Wiring circuit board

Abstract

The wiring circuit board (X1) of the present invention comprises a metal support substrate (10), an insulating layer (20), and a conductor layer (30) in this order in the thickness direction (D). The conductor layer (30) includes a terminal portion (E) and a tail portion (T) extending from said terminal portion (E). The terminal portion (E) has a via portion (32) that penetrates the insulating layer (20) in the thickness direction (D) and is connected to the metal support substrate (10). The tail portion (T) has a width in a direction perpendicular to the extension direction of said tail portion (T) that is different from the width of said terminal portion (E), and also has a base portion (33) connected to the terminal portion (E) and a via portion (34) that penetrates the insulating layer (20) in the thickness direction (D) and is connected to the metal support substrate (10).

Description

Technology Field

[0001] The present invention relates to a wiring circuit board. Background Technology

[0002] A wiring circuit board is known to have a metal support substrate, an insulating layer on the metal support substrate, and a wiring pattern on the insulating layer. In the wiring circuit board, for the sake of high-density wiring, a ground terminal is provided that is electrically connected to the metal support substrate and has, for example, a pad-on-via structure. Such a wiring circuit board is described, for example, in Patent Document 1 below. Prior art literature

[0003] Japanese Patent Publication No. 2014-157641 The problem to be solved

[0004] As shown in FIG. 15, the wiring circuit board described in Patent Document 1 has a metal support substrate (1), an insulating layer (2), and a terminal portion (3). The insulating layer (2) has an opening (2a) that penetrates the insulating layer (2) in the thickness direction. The terminal portion (3) includes a pad portion (4) disposed on the insulating layer (2) and a via portion (5) disposed in the opening (2a) and connected to the metal support substrate (1) (the pad portion (4) and the via portion (5) are connected). That is, the terminal portion (3) has a pad-on-via structure and is electrically connected to the metal support substrate (1), and functions as a ground terminal. Such a terminal portion (3) is formed, for example, by the deposition of a conductive material on the insulating layer (2) having the opening (2a) and subsequent patterning.

[0005] In such a wiring circuit board, in order to make the ground connection in the terminal portion (3) low resistance, for example, it is necessary to increase the diameter (via diameter) of the via portion (5). However, the terminal portion (3) has a recess (3a) on the exposed surface. The larger the via diameter, the larger the recess (3a). When a solder bump (6) as a terminal of an external component is bonded to the terminal portion (3), the larger the recess (3a), the easier it is for a void (G) to form between the terminal portion (3) and the solder bump (6). The formation of a void (G) is undesirable as it causes poor connection between the terminal portion (3) and the solder bump (6).

[0006] The present invention provides a wiring circuit board suitable for high-density wiring, and at the same time, suitable for realizing good connectivity to external component terminals and low-resistance ground connection in the terminal section. means of solving the problem

[0007] The present invention [1] comprises a metal support substrate, an insulating layer, and a conductor layer in this order in the thickness direction, wherein the conductor layer includes a terminal portion and a tail portion extending from said terminal portion, said terminal portion has a first via portion that penetrates the insulating layer in the thickness direction and is connected to said metal support substrate, said tail portion has a width different from the width of said terminal portion in a direction perpendicular to the extension direction of said tail portion, said terminal portion has a base portion connected to said terminal portion and a second via portion that penetrates the insulating layer in the thickness direction and is connected to said metal support substrate.

[0008] In the wiring circuit board of the present invention, as described above, the terminal portion has a first via portion connected to a metal support substrate, and furthermore, a tail portion extends from the terminal portion and has a second via portion connected to the metal support substrate. That is, in the wiring circuit board, the terminal portion having a via-on-pad (VOP) structure is electrically connected to the metal support substrate through the first via portion within the VOP structure, and additionally is electrically connected to the metal support substrate through the second via portion outside the VOP structure. Such a configuration is suitable for reducing the resistance of the electrical connection between the terminal portion and the metal support substrate while suppressing the enlargement of each of the first via portion and the second via portion.

