed. The metal reinforcement layer 1 has an opening 1a that penetrates the metal reinforcement layer 1 in the thickness direction, which allows the semiconductor chip to be connected to the wiring circuit board 100. The wiring structure layer 2 has an insulating layer 21 and a wiring layer 22. The wiring structure layer 2 further has a second insulating layer 23, a second wiring layer 24, a third insulating layer 25, a third wiring layer 26, and a fourth insulating layer 27. In the wiring structure layer 2, the insulating layer 21, the wiring layer 22, the second insulating layer 23, the second wiring layer 24, the third insulating layer 25, the third wiring layer 26, and the fourth insulating layer 27 are provided in this order. The insulating layer 21 is in contact with the metal reinforcement layer 1. The wiring layer 22 has a pattern. The second insulating layer 23 covers the wiring layer 22 while filling the gaps in the pattern of the wiring layer 22. The second wiring layer 24 has a pattern. The third insulating layer 25 covers the second wiring layer 24 while filling the gaps in the pattern of the second wiring layer 24. The third wiring layer 26 has a pattern. The fourth insulating layer 27 covers the third wiring layer 26 while filling the gaps in the pattern of the third wiring layer 26. On the other hand, a part of the third wiring layer 26 is exposed through holes in the fourth insulating layer 27. A portion of the wiring layer 22 fills the through-holes in the insulating layer 21. A portion of the second wiring layer 24 fills the through-holes in the second insulating layer 23. A portion of the third wiring layer 26 fills the through-holes in the third insulating layer 25. A portion of the wiring layer 22 is electrically in contact with a portion of the second wiring layer 24. A portion of the second wiring layer 24 is electrically in contact with a portion of the third wiring layer 26. In the wiring circuit board 100 shown in Figures 1A and 1B, a portion of the wiring layer 22 that fills the through-holes in the insulating layer 21 is exposed at the opening 1a of the metal reinforcement layer 1. The portion of the wiring layer 22 exposed at the opening 1a is used as a terminal for connection to a semiconductor chip.

[0014] In the wiring circuit board 100 shown in Figures 1A and 1B, the cross-sectional shape of the opening 1a in the thickness direction of the metal reinforcement layer 1 is tapered, where the width of the opening 1a on the surface of the metal reinforcement layer 1 facing the wiring structure layer 2 is narrower than the width of the opening 1a on the surface of the metal reinforcement layer 1 facing the wiring structure layer 2. Here, the width of the opening 1a is the length in the direction perpendicular to the thickness direction of the metal reinforcement layer 1. That is, in the cross-section of the metal reinforcement layer 1 in the thickness direction and including the opening 1a, Let line (A) be the line on the surface of the metal reinforcement layer 1 opposite to the wiring structure layer 2. Let line (B) be the line that is the surface of the wiring structure layer 2 side in the metal reinforcement layer 1. The shape of the opening 1a has two side lines, and the intersection point of one of the two side lines 1aa with line (A) is called intersection point (a), and the intersection point of the other side line 1aa with line (B) is called intersection point (b). Let the line connecting intersection point (a) and intersection point (b) be line segment (C). When the line (B) is divided into two halves, with the intersection point (b) as the starting point and the line on the opposite side of the opening 1a being defined as a half-line (BH), The angle (α) between the ray (BH) and the line segment (C) is less than 90°.

[0015] When determining the angle (α), it is preferable that the cross-section is perpendicular to the edge of the opening (for example, the XX and YY cross-sections in Figures 2A and 3A). If the shape of the opening as viewed from the thickness direction is polygonal, it is preferable that the cross-section when determining the angle (α) is perpendicular to the relatively longest side of the polygon (for example, the longest side). Furthermore, the cross-section when determining the angle (α) only needs to be perpendicular to the edge at any point on the edge of the opening, but it is preferable that it be perpendicular to the edge near the center. In addition, as long as it can be confirmed that the angle (α) is less than 90°, the edge and the cross-section do not need to intersect at a perfect 90° angle, but it is sufficient if they intersect at an angle close to 90°.

