Rewiring substrate and method of manufacturing the same

Abstract

According to the present invention, a redistribution board used to electrically connect a first electrical element and a second electrical element comprises: a first insulating layer (2) including first and second main surfaces facing opposite each other; a first terminal portion formed to be exposed on the first main surface of the first insulating layer (2); 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 including an opening; and a second insulating layer formed on the inner surface of the opening of the metal support.

Description

Technology Field

[0001] The present invention relates to a redistribution substrate and a method for manufacturing the same. Background Technology

[0002] For example, a redistribution substrate is sometimes inserted between a semiconductor chip and a package substrate. The redistribution substrate serves to convert the pitch between, for instance, the fine pattern of the semiconductor chip and the coarse pattern of the package substrate. The redistribution substrate is also called an interposer substrate, and a redistribution substrate composed of organic resin is also called an organic interposer substrate.

[0003] The semiconductor device described in Patent Document 1 has a wiring circuit layer. The wiring circuit layer functions as a redistribution layer. The wiring circuit layer includes an insulating layer and a conductor layer. The conductor layer is formed inside the insulating layer. One conductive path extends from the conductor layer to one main surface, and another conductive path extends from the conductor layer to the other main surface. At the tip of one conductive path, a connecting conductor portion exposed on one main surface is provided, and at the tip of the other conductive path, a connecting conductor portion exposed on the other main surface is provided.

[0004] In the manufacture of the semiconductor device of Patent Document 1, a wiring circuit layer is formed on a metallic support substrate. In this state, a semiconductor element is stacked and connected on one side of the wiring circuit layer. After that, the metallic support substrate is peeled off from the wiring circuit layer.

[0005] A semiconductor device mounting substrate described in Patent Document 2 includes a wiring structure film composed of an insulating layer and a wiring layer. Additionally, the semiconductor device mounting substrate has a first electrode pattern on one side of the wiring structure film and a second electrode pattern on the opposite side. A metal support is provided on the opposite side of the wiring structure film. Patent Document 1 describes an example in which the metal support is selectively removed so that the second electrode pattern is exposed. In this case, a semiconductor device is placed in the opening of the metal support and connected to the second electrode pattern. Accordingly, one semiconductor device can be placed on one side of the wiring structure film and another semiconductor device can be placed on the opposite side of the wiring structure film, and the one semiconductor device and the other semiconductor device can be electrically connected through the wiring structure film. Prior art literature

[0006] Japanese Published Patent Application No. 2010-232524 Japanese Published Patent Application No. 2003-347459 The problem to be solved

[0007] In the semiconductor device described in Patent Document 1, bending is prone to occur in the insulating layer. Furthermore, in the substrate for mounting the semiconductor device described in Patent Document 2, in order to place the semiconductor element within the opening of the metal support, it is necessary to make the dimensions of the opening larger than the dimensions of the semiconductor element. Consequently, the effect of suppressing bending by the metal support is reduced. On the other hand, it is considered to place the semiconductor element outside the opening while making the dimensions of the opening smaller. However, the reliability of the connection between the semiconductor element and the second electrode pattern is reduced.

[0008] The objective of the present invention is to provide a redistribution board capable of ensuring connection reliability while suppressing the occurrence of warping, and a method for manufacturing the same. means of solving the problem

[0009] (1) A redistribution board according to one aspect of the present invention is a redistribution board used to electrically connect a first electrical element and a second electrical element, and comprises a first insulating layer including first and second main surfaces facing opposite each other, 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 including 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 direction perpendicular to the first main surface of the first insulating layer, the first terminal portion is provided to be electrically connected to the first electrical element through or within the opening, and the second terminal portion is provided to be electrically connected to the second electrical element.

[0010] In his redistribution board, a metal support including an opening is formed on a first main surface of a first insulating layer. A first terminal is exposed on the first main surface of the first insulating layer, and a second terminal is exposed on the second main surface of the first insulating layer, and the first terminal and the second terminal are connected by a conductor layer within the second insulating layer. Since the opening is arranged to overlap with the first terminal in a first direction, the first terminal is exposed within the opening.

[0011] When using the redistribution board, a first electrical element is electrically connected to a first terminal through or within an opening, and a second electrical element is electrically connected to a second terminal through an opening. Accordingly, the first electrical element and the second electrical element are electrically connected by the redistribution board.

[0012] According to the above configuration, a metal support is formed on the first main surface of the first insulating layer. Accordingly, the occurrence of bending of the first insulating layer is suppressed. In addition, a second insulating layer is provided on the inner surface of the opening of the metal support. Accordingly, when connecting the first terminal part and the first electrical element within the opening by means of a connecting material without increasing the size of the opening, the occurrence of contact between the connecting material within the opening and the metal support can be suppressed. As a result of these, it is possible to ensure the connection reliability of the redistribution board while suppressing the occurrence of bending of the first insulating layer.

[0013] (2) In the redistribution board, the metal support includes a third main surface, and the second insulating layer may be further formed on at least a portion of the third main surface of the metal support.

[0014] In this case, when the first terminal part and the first electrical element are connected by interposing a connecting material, the electrical connection between the first electrical element and the third main surface of the metal support is suppressed.

[0015] (3) In the redistribution board, the second insulating layer may be formed on the third main surface and also at the edge of the opening.

[0016] In this case, when connecting the first terminal part and the first electrical element by interposing a connecting material, the occurrence of contact between the connecting material extending from within the opening and the edge portion of the opening of the metal support can be suppressed. Accordingly, the first terminal part and the first electrical element can be connected using a sufficient amount of connecting material. As a result, connection reliability is improved.

[0017] (4) The first terminal part includes a plurality of first terminal parts, and the second terminal part includes a plurality of second terminal parts corresponding to the plurality of first terminal parts, and the conductor layer includes a plurality of conductor layers that each connect the plurality of first terminal parts and the plurality of second terminal parts corresponding to each other, and the opening may be arranged to overlap with each of the plurality of first terminal parts in the first direction.