[0009] The above configuration, in which the terminal portion has a VOP structure and is also suitable for suppressing the large diameter of the second via portion, is suitable for securing a wiring formation area in a wiring circuit board and thus is suitable for promoting high-density wiring. The above configuration, in which the terminal portion is suitable for suppressing the large diameter of the concave portion on the exposed surface of the terminal portion, is suitable for suppressing the large diameter of the concave portion and thus is suitable for securing good connectivity of the terminal portion to external component terminals. The above configuration, in which the electrical connection between the terminal portion and the metal support substrate is suitable for realizing a low-resistance ground connection through the metal support substrate in the terminal portion.

[0010] The present invention [2] includes a wiring circuit board described in [1], wherein the connection area of ​​the second via portion to the metal support substrate is larger than the connection area of ​​the first via portion to the metal support substrate.

[0011] Such a wiring circuit board is suitable for reducing the resistance of the electrical connection between the terminal portion and the metal support substrate while suppressing the enlargement of the first via portion.

[0012] The present invention [3] includes a wiring circuit board described in [1] or [2], wherein the tail portion has a plurality of the second via portions.

[0013] Such a wiring circuit board is suitable for reducing the resistance of the electrical connection between the terminal portion and the metal support substrate while suppressing the enlargement of each of the first via portion and the second via portion.

[0014] The present invention [4] includes a wiring circuit board described in [3], wherein the sum of the connection areas of the plurality of second vias for the metal support substrate is greater than the connection area of ​​the first vias for the metal support substrate.

[0015] Such a wiring circuit board is suitable for suppressing the large diameter of the first via portion while promoting low resistance of the electrical connection between the terminal portion and the metal support substrate.

[0016] The present invention [5] includes a wiring circuit board described in any one of [1] to [4], wherein the terminal portion comprises a first conductor layer on the insulating layer side and a second conductor layer on the first conductor layer.

[0017] It is desirable for the terminal section to have a two-layer structure from the perspective of securing the strength of the terminal section. It is also desirable for the terminal section to have a two-layer structure from the perspective of securing good connectivity of the terminal section by suppressing the size of the concave portion on the surface of the terminal section.

[0018] The present invention [6] includes a wiring circuit board described in any one of [1] to [5], wherein the conductor layer has two terminal portions and the tail portion extends from one terminal portion to the other terminal portion.

[0019] This configuration (a configuration in which the tail line extending from the terminal section is common to two terminal sections) is suitable for securing a wiring formation area in a wiring circuit board, and thus is suitable for promoting high-density wiring. Brief explanation of the drawing

[0020] FIG. 1 is a partial plan view of a first embodiment of a wiring circuit board of the present invention. Figure 2 is a cross-sectional view along line II-II of Figure 1. FIG. 3 illustrates an example of a method for manufacturing a wiring circuit board as illustrated in FIG. 1. FIG. 3 (A) illustrates a preparation process, FIG. 3 (B) illustrates a base insulating layer formation process, FIG. 3 (C) illustrates a conductor layer formation process, and FIG. 3 (D) illustrates a cover insulating layer formation process. FIG. 4 is a partial plan view of one variant of a wiring circuit board of the first embodiment. In this variant, the tail line portion has a plurality of second via portions. Figure 5 is a cross-sectional view along line V-V of Figure 4. FIG. 6 is a partial plan view of another variation of the wiring circuit board of the first embodiment. In this variation, the pattern shape of the tail line portion is different from that of the first embodiment. FIG. 7 is a partial plan view of another variation of the wiring circuit board of the first embodiment. In this variation, the wiring circuit board has two terminal portions connected at the tail portion. Figure 8 is a cross-sectional view along line VIII-VIII of Figure 7. FIG. 9 illustrates a variation in which the terminal portion has a plurality of first via portions. In the variation shown in FIG. 9 (A), the terminal portion has a plurality of via portions arranged in a line together with the second via portion of the tail portion. In the variation shown in FIG. 9 (B), the terminal portion has a first via portion at each of the four corners when viewed from a planar perspective. FIG. 10 is a partial plan view of a second embodiment of the wiring circuit board of the present invention. FIG. 11 is a cross-sectional view along the line XI-XI of FIG. 10. FIG. 12 illustrates some of the processes in the method for manufacturing a wiring circuit board illustrated in FIG. 10. FIG. 12 (A) illustrates the process of forming a first conductor layer, FIG. 12 (B) illustrates the process of forming a second conductor layer, and FIG. 12 (C) illustrates the process of forming a cover insulating layer. FIG. 13 is a partial plan view of one variation of a wiring circuit board of the second embodiment. In this variation, two terminal portions connected at the tail portion are provided. FIG. 14 is a cross-sectional view along the line XⅣ-XⅣ of FIG. 13. FIG. 15 is a partial cross-sectional view of a conventional wiring circuit board. Specific details for implementing the invention