[0016] Thus, in the wiring circuit board, the metal reinforcement layer 1 has a structure such that the angle (α) is less than 90°. By doing so, the opening area of ​​the opening 1a on the surface of the metal reinforcement layer 1 opposite to the wiring structure layer 2 can be increased, so that when a semiconductor chip is placed on the opening 1a, the gap between the edge of the opening 1a in the metal reinforcement layer 1 and the semiconductor chip can be widened. In addition, the shape of the opening 1a becomes mortar-shaped. As a result, the sealing resin composition can sufficiently penetrate the gap, and the retention of voids in the opening 1a of the metal reinforcement layer 1 after sealing can be suppressed. Furthermore, because the opening area of ​​the opening 1a on the surface of the metal reinforcement layer 1 on the wiring structure layer 2 side is small, the volume of the metal portion of the metal reinforcement layer 1 can be increased. As a result, it is possible to prevent a decrease in the reinforcing effect of the metal reinforcement layer 1.

[0017] The angle (α) should be less than 90°, and there is no particular lower limit. However, the angle (α) is preferably 45° or more, more preferably 50° or more, and particularly preferably 55° or more, in order to prevent the opening area on the surface of the metal reinforcement layer opposite to the wiring structure layer from becoming too large, and as a result, to prevent the volume of the metal portion of the metal reinforcement layer from becoming too small. The angle (α) does not need to be more than 90°, and is preferably 85° or less, more preferably 80° or less, and particularly preferably 75° or less, as this allows for a wider gap between the edge of the opening of the metal reinforcement layer and the semiconductor chip when the semiconductor chip is placed in the opening.

[0018] A metal reinforcement layer is, for example, an element used to ensure the rigidity of a wiring circuit board. The material of the metal reinforcement layer is not particularly limited and includes, for example, Cu, Cu alloys, Al, stainless steel, FeNi alloys such as 42 alloy, and combinations thereof. Among these, Cu, Cu alloys, Al, and stainless steel are preferred from the viewpoint of thermal conductivity and electrical conductivity. The thickness of the metal reinforcement layer is not particularly limited, but is, for example, 10 μm or more, preferably 15 μm or more, and also, for example, 100 μm or less, preferably 75 μm or less. In this invention, "thickness" refers to the length of the metal reinforcement layer in the thickness direction. The thickness direction of the metal reinforcement layer refers to the direction perpendicular to the surface direction of the metal reinforcement layer.

[0019] The material of the insulating layers in the wiring structure layer (e.g., insulating layer, second insulating layer, third insulating layer, fourth insulating layer, fifth insulating layer) is not particularly limited, and examples include synthetic resins. Examples of synthetic resins include polyimide resin, epoxy resin, polyethernitrile, polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, and polyvinyl chloride. Polyimide resin and epoxy resin are preferred because they have excellent heat resistance, low coefficient of linear expansion, and dielectric strength. The insulating layer may or may not contain fillers, but if it does not contain fillers, it has excellent insulating properties and excellent suppression of electrical leakage. The insulating layer may or may not contain glass fibers. An insulating layer containing glass fibers may be made by impregnating a glass fiber cloth with a synthetic resin, such as a glass epoxy represented by FR4 (Flame Retardant Type 4). The thickness of the insulating layer is not particularly limited, but is, for example, 1 μm or more, preferably 3 μm or more, and also, for example, 35 μm or less, preferably 20 μm or less.

[0020] Examples of materials for the wiring layers in the wiring structure (e.g., the first wiring layer, second wiring layer, third wiring layer, fourth wiring layer) include metallic materials. Examples of metallic materials include copper, nickel, gold, solder, and alloys thereof. The thickness of the wiring layer is not particularly limited, and is, for example, 3 μm or more, preferably 5 μm or more, and also, for example, 50 μm or less, preferably 30 μm or less.

[0021] The wiring structure layer may have a seed layer (not shown). The seed layer is used as a conductive layer for electroplating. Examples of materials for the seed layer include copper, chromium, nickel, and alloys thereof.

[0022] The metal reinforcement layer may have openings other than those that allow the semiconductor chip to be connected to the wiring circuit board. Such openings are, for example, openings that penetrate the metal reinforcement layer in the thickness direction. Such openings are formed, for example, to reduce warping of the wiring structure layer.