[0018] According to this configuration, when the first and second electrical elements each include a plurality of electrode pads, it is possible to ensure connection reliability between the plurality of electrode pads of the first electrical element and the plurality of electrode pads of the second electrical element while suppressing the occurrence of bending of the first insulating layer.

[0019] (5) The openings are provided to correspond to each of the first terminals and include a plurality of openings that overlap each of the first terminals in the first direction, and the plurality of openings are formed independently so as to be separated from each other, and the second insulating layer may be formed on the inner surface of each of the plurality of openings.

[0020] According to this configuration, each of the plurality of first terminal sections is exposed within an independent opening. In this case, since a second insulating layer is formed on the inner surface of each opening, the plurality of second terminal sections are insulated from one another. Accordingly, the reliability of the connection between the plurality of terminal sections and the first electrical element is improved.

[0021] (6) The opening is provided in common to at least two of the first terminals among the plurality of first terminals and also includes an opening in common to at least two of the first terminals in the first direction, and the second insulating layer may be formed on the inner surface of the common opening.

[0022] In this case, the formation of the opening and the second insulating layer becomes easier. Additionally, it becomes possible to connect multiple first terminal sections to each other within the opening.

[0023] (7) The minimum distance between multiple first terminals may be greater than the minimum distance between multiple second terminals.

[0024] In this case, a plurality of openings that overlap each of a plurality of terminal portions can be easily formed in the metal support, and a second insulating layer can be easily formed on the inner surface of each opening. Accordingly, a redistribution board used when the pitch of a plurality of electrode pads of a first electrical element is larger than the pitch of a plurality of electrode pads of a second electrical element can be easily manufactured.

[0025] (8) The thickness of the second insulating layer may be 1 µm or more and 10 µm or less.

[0026] In this case, the size of the opening can be increased, and the occurrence of contact between the first terminal and the metal support can be suppressed.

[0027] (9) The coefficient of linear expansion of the metal support at 25°C to 200°C may be 0.5 to 20 ppm.

[0028] In this case, the expansion and contraction of the metal support due to temperature changes is extremely small. Therefore, the occurrence of warping of the redistribution board due to temperature changes is suppressed.

[0029] (10) The thickness of the metal support may be 10㎛ or more and 100㎛ or less.

[0030] In this case, an opening can be easily formed in the metal support while suppressing the occurrence of bending of the second insulating layer. In addition, if the thickness of the metal support is set relatively large within this range, it becomes possible to improve the heat dissipation efficiency of the metal support. As a result, the heat dissipation performance of the redistribution board is improved.

[0031] (11) The metal support may be formed by a metal including one selected from iron, nickel and chromium, or by an alloy including multiple elements selected from iron, nickel and chromium.

[0032] In this case, it becomes possible to form a metal support using inexpensive materials. Consequently, it becomes possible to suppress the increase in the cost of the redistribution board.

[0033] (12) The first insulating layer may include a porous insulating material in at least some of its area.

[0034] In this case, the dielectric constant of a portion of the first insulating layer within the redistribution board can be reduced. Accordingly, it becomes possible to adjust the high-frequency characteristics of the redistribution board.

[0035] (13) A method for manufacturing a redistribution board according to another aspect of the present invention is a method for manufacturing a redistribution board used to electrically connect a first electrical element and a second electrical element, comprising a process of forming a stacked structure of a metal support and a redistribution structure layer, a process of forming an opening in the metal support, and a process of forming a second insulating layer on the inner surface of the opening. The process of forming the redistribution structure layer comprises forming a first insulating layer including first and second main surfaces facing opposite each other, forming a first terminal portion electrically connectable to the first electrical element so as to be exposed on the first main surface of the first insulating layer, forming a second terminal portion electrically connectable to the second electrical element so as to be exposed on the second main surface of the first insulating layer, and forming a conductor layer connecting the first terminal portion and the second terminal portion within the first insulating layer. The process of forming the opening comprises forming an opening in the first insulating layer so as to allow the first terminal portion to be electrically connected to the first electrical element through the opening or within the opening.

[0036] According to the above configuration, a laminated structure of a metal support and a redistribution structure layer is formed. Accordingly, the occurrence of bending of the first insulating layer is suppressed. In addition, a second insulating layer is formed on the inner surface of the opening of the metal support. Accordingly, without increasing the size of the opening, when connecting the first terminal part and the first electrical element within the opening through a connecting material, the occurrence of contact between the connecting material within the opening and the metal support can be suppressed. As a result of these, it becomes possible to manufacture a redistribution board with secured connection reliability while suppressing the occurrence of bending of the first insulating layer. Effects of the invention

[0037] According to the present invention, a redistribution board capable of ensuring connection reliability while suppressing the occurrence of bending can be provided. Brief explanation of the drawing

[0038] FIG. 1 is a schematic cross-sectional view showing the configuration of a redistribution board according to one embodiment. Figure 2 is a schematic plan view of the redistribution board of Figure 1. Figure 3 is a schematic bottom view of the redistribution board of Figure 1. FIG. 4 is a schematic cross-sectional view illustrating a first manufacturing method of a redistribution board. FIG. 5 is a schematic cross-sectional view illustrating a first manufacturing method of a redistribution board. FIG. 6 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution board. FIG. 7 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution board. FIG. 8 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution board. FIG. 9 is a schematic cross-sectional view illustrating a first manufacturing method of a redistribution board. FIG. 10 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution substrate. FIG. 11 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution board. FIG. 12 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution board. FIG. 13 is a schematic cross-sectional view illustrating a first method of manufacturing a redistribution board. FIG. 14 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 15 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 16 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 17 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 18 is a schematic cross-sectional view illustrating a second method of manufacturing a redistribution board. FIG. 19 is a schematic cross-sectional view illustrating a second method of manufacturing a redistribution board. FIG. 20 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 21 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 22 is a schematic cross-sectional view illustrating a second manufacturing method of a redistribution board. FIG. 23 is a schematic cross-sectional view showing the configuration of a redistribution board according to another embodiment. FIG. 24 is a schematic cross-sectional view showing the configuration of a redistribution board according to another embodiment. FIG. 25 is a schematic cross-sectional view showing the configuration of a redistribution board according to another embodiment. FIG. 26 is a schematic cross-sectional view showing the configuration of a redistribution board according to another embodiment. FIG. 27 is a schematic cross-sectional view showing the configuration of a redistribution board according to another embodiment. Specific details for implementing the invention