[0021] As shown in FIGS. 1 and 2, a wiring circuit board (X1) as a first embodiment of the wiring circuit board of the present invention comprises a metal support substrate (10), an insulating layer (20) as a base insulating layer, a conductor layer (30), and an insulating layer (40) as a cover insulating layer (not shown in FIG. 1) in this order facing one side of the thickness direction (D). The wiring circuit board (X1) is widened in a direction orthogonal to the thickness direction (D) (plane direction) and has a shape as seen from a predetermined plane.

[0022] The metal support substrate (10) is a substrate for ensuring the strength of the wiring circuit board (X1). Examples of materials for the metal support substrate (10) include stainless steel, copper, copper alloy, aluminum, nickel, titanium, and 42 alloy. Examples of stainless steel include SUS 304 based on the AISI (American Institute of Steel and Iron) standard. In terms of the strength of the metal support substrate (10), the metal support substrate (10) preferably comprises at least one material selected from the group consisting of stainless steel, copper alloy, aluminum, nickel, and titanium, and more preferably consists of at least one material selected from the group consisting of stainless steel, copper alloy, aluminum, nickel, and titanium. In terms of the compatibility of strength and conductivity of the metal support substrate (10), the metal support substrate (10) is preferably made of a copper alloy. The thickness of the metal support substrate (10) is, for example, 15 μm or more. The thickness of the metal support substrate (10) is, for example, 500 μm or less, preferably 250 μm or less.

[0023] The insulating layer (20) is disposed on one side in the thickness direction (D) of the metal support substrate (10). In this embodiment, the insulating layer (20) is disposed on one side in the thickness direction (D) of the metal support substrate (10). As the material of the insulating layer (20), examples include resin materials such as polyimide, polyethernitrile, polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, and polyvinyl chloride (same resin materials may also be used as the material of the insulating layer (40) described later). The thickness of the insulating layer (20) is preferably 1 μm or more, more preferably 3 μm or more. The thickness of the insulating layer (20) is preferably 35 μm or less, more preferably 15 μm or less.

[0024] The insulating layer (20) has an opening (21) and an opening (22) that penetrate the insulating layer (20) in the thickness direction (D). The openings (21, 22) are positioned between the metal support substrate (10) and the conductor layer (30). The openings (21, 22) are positioned at intervals along the length direction of the conductor layer (30) (specifically, the length direction of the later pad portion (31)).

[0025] The opening (21) has, for example, a roughly circular shape when viewed from a planar view. The opening (21) has an opening end (21a) on one side in the thickness direction (D) and an opening end (21b) on the other side in the thickness direction (D). Additionally, the opening (21) has an inner wall surface (21c) between the opening end (21a) and the opening end (21b). In this embodiment, the inner wall surface (21c) is inclined so that the portion closer to the metal support substrate (10) is positioned inward. That is, the inner wall surface (21c) is inclined so that the opening cross-sectional area of ​​the opening (21) becomes smaller the portion closer to the metal support substrate (10). On the side of the opening end (21b), the opening diameter of the opening (21) follows the diameter of the later via portion (32), for example, 10 μm to 200 μm.