[0023] Furthermore, the metal reinforcement layer may have second and third openings in addition to the opening (first opening) for connecting the semiconductor chip to the wiring circuit board. Such openings are, for example, openings that penetrate the metal reinforcement layer in the thickness direction. Such openings are formed, for example, to reduce warping of the wiring structure layer. The second and third openings are formed, for example, in any cross-section (X) in the thickness direction of the metal reinforcement layer, so as to sandwich the first opening. This embodiment will be described later with reference to Figures 2A and 2B.

[0024] A portion of the wiring layer may be exposed at the second opening as a terminal. A portion of the wiring layer may be exposed at the third opening as a terminal.

[0025] In one example of a wiring circuit board, the metal reinforcement layer, in a cross-section in the thickness direction of the metal reinforcement layer, does not have an opening that penetrates the metal reinforcement layer in the thickness direction in a cross-section (Y) perpendicular to the aforementioned cross-section (X). This embodiment will be described later with reference to Figures 2A to 2C.

[0026] In another example of a wiring circuit board, the metal reinforcement layer has a fourth opening in addition to the first, second, and third openings. The fourth opening is an opening that penetrates the metal reinforcement layer in the thickness direction. In this example, the fourth opening is a cross-section (Y) in the thickness direction of the metal reinforcement layer, and is formed such that the cross-section (Y) perpendicular to the aforementioned cross-section (X) includes the fourth opening.

[0027] In another example of a wiring circuit board, the metal reinforcement layer has a fourth and a fifth opening, in addition to the first, second, and third openings. The fourth and fifth openings are openings that penetrate the metal reinforcement layer in the thickness direction. For example, the fourth and fifth openings are formed such that the cross-section (Y) in the thickness direction of the metal reinforcement layer, perpendicular to the aforementioned cross-section (X), includes the fourth and fifth openings. The fourth and fifth openings are formed, for example, in the aforementioned cross-section (Y), so as to sandwich the first opening. This embodiment will be described later with reference to Figures 3A to 3C.

[0028] A portion of the wiring layer may be exposed at the fourth opening as a terminal. A portion of the wiring layer may be exposed at the fifth opening as a terminal.

[0029] The wiring structure layer may have an insulating layer other than the insulating layer and another wiring layer other than the wiring layer within the opening of the metal reinforcement layer. This embodiment will be described later with reference to Figures 5 and 6. The wiring structure layer does not necessarily have to have other insulating layers other than the insulating layer, or other wiring layers other than the wiring layer, within the openings of the metal reinforcement layer. Examples of this embodiment include those shown in Figures 1A and 1B.

[0030] Figures 2A and 2C show another example of a wiring circuit board. Figure 2A is a top view of an example of a wiring circuit board. Figure 2B is a cross-sectional view of XX in Figure 2A. The XX cross-section is perpendicular to the side of opening 1a. Figure 2C is a cross-sectional view of the YY section of Figure 2A. Note that the YY section is perpendicular to the XX section. Also, the YY section is perpendicular to the side of opening 1a. In the wiring circuit board 100 shown in Figures 2A to 2C, the metal reinforcement layer 1 has a second opening 1b and a third opening 1c in addition to the opening 1a. As shown in Figure 2B, the second opening 1b penetrates the metal reinforcement layer 1 in the thickness direction. As shown in Figure 2B, the third opening 1c penetrates the metal reinforcement layer 1 in the thickness direction. In Figure 2A, the shape of the opening 1a is approximately rectangular when viewed from above. In Figure 2A, the four corners of the rectangle are chamfered, but the four corners may be right angles. In the cross-sectional view of XX in Figure 2B, the second opening 1b and the third opening 1c are formed so as to sandwich the opening 1a. Furthermore, in the YY cross-sectional view of Figure 2C, the metal reinforcement layer 1 does not have an opening that penetrates the metal reinforcement layer 1 in the thickness direction. As shown in Figure 2B, in the wiring structure layer 2, a portion of the wiring layer 22 may be exposed as terminals through the second opening 1b and the third opening 1c.