[0039] Hereinafter, a redistribution substrate and a method for manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0040] (1) Configuration of a redistribution board according to one embodiment

[0041] FIG. 1 is a schematic cross-sectional view showing the configuration of a redistribution board according to one embodiment. FIG. 2 is a schematic plan view of the redistribution board of FIG. 1. FIG. 3 is a schematic bottom view of the redistribution board of FIG. 1. FIG. 1 shows the AA line cross-section of FIG. 2 and FIG. 3. As shown in FIG. 1, the redistribution board (100) comprises a metal support (1), a redistribution structure layer (RS), and a second insulating layer (5).

[0042] In FIG. 1, the metal support (1) is formed by a metal including, for example, one selected from iron, nickel, and chromium, or by an alloy including multiple elements selected from iron, nickel, and chromium. In this embodiment, the metal support (1) is formed in a plate shape by stainless steel. In FIG. 1, the upper surface of the metal support (1) is referred to as the upper surface, and the lower surface is referred to as the lower surface. Additionally, the metal support (1) may be made of 42 alloy or Inver alloy, etc. When an Inver alloy is used for the metal support (1), it becomes possible to adjust the coefficient of linear expansion of the metal support (1) in response to changes in the nickel (Ni) composition within the Inver alloy. In this case, it becomes possible to easily suppress the occurrence of warping of the redistribution structure layer (RS) described later. The metal support (1) preferably has a thickness of 10 μm or more and 100 μm or less, and more preferably has a thickness of 20 μm or more and 50 μm or less. In this embodiment, the metal support (1) has a thickness of 50 μm. Additionally, when the thickness of the metal support (1) is large, the heat dissipation efficiency of the metal support (1) is improved; therefore, when heat dissipation is important, it is desirable to set the thickness of the metal support (1) to a value close to 100 μm. It is desirable that the coefficient of linear expansion of the metal support (1) from 25°C to 200°C be 0.5 ppm or more and 20 ppm or less. Accordingly, expansion and contraction of the metal support (1) due to temperature changes is suppressed. A plurality of openings (11a, 11b) are formed in the metal support (1). The plurality of openings (11a, 11b) are spaced apart from each other and penetrate from the upper surface to the lower surface of the metal support (1).

[0043] In this embodiment, a second insulating layer (5) is formed to cover the lower surface of the metal support (1) and the inner surface of the openings (11a, 11b). In this embodiment, the second insulating layer (5) is formed by a photosensitive polyimide resin. Additionally, the second insulating layer (5) may be formed by other synthetic resins such as acrylic resin, polyethernitrile resin, polyethersulfone resin, epoxy resin, polyethylene terephthalate resin, polyethylene naphthalate resin, or polyvinyl chloride resin. Furthermore, it is preferable that the second insulating layer (5) has a thickness of 1 μm or more and 10 μm or less, and it is preferable that it has a thickness of 2 μm or more and 5 μm or less. In this embodiment, the thickness of the second insulating layer (5) is 3 μm.

[0044] A redistribution structure layer (RS) is formed on the upper surface of a metal support (1). The redistribution structure layer (RS) includes a first insulating layer (2). In this embodiment, the lower surface of the first insulating layer (2) is called the first main surface (21), and the upper surface of the first insulating layer (2) is called the second main surface (22). In this embodiment, the first insulating layer (2) is formed by a photosensitive polyimide resin. Additionally, the first insulating layer (2) may be formed by other synthetic resins such as acrylic resin, polyethernitrile resin, polyethersulfone resin, epoxy resin, polyethylene terephthalate resin, polyethylene naphthalate resin, or polyvinyl chloride resin.

[0045] The first insulating layer (2) may have a laminated structure of multiple insulating layers. In this embodiment, the first insulating layer (2) has a laminated structure of multiple insulating layers (2A, 2B, 2C). The multiple insulating layers (2A, 2B, 2C) are laminated and integrated in this order on the upper surface of the metal support (1). The thickness of each insulating layer (2A, 2B, 2C) is, for example, 2 μm or more and 10 μm or less, and preferably 3 μm or more and 5 μm or less.

[0046] The redistribution structure layer (RS) further includes a plurality of conductor layers (41a to 43a, 41b to 43b) and a plurality of terminal portions (31a, 31b, 32a, 32b). In this embodiment, the terminal portions (31a, 31b) have a laminated structure of a nickel film and a gold plating film. Specifically, a nickel film is formed on the surface of the conductor layers (41a, 41b), and a gold plating film is formed on the nickel film. Additionally, the terminal portions (31a, 31b) may have a structure in which a gold plating film is formed on the conductor layers (41a, 41b) without including a nickel film. In this embodiment, the conductor layers (41a to 43a, 41b to 43b) are formed of copper. In addition, the conductor layers (41a to 43a, 41b to 43b) may be formed by a metal including one selected from copper, gold, silver, platinum, lead, tin, nickel, cobalt, indium, rhodium, chromium, tungsten, and ruthenium, or by an alloy including multiple elements.

[0047] A terminal portion (31a) is provided within an insulating layer (2A) so as to be exposed from the first surface (21) within an opening (11a) of a metal support (1). Likewise, a terminal portion (31b) is provided within an insulating layer (2A) so as to be exposed from the first surface (21) within an opening (11b) of a metal support (1). Among the terminal portions (31a, 31b), the film exposed within the opening (11a, 11b) is preferably formed by a material having a resistivity lower than that of the conductor layers (41a-43a, 41b-43b).