[0026] The opening (22) has, for example, a roughly circular shape when viewed from a planar view. The opening (22) has an opening end (22a) on one side in the thickness direction (D) and an opening end (22b) on the other side in the thickness direction (D). Additionally, the opening (22) has an inner wall surface (22c) between the opening end (22a) and the opening end (22b). In this embodiment, the inner wall surface (22c) is inclined so that the portion closer to the metal support substrate (10) is positioned inward. That is, the inner wall surface (22c) is inclined so that the opening cross-sectional area of ​​the opening (22) becomes smaller the portion closer to the metal support substrate (10). On the side of the opening end (22b), the opening diameter of the opening (22) is, for example, 20 μm to 1000 μm, depending on the diameter of the later via portion (34).

[0027] The conductor layer (30) is arranged continuously on one side in the thickness direction (D) of the insulating layer (20), on the inner wall surface (21c, 22c) of the openings (21, 22), and on the metal support substrate (10) facing each of the openings (21, 22). Examples of materials for the conductor layer (30) include copper, nickel, gold, and alloys thereof, and preferably copper is used. The thickness of the conductor layer (30) is, for example, 3 μm or more, and preferably 5 μm or more. The thickness of the conductor layer (30) is, for example, 50 μm or less, and preferably 30 μm or less.

[0028] The conductor layer (30) includes a terminal portion (E), a tail portion (T) extending from the terminal portion (E), and wiring (not shown) (in FIG. 2, the boundary between the terminal portion (E) and the tail portion (T) is shown as a dashed line). The wiring circuit board (X1) has at least one terminal portion (E) having a tail portion (T).

[0029] The terminal portion (E) is a ground terminal and has a pad portion (31) and a via portion (32) (first via portion).

[0030] The pad portion (31) is disposed on the insulating layer (20). The shape of the pad portion (31) as viewed from a plane may be, for example, a circle, a square, and a circular rectangle. Squares may be squares and rectangles. Circular rectangles may be circular squares and circular rectangles (an example is shown where the shape of the pad portion (31) as viewed from a plane is a circular rectangle). The length (L1) (length in the longitudinal direction of the pad portion (31)) shown in FIG. 1 for the pad portion (31) is, for example, 10 μm to 600 μm. The width (L2) (length in the direction perpendicular to the longitudinal direction) shown in FIG. 1 for the pad portion (31) is, for example, 10 μm to 600 μm. The area of ​​the pad portion (31) (area viewed from a plane as shown in FIG. 1) is, for example, 100 μm. 2 to 360,000㎛ 2 am.

[0031] A via portion (32) is disposed in an opening (21) of an insulating layer (20) (indicated by a dashed line in FIG. 1). Specifically, the via portion (32) penetrates the insulating layer (20) in the thickness direction (D) and is connected to a metal support substrate (10). The via portion (32) has a periphery side (32a) and an end (32b) connected to the metal support substrate (10). The terminal portion (E) has a cross-sectional concave shape near the location where the via portion (32) is formed.

[0032] In this embodiment, the perimeter side (32a) is inclined so that the portion closer to the metal support substrate (10) is positioned inward. That is, the perimeter side (32a) is inclined so that the cross-sectional area of ​​the via portion (32) becomes smaller the portion closer to the metal support substrate (10).

[0033] The diameter (R1) of the end portion (32b) (the diameter of the end portion on the metal support substrate (10) side in the via portion (32)) is preferably 10 μm or more, more preferably 20 μm or more, from the perspective of reducing the contact resistance of the via portion (32) to the metal support substrate (10). From the perspective of suppressing the size of the concave portion (C) on the surface of the pad portion (31) to ensure good connectivity of the terminal portion (E) (connectivity with the terminal of an external component), the diameter (R1) is preferably 200 μm or less, more preferably 150 μm or less.