[0031] Figures 3A to 3C show another example of a wiring circuit board. Figure 3A is a top view of an example of a wiring circuit board. Figure 3B is a cross-sectional view of XX in Figure 3A. The XX cross-section is perpendicular to the side of opening 1a. Figure 3C is a cross-sectional view of the YY section of Figure 3A. Note that the YY section is perpendicular to the XX section. Also, the YY section is perpendicular to the side of opening 1a. In the wiring circuit board 100 shown in Figures 3A to 3C, the metal reinforcement layer 1 has a second opening 1b, a third opening 1c, a fourth opening 1d, and a fifth opening 1e, in addition to the opening 1a. As shown in Figure 3B, the second opening 1b penetrates the metal reinforcement layer 1 in the thickness direction. As shown in Figure 3B, the third opening 1c penetrates the metal reinforcement layer 1 in the thickness direction. As shown in Figure 3C, the fourth opening 1d penetrates the metal reinforcement layer 1 in the thickness direction. As shown in Figure 3C, the fifth opening 1e penetrates the metal reinforcement layer 1 in the thickness direction. In Figure 3A, the shape of the opening 1a is approximately rectangular when viewed from above. In Figure 3A, the four corners of the rectangle are chamfered, but the four corners may be right angles. In the cross-sectional view of XX in Figure 3B, the second opening 1b and the third opening 1c are formed so as to sandwich the opening 1a. In the YY cross-sectional view of Figure 3C, the fourth opening 1d and the fifth opening 1e are formed so as to sandwich opening 1a. As shown in Figures 3B and 3C, in the wiring structure layer 2, a portion of the wiring layer 22 may be exposed as terminals through the second opening 1b, the third opening 1c, the fourth opening 1d, and the fifth opening 1e.

[0032] There are no particular restrictions on the area of ​​the openings in the metal reinforcement layer, but the total area of ​​the openings when the metal reinforcement layer is viewed from the thickness direction (top view) is preferably 60% to 99% of the total area of ​​the metal reinforcement layer when viewed from the thickness direction, and preferably 70% to 95%. If it is above the lower limit, it is advantageous in that a larger semiconductor chip can be placed, and if it is below the upper limit, it is advantageous in that warping is prevented. Note that the total area of ​​the metal reinforcement layer when viewed from the thickness direction (top view) is the total area of ​​opening 1a, the second opening 1b, and the third opening 1c in the case of Figure 2A. The total area of ​​the metal reinforcement layer when viewed from the thickness direction is the total area of ​​the metal reinforcement layer including opening 1a, the second opening 1b, and the third opening 1c in the case of Figure 2A.

[0033] The present invention's method for manufacturing a wiring circuit board includes the step of forming an opening in the metal reinforcement layer that penetrates in the thickness direction of the metal reinforcement layer. The step of forming the opening includes forming the opening such that the angle (α) is less than 90°. There are no particular limitations on the method for forming an opening such that the angle (α) is less than 90°, but etching is one example. Wet etching is one example of etching. Methods for forming openings by wet etching include, for example, the following methods (1) to (4). (1) Formation of a photoresist film on the surface opposite to the wiring structure layer in the metal reinforcement layer (2) Formation of a resist pattern by selective exposure and development of the photoresist film (partial exposure of the metal reinforcement layer) (3) Wet etching of the exposed metal reinforcement layer (for example, wet etching using ferric chloride) (4) Removal of the photoresist film One method for controlling the angle (α) is to control it by adjusting the spray pressure when wet etching the metal reinforcement layer using a spray method. For example, by reducing the spray pressure, the angle (α) can be reduced.

[0034] In the method for manufacturing a wiring circuit board, the method for forming the wiring structure layer is not particularly limited.

[0035] One embodiment of the manufacturing method for the wiring circuit board shown in Figures 1A and 1B will be explained using Figures 4A to 4I. First, prepare the metal reinforcement layer 1 (Figure 4A).

[0036] Next, an insulating layer 21 having through holes 21a is formed on one surface of the metal reinforcement layer 1 (Figure 4B). The insulating layer 21 having through holes 21a can be formed, for example, as follows. • Coating and drying of a photosensitive resin composition containing photosensitive polyimide • Selective exposure and development of the formed photosensitive polyimide film

[0037] Next, a patterned wiring layer 22 is formed on the insulating layer 21 and within the through-hole 21a (Figure 4C). The wiring layer 22 can be formed, for example, as follows. Formation of a seed layer (not shown) on the insulating layer 21 • Formation of a photoresist film (not shown) on the seed layer • Formation of a resist pattern by selective exposure and development of a photoresist film (partial exposure of the seed layer) Plating onto the exposed seed layer • Removal of photoresist film and removal of unnecessary seed layer As a result, a patterned wiring layer 22 is formed. Note that a portion of the wiring layer 22 fills the through-holes in the insulating layer 21.