[0048] The conductor layers (41a, 41b) are provided within the insulating layer (2A) so as to be laminated to the terminal portions (31a, 31b), respectively. In this case, the terminal portions (31a, 31b) overlap the openings (11a, 11b), respectively, when viewed from the bottom (when the lower surface of the metal support (1) is viewed vertically from below). Hereinafter, the lower surface of the metal support (1) is referred to as the third main surface (12).

[0049] The conductor layers (42a, 42b) are arranged to be connected to the conductor layers (41a, 41b) respectively within the insulating layer (2B).

[0050] Conductor layers (43a, 43b) are provided within the insulating layer (2C) so as to be connected to each conductor layer (42a, 42b). Terminal portions (32a, 32b) are provided within the insulating layer (2C) so as to be laminated on each conductor layer (43a, 43b) while being exposed from the second main surface (22).

[0051] In this embodiment, the terminal portions (32a, 32b) have a laminated structure of a nickel film and a gold plating film. Specifically, a nickel film is formed on the surface of the conductor layer (43a, 43b), and a gold plating film is formed on the nickel film. Additionally, the terminal portions (32a, 32b) may have a structure in which a gold plating film is formed on the conductor layer (43a, 43b) without including a nickel film. It is preferable that the film exposed from the second main surface (22) of the terminal portions (32a, 32b) be formed by a material having a resistivity lower than that of the conductor layer (41a-43a, 41b-43b). In this embodiment, the distance between the plurality of terminal portions (31a, 31b) is greater than the distance between the plurality of terminal portions (32a, 32b).

[0052] According to the above configuration, a terminal portion (31a) exposed from the first main surface (21) of the first insulating layer (2) and a terminal portion (32a) exposed from the second main surface (22) are electrically connected. Likewise, a terminal portion (31b) exposed from the first main surface (21) of the first insulating layer (2) and a terminal portion (32b) exposed from the second main surface (22) are electrically connected.

[0053] A printed circuit board (200) is disposed on the lower side of a metal support (1). The printed circuit board (200) includes electrode pads (201a, 201b). A semiconductor device (300) is disposed on the upper side of a redistribution structure layer (RS). The semiconductor device (300) includes electrode pads (301a, 301b). In this example, the distance between the electrode pads (201a, 201b) of the printed circuit board (200) is greater than the distance between the electrode pads (301a, 301b) of the semiconductor device (300).

[0054] Solder (400a, 400b) is placed in each of the openings (11a, 11b) of the metal support (1) to connect the terminal portions (31a, 31b) and the printed circuit board (200). In this state, the terminal portions (31a, 31b) exposed from the first main surface (21) of the first insulating layer (2) and the electrode pads (201a, 201b) of the printed circuit board (200) are connected to each other via the solder (400a, 400b).

[0055] Solder (450a, 450b) is respectively placed on terminal portions (32a, 32b) exposed from the second main surface (22) of the first insulating layer (2). In this state, the terminal portions (32a, 32b) and the electrode pads (301a, 301b) of the semiconductor device (300) are respectively connected by interposing the solder (450a, 450b).

[0056] Accordingly, the printed circuit board (200) and the semiconductor device (300) are electrically connected via the redistribution board (100).

[0057] In this embodiment, as shown in FIG. 2, a plurality of terminal portions (32) including terminal portions (32a, 32b) of FIG. 1 are formed in the first insulating layer (2) so as to be exposed from the second main surface (22). The configuration of the other terminal portions (32) is the same as the configuration of the terminal portions (32a, 32b) of FIG. 1. Also, as shown in FIG. 3, a plurality of openings (11) including openings (11a, 11b) are formed in the metal support (1), and a plurality of terminal portions (31) including terminal portions (31a, 31b) are formed within the plurality of openings (11) so as to be exposed from the first main surface (21). The configuration of the other openings (11) and the other terminal portions (31) is the same as the configuration of the openings (11a, 11b) and terminal portions (31a, 31b). In this embodiment, the distance between the plurality of terminal parts (31) is greater than the distance between the plurality of terminal parts (32).

[0058] (2) First manufacturing method of the redistribution board (100)

[0059] FIGS. 4 to 13 are schematic cross-sectional views for explaining a first manufacturing method of a redistribution substrate (100). In this embodiment, the redistribution substrate (100) is manufactured by a roll-to-roll method.

[0060] First, a roll (hereinafter referred to as the extrusion roll) on which a long metal support (1) is wound is prepared, and the metal support (1) is extruded from the prepared extrusion roll. The metal support (1) extruded from the extrusion roll is wound onto another roll (hereinafter referred to as the winding roll). In FIG. 4, a cross-section of a portion of the metal support (1) extruded from the extrusion roll is shown. According to the roll-to-roll method, as the long metal support (1) moves in the long direction, the following processing is performed sequentially on each region of the metal support (1).

[0061] As shown in FIG. 5, an insulating layer (2A) is formed by a photosensitive polyimide resin in a predetermined area of ​​the upper surface of the metal support (1). In this embodiment, openings (2a, 2b) are formed in the insulating layer (2A).

[0062] Next, as shown in FIG. 6, terminal portions (31a, 31b) are formed respectively within the openings (2a, 2b) of the insulating layer (2A) by, for example, electrolytic plating. In this embodiment, the terminal portions (31a, 31b) are formed by forming a gold plating film and a nickel film in sequence. Additionally, a conductor layer (41a, 41b) is formed on the terminal portions (31a, 31b) within the openings (2a, 2b) by electrolytic copper plating. Accordingly, the terminal portions (31a, 31b) and the conductor layer (41a, 41b) are electrically connected. In FIG. 6, the plating resist is omitted from the illustration.

[0063] Next, as shown in FIG. 7, an insulating layer (2B) is formed on the insulating layer (2A). In the insulating layer (2B), openings (2c, 2d) are formed so that the conductor layers (41a, 41b) are exposed, respectively. The openings (2c, 2d) are spaced apart from each other and are also independent.