[0034] The connection area (S1) of the via portion (32) to the metal support substrate (10) (projected area in the thickness direction (D) of the end portion (32b)) is preferably 70 μm in terms of reducing the connection resistance of the via portion (32) to the metal support substrate (10). 2 Above, more preferably 150㎛ 2 Ideally, more preferably 300㎛ 2 That is all. In order to ensure good connectivity of the terminal portion (E) by suppressing the size of the concave portion (C) on the surface of the pad portion (31), the connection area (S1) is preferably 40,000 μm 2 Below, more preferably 22,000 μm 2It is as follows.

[0035] In this embodiment, the tail line portion (T) has a shape viewed from a plane that extends linearly in the direction of extension from the terminal portion (E). The length (L3) of the tail line portion (T) in the direction of extension is, for example, 100 μm to 10,000 μm. Preferably, the length (L3) is smaller than the length (L1) from the perspective of suppressing the size of the tail line portion (T) viewed from a plane. The smaller the tail line portion (T), the more suitable it is for securing a wiring formation area on the wiring circuit board (X1), and thus, it is suitable for promoting high-density wiring.

[0036] The tail section (T) has a base section (33) and a via section (34) (second via section).

[0037] The base portion (33) is connected to the terminal portion (E). The base portion (33) has a width (L4) in a direction perpendicular to the extension direction of the tail portion (T) from the terminal portion (E). The width (L4) is different from the width (L2) of the terminal portion (E). Preferably, the width (L4) is smaller than the width (L2) from the perspective of securing a wiring formation area and from the perspective of high-density wiring. The width (L4) of the base portion (33) is, for example, 50 μm to 600 μm. The ratio of the width (L4) to the width (L2) is, for example, 0.08 or more and less than 1.

[0038] The via portion (34) is disposed in the opening (22) of the insulating layer (20) (indicated by a dashed line in FIG. 1). Specifically, the via portion (34) penetrates the insulating layer (20) in the thickness direction (D) and is connected to the metal support substrate (10). The via portion (34) has a periphery side (34a) and an end (34b) connected to the metal support substrate (10). The terminal portion (E) has a cross-sectional concave shape near the location where the via portion (34) is formed.

[0039] In this embodiment, the perimeter side (34a) is inclined so that the portion closer to the metal support substrate (10) is positioned inward. That is, the perimeter side (34a) is inclined so that the cross-sectional area of ​​the via portion (34) becomes smaller the portion closer to the metal support substrate (10).

[0040] The diameter (R2) of the end portion (34b) (the diameter of the end portion on the metal support substrate (10) side in the via portion (34)) is preferably 20 μm or more, more preferably 30 μm or more, in terms of reducing the contact resistance of the via portion (34) to the metal support substrate (10). In terms of suppressing the size viewed from the plane of the tail portion (T), the diameter (R2) is preferably 1000 μm or less, more preferably 500 μm or less.

[0041] The connection area (S2) of the via portion (34) to the metal support substrate (10) (projected area in the thickness direction (D) of the end portion (34b)) is preferably 300 μm in terms of reducing the connection resistance of the via portion (34) to the metal support substrate (10). 2 Above, more preferably 700㎛ 2 That is all. In terms of controlling the size of the tail section (T), the connection area (S2) is preferably 1,000,000 μm 2 Below, more preferably 500,000 μm 2 Below, more preferably 250,000㎛ 2 The following applies. In order to suppress the large hardening of the via portion (32) and to promote low resistance of the electrical connection between the terminal portion (E) and the metal support substrate (10), the ratio of the connection area (S2) to the connection area (S1) is preferably 1.2 or more, more preferably 1.5 or more. The same ratio is, for example, 1500 or less.

[0042] The insulating layer (40) is positioned to cover a portion of the conductor layer (30) on one side of the thickness direction (D) of the insulating layer (20). In this embodiment, the insulating layer (40) is positioned to cover a portion of the tail line portion (T) and is positioned to cover the location where the via portion (34) is formed when viewed from a planar view. The thickness of the insulating layer (40) is, for example, 4 μm or more, preferably 6 μm or more. The thickness of the insulating layer (40) on the insulating layer (20) or on the tail line portion (T) is, for example, 60 μm or less, preferably 40 μm or less.