[0038] Next, a second insulating layer 23 having through holes 23a is formed on the wiring layer 22 (Figure 4D). The second insulating layer 23 covers the patterned wiring layer 22. The second insulating layer 23 can be formed, for example, by coating and drying a photosensitive resin composition containing photosensitive polyimide, and then selectively exposing and developing the formed photosensitive polyimide film.

[0039] Next, a patterned second wiring layer 24 is formed on the second insulating layer 23 and within the through-hole 23a (Figure 4E). The second wiring layer 24 can be formed, for example, as follows. Formation of a seed layer (not shown) on the second insulating layer 23 • Formation of a photoresist film (not shown) on the seed layer • Formation of a resist pattern by selective exposure and development of a photoresist film (partial exposure of the seed layer) Electroplating of the exposed seed layer • Removal of photoresist film and removal of unnecessary seed layer The formed patterned electroplated layer becomes the second wiring layer 24. As a result, a patterned second wiring layer 24 is formed. Note that a portion of the second wiring layer 24 fills the through-holes in the second insulating layer 23.

[0040] Next, a third insulating layer 25 having through holes 25a is formed on the second wiring layer 24 (Figure 4F). The third insulating layer 25 covers the patterned second wiring layer 24. The third insulating layer 25 can be formed, for example, by coating and drying a photosensitive resin composition containing photosensitive polyimide, and then selectively exposing and developing the formed photosensitive polyimide film.

[0041] Next, a patterned third wiring layer 26 is formed on the third insulating layer 25 and within the through-hole 25a (Figure 4G). The third wiring layer 26 can be formed, for example, as follows. Formation of a seed layer (not shown) on the third insulating layer 25 • Formation of a photoresist film (not shown) on the seed layer • Formation of a resist pattern by selective exposure and development of a photoresist film (partial exposure of the seed layer) Electroplating of the exposed seed layer • Removal of photoresist film and removal of unnecessary seed layer The formed patterned electroplated layer becomes the third wiring layer 26. As a result, a patterned third wiring layer 26 is formed. Note that a portion of the third wiring layer 26 fills the through-holes in the third insulating layer 25.

[0042] Next, a fourth insulating layer 27 having through holes 27a is formed on the third wiring layer 26 (Figure 4H). The fourth insulating layer 27 covers the patterned third wiring layer 26. The fourth insulating layer 27 can be formed, for example, by coating and drying a photosensitive resin composition containing photosensitive polyimide, and then selectively exposing and developing the formed photosensitive polyimide film. As a result, the wiring structure layer 2 is formed.

[0043] Next, an opening 1a is formed in the metal reinforcement layer 1 from the side opposite to the wiring structure layer 2 (Figure 4I). Note that Figure 4I and Figure 4H are rotated 180° from each other. The opening 1a can be formed, for example, as follows. • Formation of a photoresist film (not shown) on the surface opposite to the wiring structure layer in the metal reinforcement layer. • Formation of a resist pattern by selective exposure and development of a photoresist film (partial exposure of the metal reinforcement layer) • Wet etching of exposed metal-reinforced layers (e.g., wet etching using ferric chloride) • Removal of photoresist film As a result, the opening 1a is formed. Based on the above, the wiring circuit boards shown in Figures 1A and 1B are obtained.

[0044] Let's describe another example of a wiring circuit board. Figure 5 is a schematic cross-sectional view of another example of a wiring circuit board. The wiring circuit board 100 shown in Figure 5 has the same structure as the wiring circuit boards shown in Figures 1A and 1B, except that the wiring structure layer 2 has a fourth wiring layer 28 and a fifth insulating layer 29. The wiring circuit board 100 shown in Figure 5 has a metal reinforcement layer 1 and a wiring structure layer 2. The wiring structure layer 2 has a fourth wiring layer 28 and a fifth insulating layer 29 within the opening 1a of the metal reinforcement layer 1. The fourth wiring layer 28 has a patterned shape. The fifth insulating layer 29 covers the fourth wiring layer 28 while filling in the gaps in the pattern of the fourth wiring layer 28. A portion of the fourth wiring layer 28 is electrically in contact with a portion of the wiring layer 22. In the wiring circuit board 100 shown in Figure 5, the fifth insulating layer 29 is not in contact with the metal reinforcement layer 1.