[0064] In this state, as shown in FIG. 8, a conductor layer (42a, 42b) is formed on the insulating layer (2A) and conductor layer (41a, 41b) within the opening (2c, 2d), for example by electrolytic copper plating. Accordingly, the conductor layer (41a, 41b) within the insulating layer (2A) and the conductor layer (42a, 42b) within the insulating layer (2B) are connected. In FIG. 8, the plating resist and the seed layer are omitted from the illustration.

[0065] Next, as shown in FIG. 9, an insulating layer (2C) is formed on the insulating layer (2B). In the insulating layer (2C), openings (2e, 2f) are formed so that a portion of the upper surface of the conductor layers (42a, 42b) is exposed. The openings (2e, 2f) are spaced apart from each other and are also independent. The insulating layers (2A, 2B, 2C) are integrated as a first insulating layer (2).

[0066] Next, as shown in FIG. 10, a conductor layer (43a, 43b) is formed on the conductor layer (42a, 42b) within the opening (2e, 2f), for example, by electrolytic copper plating. Accordingly, the conductor layer (42a, 42b) within the insulating layer (2B) and the conductor layer (43a, 43b) within the insulating layer (2C) are electrically connected. Additionally, on the conductor layer (43a, 43b) within the opening (2e, 2f), terminal portions (32a, 32b) are each formed so as to be exposed from the second main surface (22), for example, by electrolytic plating. In the terminal portions (32a, 32b), a nickel film is formed on the surface of the conductor layer (43a), and a gold plating film is formed on the nickel film.

[0067] In this way, a redistribution structure layer (RS) is formed on the metal support (1). Accordingly, the terminal portions (31a, 31b) of the first main surface (21) of the first insulating layer (2) and the terminal portions (32a, 32b) of the second main surface (22) are electrically connected through a conductor layer (41a~43a, 41b~43b).

[0068] Next, as shown in FIG. 11, an etching resist pattern (ER) is formed by applying an etching resist to the third main surface (12) of the metal support (1), followed by exposure, development, and curing treatments. The etching resist pattern (ER) is formed to include an opening that surrounds each of the terminal portions (31a, 31b) when viewed through the bottom (when the first main surface (21) of the first insulating layer (2) is viewed vertically from below through the metal support (1). In this state, the metal support (1) is etched. Wet etching or dry etching, etc., are used as the etching method.

[0069] Accordingly, as shown in FIG. 12, openings (11a, 11b) corresponding to terminal portions (31a, 31b) of the first insulating layer (2) are formed. In addition, in FIG. 12 and FIG. 13, the inner surface of the openings (11a, 11b) is shown perpendicular to the first main surface (21) of the first insulating layer (2), but the inner surface of the openings (11a, 11b) may be inclined with respect to the first main surface (21) of the first insulating layer (2). For example, the diameter of the lower end of the openings (11a, 11b) may be larger than the diameter of the upper end. When viewed from the bottom, the terminal portions (31a, 31b) overlap with the openings (11a, 11b) and are also exposed within the openings (11a, 11b).

[0070] Afterwards, as shown in FIG. 13, a second insulating layer (5) comprising a photosensitive polyimide resin is formed to cover the inner surface of the openings (11a, 11b) and the third surface (12) of the metal support (1), excluding the first surface (21) of the first insulating layer (2) within the openings (11a, 11b). In this case, for example, the second insulating layer (5) is formed on the surface of the metal support (1) while a photoresist film is formed on the first surface (21) including the terminal portions (31a, 31b) within the openings (11a, 11b). Afterwards, the portion of the second insulating layer (5) on the photoresist film within the openings (11a, 11b) is removed together with the photoresist film.

[0071] (3) Second manufacturing method of the redistribution board (100)

[0072] FIGS. 14 to 22 are schematic cross-sectional views for explaining a second manufacturing method of a redistribution substrate (100).

[0073] First, in FIG. 14, a cross-section of a portion of a metal support (1) extruded from an extrusion roll is shown, similar to the first manufacturing method. Also, as shown in FIG. 14, an insulating layer (2A) is formed by a photosensitive polyimide resin in a predetermined area of ​​the upper surface of the metal support (1). In this embodiment, openings (2a, 2b) are formed in the insulating layer (2A).

[0074] Next, a laminated film (layered in the order of chrome and copper) is formed by sputtering on the insulating layer (2A) and within the concave portions (2a, 2b) (not shown). In this state, as shown in FIG. 15, a resist film (RF) is formed in a predetermined area on the insulating layer (2A). Then, as shown in FIG. 16, a conductor layer (41a, 41b) is formed by electrolytic copper plating within the openings (2a, 2b) of the insulating layer (2A), and a conductor layer (42a, 42b) is formed by electrolytic copper plating in the area where the resist film (RF) on the insulating layer (2A) is not formed. In the present manufacturing method, the conductor layer (41a) and the conductor layer (42a) are formed integrally, and the conductor layer (41b) and the conductor layer (42b) are formed integrally. After that, the resist film (RF) is removed, and the laminated film (not shown) remaining on the insulating layer (2A) is removed by etching in the order of copper and chromium.

[0075] Next, as shown in FIG. 17, an insulating layer (2B, 2C) is integrally formed on the insulating layer (2A) and the conductor layer (42a, 42b) by means of a photosensitive polyimide resin. An opening (2e, 2f) is formed in the insulating layer (2C) so that the conductor layer (42a, 42b) is exposed. The openings (2e, 2f) are spaced apart from each other and are also independent. The insulating layer (2A, 2B, 2C) is integrated as a first insulating layer (2).

[0076] In this state, as shown in FIG. 18, a conductor layer (43a, 43b) is formed by electrolytic copper plating on the conductor layer (42a, 42b) within the opening (2e, 2f). Accordingly, the conductor layer (42a, 42b) within the insulating layer (2B) and the conductor layer (43a, 43b) within the insulating layer (2C) are electrically connected.