[0043] FIGS. 3 (A) to FIGS. 3 (D) illustrate an example of a method for manufacturing a wiring circuit board (X1). FIGS. 3 (A) to FIGS. 3 (D) illustrate the manufacturing method as a change in cross-section corresponding to FIG. 2.

[0044] In the present manufacturing method, first, a metal support substrate (10) is prepared as shown in (A) of FIG. 3 (preparation process). On one side of the metal support substrate (10) in the thickness direction (D) (the upper side in the drawing), an adhesion layer (not shown) for ensuring adhesion of the insulating layer (20) to the metal support substrate (10) may be formed in advance. That is, in this embodiment, a metal support substrate (10) having an adhesion layer on one side in the thickness direction (D) may be used.

[0045] The adhesion layer is a layer for ensuring adhesion of the insulating layer (20) to the metal support substrate (10). Examples of the adhesion layer include a film formed by a sputtering method (sputter film), a film formed by a plating method (plated film), and a film formed by a vacuum deposition method (vacuum deposition film). Examples of the materials of the adhesion layer include Cr, Ni, and Ti. The material of the adhesion layer may be an alloy comprising two or more metals selected from the group consisting of Cr, Ni, and Ti. Preferably, Cr is used as the material of the adhesion layer. The thickness of the adhesion layer is, for example, 1 nm or more, preferably 10 nm or more, and more preferably 20 nm or more. The thickness of the adhesion layer is, for example, 10,000 nm or less, preferably 1,000 nm or less, and more preferably 500 nm or less.

[0046] Next, as shown in (B) of FIG. 3, an insulating layer (20) is formed on one side of the metal support substrate (10) in the thickness direction (D) (base insulating layer formation process). In this process, for example, the insulating layer (20) is formed as follows. First, a solution (varnish) of a photosensitive resin is applied to the metal support substrate (10) to form a coating film. Next, this coating film is dried by heating. Next, the coating film is subjected to exposure treatment through a predetermined mask, subsequent development treatment, and then baking treatment as necessary. For example, an insulating layer (20) having openings (21, 22) can be formed on the metal support substrate (10) as described above. In each of the openings (21, 22), the metal support substrate (10) is exposed.

[0047] Next, as shown in (C) of FIG. 3, a conductor layer (30) is continuously formed on the insulating layer (20), on the inner wall surfaces (21c, 22c) of the openings (21, 22), and on the metal support substrate (10) exposed to each of the openings (21, 22) (conductor layer formation process). In this process, first, a seed layer (not shown) is formed, for example, by sputtering, on the insulating layer (20), on the inner wall surfaces (21c, 22c) of the openings (21, 22), and on the metal support substrate (10) exposed to each of the openings (21, 22). Examples of materials for the seed layer include Cr, Cu, Ni, Ti, and alloys thereof (the same applies to materials for the later seed layer). The seed layer may have a single-layer structure or a multi-layer structure of two or more layers. When the seed layer has a multilayer structure, the seed layer is composed, for example, of a chrome layer as a lower layer and a copper layer on top of the chrome layer. Next, a resist pattern is formed on the seed layer. The resist pattern has an opening with a shape corresponding to the pattern shape of the conductor layer (30). In forming the resist pattern, for example, a photosensitive resist film is attached to the seed layer to form a resist film, and then, on the resist film, an exposure treatment through a predetermined mask, a subsequent development treatment, and then a baking treatment are performed as necessary (the same applies to the formation of the resist pattern in the later stages). In forming the conductor layer (30), the above-mentioned metal is grown on the seed layer within the opening of the resist pattern by, for example, an electroplating method. Next, the resist pattern is removed by etching. Next, the portion exposed by the removal of the resist pattern in the seed layer is removed by etching. For example, as described above, a conductor layer (30) (terminal part (E), tail part (T), wiring) of a predetermined pattern can be formed.