[0045] Examples of methods for forming the fourth wiring layer 28 and the fifth insulating layer 29 include the following methods. After manufacturing the wiring circuit board shown in Figure 4I, a fourth wiring layer 28 is formed in the opening 1a. The fourth wiring layer 28 can be formed, for example, by the following method. Formation of a seed layer (not shown) on the insulating layer 21 • Formation of a photoresist film (not shown) on the seed layer • Formation of a resist pattern by selective exposure and development of a photoresist film (partial exposure of the seed layer) Plating onto the exposed seed layer • Removal of photoresist film and removal of unnecessary seed layer As a result, a patterned fourth wiring layer 28 is formed. Next, a fifth insulating layer 29 having through holes is formed on the fourth wiring layer 28. The fifth insulating layer 29 can be formed, for example, by coating and drying a photosensitive resin composition containing photosensitive polyimide, and then selectively exposing and developing the formed photosensitive polyimide film.

[0046] Let's describe another example of a wiring circuit board. Figure 6 is a schematic cross-sectional view of another example of a wiring circuit board. The wiring circuit board 100 shown in Figure 6 has the same structure as the wiring circuit boards shown in Figures 1A and 1B, except that the wiring structure layer 2 has a fourth wiring layer 28 and a fifth insulating layer 29. The wiring circuit board 100 shown in Figure 6 has a metal reinforcement layer 1 and a wiring structure layer 2. The wiring structure layer 2 has a fourth wiring layer 28 and a fifth insulating layer 29 within the opening 1a of the metal reinforcement layer 1. The fourth wiring layer 28 has a patterned shape. The fifth insulating layer 29 covers the fourth wiring layer 28 while filling in the gaps in the pattern of the fourth wiring layer 28. A portion of the fourth wiring layer 28 is electrically in contact with a portion of the wiring layer 22. In the wiring circuit board 100 shown in Figure 6, the fifth insulating layer 29 is in contact with the metal reinforcement layer 1.

[0047] Let's describe another example of a wiring circuit board. Figure 7 is a schematic cross-sectional view of another example of a wiring circuit board. The wiring circuit board 100 shown in Figure 7 has the same structure as the wiring circuit boards shown in Figures 1A and 1B, except that the wiring structure layer 2 has thermal vias. In the wiring circuit board 100 shown in Figure 7, a portion of the wiring layer 22, a portion of the second wiring layer 24, and a portion of the third wiring layer 26 are connected to form a thermal via. The thermal via is connected to the metal reinforcement layer 1. For example, heat generated within the wiring structure layer 2 can be dissipated by conducting it to the metal reinforcement layer 1 via the thermal via.

[0048] Let's describe another example of a wiring circuit board. Figures 8A and 8B are schematic cross-sectional views of another example of a wiring circuit board. The wiring circuit board 100 shown in Figures 8A and 8B has the same structure as the wiring circuit board shown in Figures 1A and 1B, except that the shape of the side surface of the opening 1a is different from the shape of the side surface of the opening 1a in the wiring circuit board shown in Figures 1A and 1B. In the wiring circuit boards shown in Figures 1A and 1B, the side shape of the opening 1a is linear in cross-section, whereas in the wiring circuit board 100 shown in Figures 8A and 8B, the side shape of the opening 1a is non-linear in cross-section. In such cases as well, the method for determining the angle (α) is as follows. In the cross-section of the metal reinforcement layer 1 in the thickness direction and including the opening 1a, Let line (A) be the line on the surface of the metal reinforcement layer 1 opposite to the wiring structure layer 2. Let line (B) be the line that is the surface of the wiring structure layer 2 side in the metal reinforcement layer 1. The shape of the opening 1a has two side lines, and the intersection point of one of the two side lines 1aa with line (A) is called intersection point (a), and the intersection point of the other side line 1aa with line (B) is called intersection point (b). Let the line connecting intersection point (a) and intersection point (b) be line segment (C). When the line (B) is divided into two halves, with the intersection point (b) as the starting point and the line on the opposite side of the opening 1a being defined as a half-line (BH), Let angle (α) be the angle between the ray (BH) and the line segment (C).