[0077] Next, as shown in FIG. 19, an etching resist pattern (ER) is formed by applying an etching resist onto the third main surface (12) of the metal support (1), followed by exposure, development, and curing treatments. Additionally, curing treatment may not be performed during the formation of the etching resist pattern (ER). The etching resist pattern (ER) is formed to include an opening that surrounds each of the terminal portions (31a, 31b) when viewed through the bottom (when the first main surface (21) of the first insulating layer (2) is viewed vertically from below through the metal support (1)). In this state, the metal support (1) is etched. Wet etching or dry etching, etc., may be used as the etching method.

[0078] Accordingly, as shown in FIG. 20, openings (11a, 11b) corresponding to the conductor layers (41a, 41b) exposed to the first main surface (21) are formed. Additionally, in FIG. 20 and FIG. 21, the inner surface of the openings (11a, 11b) is shown perpendicular to the first main surface (21) of the first insulating layer (2), but the inner surface of the openings (11a, 11b) may be inclined with respect to the first main surface (21) of the first insulating layer (2). For example, the diameter of the lower end of the openings (11a, 11b) may be larger than the diameter of the upper end.

[0079] Afterwards, as shown in FIG. 21, a second insulating layer (5) comprising a photosensitive polyimide resin is formed to cover the inner surface of the openings (11a, 11b) of the metal support (1) and the third main surface (12). In this case, for example, the second insulating layer (5) is formed on the surface of the metal support (1) while a photoresist film is formed on the first main surface (21) including terminal portions (31a, 31b) within the openings (11a, 11b). Afterwards, the portion of the second insulating layer (5) on the photoresist film within the openings (11a, 11b) is removed together with the photoresist film.

[0080] Next, as shown in FIG. 22, terminal portions (31a, 31b) are respectively formed on the surface of a conductor layer (41a, 41b) exposed from the first main surface (21) within the opening (11a, 11b) of the metal support (1) by electroplating, and terminal portions (32a, 32b) are respectively formed on the surface of a conductor layer (43a, 43b) exposed from the second main surface (22). In this case, after a nickel film is formed on the surface of the conductor layer (41a, 41b, 43a, 43b), a gold plating film is formed on the surface of the nickel film.

[0081] In this way, a redistribution structure layer (RS) is formed on the metal support (1). Accordingly, the terminal portions (31a, 31b) of the first main surface (21) of the first insulating layer (2) and the terminal portions (32a, 32b) of the second main surface (22) are electrically connected through a conductor layer (41a~43a, 41b~43b).

[0082] (4) Effects of the embodiment

[0083] According to the redistribution board (100) of the present embodiment, a metal support (1) is formed on the first main surface (21) of the first insulating layer (2). Accordingly, the occurrence of bending of the first insulating layer (2) is suppressed. In addition, a second insulating layer (5) is provided on the inner surface of the openings (11a, 11b) of the metal support (1). Accordingly, when connecting the terminal portions (31a, 31b) and the printed circuit board (200) by means of solder (400a, 400b) without increasing the size of the openings (11a, 11b), contact between the solder (400a, 400b) inside the openings (11a, 11b) and the metal support (1) can be suppressed. As a result of these, it is possible to secure connection reliability of the redistribution board (100) while suppressing the occurrence of bending of the first insulating layer (2).

[0084] In addition, in this embodiment, the second insulating layer (5) is also formed on the third main surface (12) of the metal support (1). In this case, when the terminal portions (31a, 31b) and the printed circuit board (200) are connected via solder (400a, 400b), the electrical connection between the printed circuit board (200) and the third main surface (12) of the metal support (1) is suppressed.

[0085] Furthermore, in this embodiment, a plurality of terminal portions (31) (see FIG. 3) including terminal portions (31a, 31b) are formed on the first main surface (21) of the first insulating layer (2) of the redistribution structure layer (RS), and a plurality of terminal portions (32) (see FIG. 2) including terminal portions (32a, 32b) are formed on the second main surface (22). Additionally, a plurality of openings (11) including openings (11a, 11b) are independently provided so as to overlap with the terminal portions (31a, 31b (31)) respectively when viewed as a bottom surface. Accordingly, when the printed circuit board (200) and the semiconductor element (300) each include a plurality of electrode pads, it becomes possible to secure connection reliability between the plurality of electrode pads of the printed circuit board (200) and the plurality of electrode pads of the second electrical element while suppressing the occurrence of bending of the first insulating layer (2).

[0086] In addition, in this embodiment, the minimum distance among the distances between the plurality of terminal portions (31a, 31b (31)) is greater than the minimum distance among the distances between the plurality of second terminal portions (32a, 32b (32)). In this case, a plurality of openings (11a, 11b (11)) that overlap each of the plurality of terminal portions (31a, 31b (31)) can be easily formed in the metal support (1), and a second insulating layer (5) can be easily formed on the inner surface of each opening (11a, 11b (11)). Accordingly, a redistribution board (100) used when the pitch of the plurality of electrode pads of the printed circuit board (200) is greater than the pitch of the plurality of electrode pads of the semiconductor device (300) can be easily manufactured.

[0087] In addition, in this embodiment, if the second insulating layer (5) has a thickness of 1 μm or more and 10 μm or less, the size of the openings (11a, 11b) is not increased, and contact between the terminal portions (31a, 31b) and the metal support (1) can be suppressed.

[0088] In addition, in this embodiment, when the coefficient of linear expansion of the metal support (1) at 25°C to 200°C is set to 0.5 to 20 ppm, the expansion and contraction of the metal support (1) due to temperature change is extremely small. Therefore, the occurrence of warping of the redistribution substrate (100) due to temperature change is suppressed.

[0089] In addition, in this embodiment, when the thickness of the metal support (1) is 10 μm or more and 100 μm or less, the increase in weight of the redistribution board (100) can be suppressed while suppressing the occurrence of bending of the first insulating layer (2). In addition, by making the thickness of the metal support (1) large within the above range, heat dissipation of the redistribution board (100) can be secured.