[0048] Next, as shown in (D) of FIG. 3, an insulating layer (40) is formed on the insulating layer (20) to cover a portion of the conductor layer (30) (cover insulating layer formation process). In this process, the insulating layer (40) is formed, for example, as follows. First, a solution (varnish) of a photosensitive resin is applied to the insulating layer (40) and the conductor layer (30) to form a coating film. Next, this coating film is dried. Next, the coating film is subjected to exposure treatment through a predetermined mask, subsequent development treatment, and then, if necessary, baking treatment. For example, the insulating layer (40) can be formed as described above.

[0049] After that, if necessary, the shape of the metal support substrate (10) is processed by etching the metal support substrate (10).

[0050] In this way, a wiring circuit board (X1) can be manufactured.

[0051] In the wiring circuit board (X1), as described above, the terminal portion (E) has a via portion (32) connected to the metal support substrate (10), and a tail portion (T) extends from the terminal portion (E), and the tail portion (T) has a via portion (34) connected to the metal support substrate (10). That is, in the wiring circuit board (X1), the terminal portion (E) having a via-on-pad (VOP) structure is electrically connected to the metal support substrate (10) through the via portion (32) within the VOP structure, and additionally, is electrically connected to the metal support substrate (10) through the via portion (34) outside the VOP structure. Such a configuration is suitable for reducing the resistance of the electrical connection between the terminal portion (E) and the metal support substrate (10) while suppressing the enlargement of each of the via portion (32) and the via portion (34). Even if the interface between the metal support substrate (10) and each via portion (32, 34) has relatively high resistance, the above configuration makes it easy to achieve low resistance in the electrical connection between the terminal portion (E) and the metal support substrate (10) (for example, a Cr layer is provided as the adhesion layer, and a Cr film is provided on at least the metal support substrate (10) side of the seed layer, and even if the interface between the metal support substrate (10) and each via portion (32, 34) has relatively high resistance, the above configuration makes it easy to achieve low resistance in the electrical connection between the terminal portion (E) and the metal support substrate (10)).

[0052] The above configuration, in which the terminal portion (E) has a VOP structure and is also suitable for suppressing the large diameter of the via portion (34), is suitable for securing a wiring formation area in the wiring circuit board (X1) and thus is suitable for promoting high density of wiring. The above configuration, in which the above configuration, is suitable for suppressing the large diameter of the via portion (32), is suitable for suppressing the large diameter of the concave portion (C) on the exposed surface of the terminal portion (E) and thus is suitable for securing good connectivity of the terminal portion (E) to external component terminals. The above configuration, in which the above configuration, is suitable for low resistance of the electrical connection between the terminal portion (E) and the metal support substrate (10), is suitable for realizing a low-resistance ground connection through the metal support substrate (10) in the terminal portion (E).

[0053] As described above, the wiring circuit board (X1) is suitable for high-density wiring, and at the same time, in the terminal section (E), it is suitable for realizing good connectivity to external component terminals and low-resistance ground connection.

[0054] Additionally, in the wiring circuit board (X1), the configuration in which the terminal portion (E) has a via portion (32) and the tail portion (T) has a via portion (34) is preferred from the perspective of noise suppression of the signal wiring when the signal wiring is arranged along the terminal portion (E) and the tail portion (T) (the noise suppression effect is higher than in the case where there is no via portion (32) or no via portion (34)).

[0055] In the wiring circuit board (X1), as shown in FIGS. 4 and 5, the tail line portion (T) may have a plurality of via portions (34) (an example is shown in which the tail line portion (T) has three via portions (34)). In this variation, the plurality of via portions (34) are arranged in a row with spacing in the extension direction when viewed from the plane of the tail line portion (T). The distance between the via portions (34) is, for example, 35 μm to 1000 μm.