[0049] Next, we will describe an example of the wiring layer structure. Figure 9A is a schematic diagram of one embodiment of a wiring circuit board. The wiring circuit board 100 shown in Figure 9A has the same structure as the wiring circuit boards shown in Figures 1A and 1B. An example of the structure of region X in the wiring circuit board 100 shown in Figure 9A is shown in Figures 9B to 9E. In the structural example of region X shown in Figure 9B, the shape of the surface 22a of the wiring layer 22 on the side opposite the through-hole of the insulating layer 21 is flat. In the structural example of region X shown in Figure 9C, the shape of the surface 22a of the wiring layer 22 on the side opposite the through-hole of the insulating layer 21 is wave-shaped. In the example of the region X structure shown in Figure 9D, the shape of the surface 22a of the wiring layer 22 on the side opposite the through-hole of the insulating layer 21 is concave. In the structural example of region X shown in Figure 9E, the shape of the surface 22a of the wiring layer 22 on the side opposite the through-hole of the insulating layer 21 is convex. These shapes can be adjusted, for example, by the conditions for forming the wiring layer 22 to fill the through-holes in the insulating layer 22. In particular, when forming the wiring layer 22 to fill the through-holes in the insulating layer 21 by plating, these shapes can be adjusted according to the plating conditions, such as the components of the plating, the concentration of the plating solution, and the growth rate of the plating. Furthermore, the non-flat shape of the surface 22a of the wiring layer 22, as shown in Figures 9C to 9E, is sometimes referred to as a recess.

[0050] Next, an embodiment in which a semiconductor chip is connected to a wiring circuit board will be described. Figure 10 is a schematic cross-sectional view of an embodiment in which a semiconductor chip 200 is connected to a wiring circuit board 100. The wiring circuit board 100 is the wiring circuit board shown in Figures 1A and 1B. The semiconductor chip 200 comprises a semiconductor chip body 201 and solder balls 202. A semiconductor chip 200 is placed in an opening 1a of the metal reinforcement layer 1 of the wiring circuit board 100, and a portion of the wiring layer 22 that fills the through-hole of the insulating layer 21 is electrically connected to the solder ball 202. The shape of the opening 1a of the wiring circuit board 100 is not particularly limited, as long as the angle (α) is less than 90°, and the semiconductor chip body 201 does not come into contact with the metal portion of the metal reinforcement layer 1.

[0051] For example, a wiring circuit board 100 to which a semiconductor chip 200 is connected is mounted on another larger substrate, and then sealed with a sealing resin composition to protect the semiconductor chip and the wiring circuit board. During this sealing, if the angle (α) is less than 90°, the sealing resin composition can penetrate into the gap between the edge of the opening 1a of the metal reinforcement layer 1 and the semiconductor chip, thereby suppressing the retention of voids within the opening 1a of the metal reinforcement layer 1 after sealing.

[0052] (Semiconductor package) The semiconductor package of the present invention includes the wiring circuit board of the present invention. A semiconductor package includes, for example, a semiconductor chip connected to a wiring circuit board. A semiconductor package includes, for example, a sealing resin that encloses a semiconductor chip. Examples of semiconductor packages include FC-CSP (Flip Chip-Chip Scale Package), MIS-BGA (Molded Interconnect Substrate-Ball Grid Array) packages, ETS-BGA (Embedded Trace Substrate-Ball Grid Array) packages, Fan-out WLP (Wafer Level Package), Fan-in WLP, Fan-out PLP (Panel Level Package), Fan-in PLP, FC-BGA (Flip Chip-Ball Grid Array), and high-end 2.5D and 3D packages.