[0090] In addition, in this embodiment, the metal support (1) is formed by a metal including one selected from iron, nickel, and chromium, or by an alloy including multiple elements selected from iron, nickel, and chromium, so it is possible to form the metal support (1) with an inexpensive material. Accordingly, it is possible to suppress the increase in cost of the redistribution substrate (100).

[0091] (5) Other embodiments

[0092] FIGS. 23 to 27 are schematic cross-sectional views showing the configuration of a redistribution substrate (100) according to other embodiments.

[0093] (5-1) In the redistribution board (100) of the above embodiment, openings (11a, 11b) spaced apart from each other are formed independently in the metal support (1) corresponding to each terminal part (31a, 31b) so that the terminal part (31a, 31b) of the first insulating layer (2) is exposed on the first main surface (21), but the present invention is not limited thereto. As shown in FIG. 23, a single opening (11c) common to a plurality of terminal parts (31a, 31b) may be formed in the metal support (1) so that the terminal part (31a, 31b) of the first insulating layer (2) is exposed on the first main surface (21). In this case, since the bending of the redistribution board (100) is suppressed and a second insulating layer (5) is formed on the surface of the metal support (1), it becomes possible to easily connect the terminal portions (31a, 31b) and the electrode pads (201a, 201b) of the printed circuit board (200). Additionally, it becomes possible to connect multiple terminal portions (31a, 31b) to each other within the opening (11c). Furthermore, according to the configuration of FIG. 23, it becomes possible to place the semiconductor device (300) of FIG. 1 within the opening (11c). In this case, the terminal portions (31a, 31b) of the redistribution board (100) and the electrode pads (301a, 301b) of the semiconductor device (300) are each electrically connected within the opening (11c).

[0094] (5-2) In the redistribution board (100) of the above embodiment, a second insulating layer (5) is formed to cover the entire third main surface (12) of the metal support (1), but the present invention is not limited thereto. As shown in FIG. 24, the second insulating layer (5) does not need to be formed on a part of the third main surface (12). In this case, it is possible to reduce the cost of forming the second insulating layer (5). Also, heat is easily released from the area of ​​the third main surface (12) where the second insulating layer (5) is not formed. Accordingly, the heat dissipation of the redistribution board (100) is improved. In addition, for example, the second insulating layer (5) may be formed only on the edge portions of the openings (11a, 11b) of the third main surface (12) of the metal support (1), and the second insulating layer (5) may not be formed on the central portion of the third main surface (12). Additionally, the edge portion of the opening (11a, 11b) in the third main surface (12) is, for example, an area having a width of 10 μm or more from the peripheral edge of the opening (11a, 11b) on the third main surface (12). Also, the width from the peripheral edge of the opening (11a, 11b) in the edge portion of the opening (11a, 11b) in the third main surface (12) may be appropriately determined according to the size of the redistribution substrate (100).

[0095] (5-3) In the redistribution substrate (100) of the above embodiment, the second insulating layer (5) is formed to have a thickness of 1 μm or more and 10 μm or less, but the present invention is not limited thereto. As shown in FIG. 25, the second insulating layer (5) may have a thickness greater than, for example, the thickness of the insulating layer (2A). Also, the second insulating layer (5) may have a thickness greater than that of the insulating layer (2B) and the insulating layer (2C). Additionally, the second insulating layer (5) may be formed to have a thickness greater than or equal to the thickness of the first insulating layer (2). In this case, since the second insulating layer (5) having a relatively large thickness is formed on the metal support (1), it becomes possible to further suppress the bending of the first insulating layer (2) and improve connection reliability.

[0096] (5-4) In the redistribution board (100) of the above embodiment, the insulating layers (2A, 2B, 2C) are formed from the same material, but the present invention is not limited thereto. As shown in FIG. 26, the insulating layer (2A) may be formed from a porous insulator (e.g., porous polyimide resin). In this case, the dielectric constant of the insulating layer (2A) can be reduced. Accordingly, it becomes possible to adjust the high-frequency characteristics of the redistribution board (100). Likewise, as shown in FIG. 27, the insulating layer (2C) may be formed from a porous insulator (e.g., porous polyimide resin). In this case, the dielectric constant of the insulating layer (2C) can be reduced. Accordingly, the high-frequency characteristics of the redistribution board (100) can be adjusted. Additionally, the insulating layer (2B) may be formed by a porous insulator (e.g., a porous polyimide resin). Additionally, the second layer (2B) and the third layer (2C) may be formed by a porous insulator (e.g., a porous polyimide resin).

[0097] (5-5) In the redistribution board (100) of the above embodiment and other embodiments, two sets of terminal portions (31a, 31b, 32a, 32b), conductor layers (41a, 42a, 43a, 41b, 42b, 43b), and openings (11a, 11b) are provided on the redistribution board (100), but the present invention is not limited thereto. For example, three or more sets of terminal portions, conductor layers, and openings may be provided on the redistribution board (100) in correspondence with the number of electrode pads of the printed circuit board (200) and the number of electrode pads of the semiconductor device. In addition, one set of terminal portions, conductor layers, and openings may be provided on the redistribution board (100).

[0098] (5-6) In the above embodiment and other embodiments of the redistribution board (100), electrode pads (201a, 201b) of a printed circuit board (200) are respectively connected to terminal portions (31a, 31b) of the first insulating layer (2), and electrode pads (301a, 301b) of a semiconductor device (300) are respectively connected to terminal portions (32a, 32b) of the first insulating layer (2), but the present invention is not limited thereto. Electrode pads (301a, 301b) of a semiconductor device (300) may be respectively connected to terminal portions (31a, 31b) of the first insulating layer (2), and electrode pads (201a, 201b) of a printed circuit board (200) may be respectively connected to terminal portions (32a, 32b) of the first insulating layer (2).

[0099] (5-7) In the above embodiment, the redistribution board (100) is connected to the printed circuit board (200) as a first electrical element and is also connected to the semiconductor element (300) as a second electrical element, but the present invention is not limited thereto. The first electrical element may be a semiconductor element, another electronic element or an electronic circuit, and the second electrical element may be a printed circuit board, another electronic element or an electronic circuit.

[0100] (5-8) The dimensions and materials of each component of the redistribution substrate according to the present invention are not limited to the dimensions and materials of the above embodiments.

[0101] (5-9) In the above embodiment, the first insulating layer (2) is formed from three insulating layers (2A, 2B, 2C), but the present invention is not limited thereto. The first insulating layer (2) may be a single insulating layer or may be formed from a different number of insulating layers.

[0102] (6) Correspondence between each component of the claim and each part of the embodiment

[0103] Hereinafter, examples of correspondence between each component of the claim and each element of the embodiment will be described. In the above embodiment, terminal portions (31a, 31b) are examples of first terminal portions, terminal portions (32a, 32b) are examples of second terminal portions, printed circuit board (200) is an example of first electrical element, and semiconductor device (300) is an example of second electrical element.

Claims

Claim 1 A redistribution board used to electrically connect a first electrical element and a second electrical element, comprising: a first insulating layer including first and second main surfaces facing opposite each other; 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 including 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 direction perpendicular to the first main surface of the first insulating layer, and the first terminal portion is a film formed on the surface of the conductor layer by a material having a resistivity lower than that of the conductor layer, and is provided by being laminated on the conductor layer along the thickness direction of the first insulating layer within the opening formed on the first main surface of the first insulating layer, and within the opening of the metal support A redistribution board that is exposed from the first main surface of the first insulating layer and is configured to be electrically connected to the first electrical element through the opening, and the second terminal portion is configured to be electrically connected to the second electrical element. Claim 2 A redistribution substrate according to claim 1, wherein the metal support comprises a third main surface, and the second insulating layer is further formed on at least a portion of the third main surface of the metal support. Claim 3 In paragraph 2, the second insulating layer is a redistribution substrate formed on the third main surface and also at the edge of the opening. Claim 4 A redistribution board according to any one of claims 1 to 3, wherein the first terminal portion comprises a plurality of first terminal portions, the second terminal portion comprises a plurality of second terminal portions corresponding to the plurality of first terminal portions, the conductor layer comprises a plurality of conductor layers connecting the plurality of first terminal portions corresponding to each other and the plurality of second terminal portions, and the opening is provided to overlap the plurality of first terminal portions in the first direction. Claim 5 A redistribution board according to claim 4, wherein the opening is provided to correspond to each of the plurality of first terminal portions and also includes a plurality of openings that overlap each of the plurality of first terminal portions in the first direction, the plurality of openings are formed independently so as to be separated from each other, and the second insulating layer is formed on the inner surface of each of the plurality of openings. Claim 6 A redistribution board according to claim 4, wherein the opening is provided in common to at least two of the plurality of first terminal parts and also includes an opening in common to the at least two first terminal parts in the first direction, and the second insulating layer is formed on the inner surface of the common opening. Claim 7 A redistribution board according to claim 4, wherein the minimum distance among the distances between the plurality of first terminal portions is greater than the minimum distance among the distances between the plurality of second terminal portions. Claim 8 A redistribution substrate according to any one of claims 1 to 3, wherein the thickness of the second insulating layer is 1 μm or more and 10 μm or less. Claim 9 A redistribution board used for electrically connecting a first electrical element and a second electrical element, comprising: a first insulating layer including first and second main surfaces facing opposite each other; 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 including 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 direction perpendicular to the first main surface of the first insulating layer, wherein the first terminal portion is provided to be electrically connected to the first electrical element through or within the opening, wherein the second terminal portion is provided to be electrically connected to the second electrical element, and wherein the coefficient of linear expansion of the metal support at 25°C to 200°C A redistribution substrate having a concentration of 0.5 to 20 ppm. Claim 10 A redistribution substrate according to any one of claims 1 to 3, wherein the thickness of the metal support is 10㎛ or more and 100㎛ or less. Claim 11 A redistribution board used for electrically connecting a first electrical element and a second electrical element, comprising: a first insulating layer including first and second main surfaces facing opposite each other; 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 including 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 direction perpendicular to the first main surface of the first insulating layer, wherein the first terminal portion is provided to be electrically connected to the first electrical element through or within the opening, and wherein the second terminal portion is provided to be electrically connected to the second electrical element, and wherein the metal support is made of a metal comprising one selected from iron, nickel, and chromium A redistribution substrate formed by, or formed by, an alloy comprising a plurality of elements selected from iron, nickel, and chromium. Claim 12 A redistribution substrate according to any one of claims 1 to 3, wherein the first insulating layer comprises a porous insulator in at least a portion of the area. Claim 13 A method for manufacturing a redistribution board used to electrically connect a first electrical element and a second electrical element, comprising: a process of forming a laminated structure of a metal support and a redistribution structure layer; a process of forming an opening in the metal support; and a process of forming a second insulating layer on the inner surface of the opening. The process of forming the redistribution structure layer comprises: forming a first insulating layer including first and second main surfaces facing opposite each other; forming a first terminal portion electrically connectable to the first electrical element so as to be exposed on the first main surface of the first insulating layer; forming a second terminal portion electrically connectable to the second electrical element so as to be exposed on the second main surface of the first insulating layer; forming a conductor layer connecting the first terminal portion and the second terminal portion within the first insulating layer; forming an opening on the first main surface of the first insulating layer; and forming the first terminal portion, which is a film formed by a material having a lower resistivity than the conductor layer, on the surface of the conductor layer and the conductor layer within the opening of the first insulating layer, wherein the thickness of the first insulating layer A method for manufacturing a redistribution board, comprising forming by stacking along a direction, wherein the process of forming the opening comprises forming the opening in the metal support such that the first terminal portion is exposed from the first main surface of the first insulating layer within the opening, and the first terminal portion can be electrically connected to the first electrical element through the opening.

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