[0053] (electronic equipment) The electronic device of the present invention includes the semiconductor package of the present invention. Examples of electronic devices are not particularly limited and include, for example, ICT infrastructure equipment such as servers, routers, supercomputers, mainframes, and workstations; antennas such as GPS antennas, base station antennas, millimeter-wave antennas, and RFID antennas; communication devices such as mobile phones, smartphones, PHS phones, PDAs, and tablet terminals; digital devices such as personal computers, televisions, digital cameras, digital video cameras, POS terminals, wearable devices, and digital media players; in-vehicle electronic devices such as electronic control systems, in-vehicle communication equipment, car navigation equipment, millimeter-wave radar, and in-vehicle camera modules; semiconductor testing equipment, high-frequency measuring equipment, etc. [Explanation of Symbols]

[0054] 1. Metal reinforcement layer 1a opening 1b Second opening 1c Third opening 1d Fourth opening 1e Fifth opening 2 wiring structure layer 21 Insulating layer 21a Through hole 22 wiring layer 23 Second insulating layer 23a Through hole 24 Second wiring layer 25 Third insulating layer 25a through hole 26 Third wiring layer 27. Fourth insulating layer 27a Through hole 28 Fourth wiring layer 29. Fifth insulating layer 100 Wiring Circuit Boards 200 semiconductor chips 201 Semiconductor chip body 202 Handa Ball

Claims

1. A wiring circuit board having a wiring structure layer having an insulating layer and a wiring layer, and a metal reinforcing layer in contact with one surface of the wiring structure layer, The surface of the metal reinforcement layer opposite to the wiring structure layer is exposed. The metal reinforcement layer has an opening for connecting the semiconductor chip to the wiring circuit board, the opening having a penetration in the thickness direction of the metal reinforcement layer. In the cross-section of the metal reinforcement layer in the thickness direction and including the opening, Let line (A) be the line on the surface of the metal reinforcement layer opposite to the wiring structure layer. Let the line that is the surface of the metal reinforcement layer on the wiring structure layer side be defined as line (B). The shape of the opening has two side lines, and the intersection point of one of the two side lines with line (A) is defined as intersection point (a), and the intersection point of the other side line with line (B) is defined as intersection point (b). Let the line connecting intersection point (a) and intersection point (b) be line segment (C). Of the lines (B) mentioned above, when the line on the opposite side from the opening, starting from the intersection point (b), is defined as a half-line (BH), The angle (α) between the half-line (BH) and the line segment (C) is less than 90°. Wiring circuit board.

2. The wiring circuit board according to claim 1, wherein the angle (α) is 45° or more and less than 90°.

3. The wiring circuit board according to claim 1, wherein the metal reinforcing layer has a second opening that penetrates the metal reinforcing layer in the thickness direction, in addition to the opening.

4. The metal reinforcing layer has, in addition to the opening, a second opening and a third opening that penetrate the metal reinforcing layer in the thickness direction. In any cross-section (X) in the thickness direction of the metal reinforcement layer, the second opening and the third opening are formed so as to sandwich the opening. A wiring circuit board according to claim 1.

5. The wiring circuit board according to claim 4, wherein in a cross-section of the metal reinforcing layer in the thickness direction, and in a cross-section (Y) perpendicular to the cross-section (X), the metal reinforcing layer does not have an opening that penetrates the metal reinforcing layer in the thickness direction.

6. The metal reinforcing layer further has a fourth opening that penetrates the metal reinforcing layer in the thickness direction, The cross-section (Y) in the thickness direction of the metal reinforcement layer is formed such that the cross-section (Y) perpendicular to the cross-section (X) includes the fourth opening. The wiring circuit board according to claim 4.

7. The wiring circuit board according to claim 1, wherein the wiring structure layer has an insulating layer other than the insulating layer and a wiring layer other than the wiring layer within the opening of the metal reinforcement layer.

8. The wiring circuit board according to claim 1, wherein the wiring structure layer does not have an insulating layer other than the insulating layer and a wiring layer other than the wiring layer within the opening of the metal reinforcement layer.

9. A semiconductor package comprising a wiring circuit board according to any one of claims 1 to 8.

10. An electronic device comprising the semiconductor package described in claim 9.

11. A method for manufacturing a wiring circuit board according to any one of claims 1 to 8, The process includes forming the opening in the metal reinforcing layer that penetrates in the thickness direction of the metal reinforcing layer, The step of forming the opening includes forming the opening such that the angle (α) is less than 90°. A method for manufacturing a wiring circuit board.

12. The method for manufacturing a wiring circuit board according to claim 11, wherein the step of forming the opening includes forming the opening by wet etching such that the angle (α) is less than 90°.

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