[0056] A configuration in which the tail section (T) has a plurality of via sections (34) is suitable for promoting low resistance in the electrical connection between the terminal section (E) and the metal support substrate (10) while suppressing the enlargement of the via sections (34). Preferably, in terms of this low resistance, the sum of the connection areas (S2) of the plurality of via sections (34) to the metal support substrate (10) is greater than the connection area (S1) of the via sections (32) of the terminal section (E). In terms of the low resistance, the ratio of the sum of the connection areas (S2) of the plurality of via sections (34) to the connection area (S1) of the via sections (32) is preferably 1.2 or more, more preferably 1.5 or more. The same ratio is, for example, 1500 or less. Suppression of the large diameter of the via (34) helps suppress the size of the tail section (T) when viewed from the plane, and thus helps to secure a wiring formation area in the wiring circuit board (X1) and promote high density of wiring.

[0057] In this modified example, the via portion (32) and a plurality of via portions (34) are arranged in a row. This configuration is desirable for the purpose of suppressing noise in the signal wiring when the signal wiring is arranged along the terminal portion (E) and the tail portion (T).

[0058] In the wiring circuit board (X1), the tail line portion (T) may have a shape other than a shape that extends straight from the terminal portion (E) when viewed from a planar view. For example, as shown in FIG. 6, the tail line portion (T) may have a first portion (Ta) that extends from the terminal portion (E) and a second portion (Tb) that extends in a direction intersecting the extension direction of the first portion (Ta). In the present variation, the tail line portion (T) has a plurality of via portions (34) in the second portion (Tb) (an example is shown where the tail line portion (T) has three via portions (34)). The tail line portion (T) is formed in a shape according to the wiring layout around the terminal portion (E).

[0059] In the wiring circuit board (X1), as shown in FIGS. 7 and 8, the conductor layer (30) may include two terminal sections (E) (terminal section (E1) and terminal section (E2)) connected by a tail section (T). In this modified example, the tail section (T) extends from one terminal section (E1) to the other terminal section (E2). That is, the tail section (T) extending from the terminal section (E) is common to the terminal section (E1) and the terminal section (E2). Such a configuration is suitable for securing a wiring formation area in the wiring circuit board (X1) and is therefore suitable for promoting high-density wiring.

[0060] In the wiring circuit board (X1), the terminal portion (E) may have a plurality of via portions (32) as shown in (A) and (B) of FIG. 9.

[0061] In the modified example illustrated in FIG. 9 (A), the terminal portion (E) has a plurality of via portions (32) arranged in a row together with the via portions (34) of the tail portion (T) (in FIG. 9 (A), the case in which the terminal portion (E) has two via portions (32) is illustrated as an example). Such a configuration is desirable in terms of noise suppression of the signal wiring when the signal wiring is arranged along the terminal portion (E) and the tail portion (T).

[0062] In the modified example illustrated in (B) of FIG. 9, the terminal portion (E) has via portions (32) at each of the four corners when viewed from a planar perspective. This configuration is desirable in terms of reducing the resistance of the electrical connection through the via portions (32) between the terminal portion (E) and the metal support substrate (10).

[0063] FIGS. 10 and 11 illustrate a wiring circuit board (X2) as a second embodiment of the wiring circuit board of the present invention. Similar to the wiring circuit board (X1), the wiring circuit board (X2) comprises a metal support substrate (10), an insulating layer (20) as a base insulating layer, a conductor layer (30), and an insulating layer (40) as a cover insulating layer (omitted in FIG. 10) in this order, facing one side in the thickness direction (D). The wiring circuit board (X2) differs from the wiring circuit board (X1) in that it additionally has a conductor layer (30A) on a part of the conductor layer (30) and has a terminal portion (E') instead of a terminal portion (E). Except for this, the wiring circuit board (X2) has the same configuration as the wiring circuit board (X1).

[0064] The terminal portion (E') includes a conductor layer (30) (first conductor layer) on the insulating layer (20) side and a conductor layer (30A) (second conductor layer) on the conductor layer (30), and has a two-layer structure of conductor layers (30, 30A). In addition, the terminal portion (E') has a pad portion (31') and a via portion (32) (first via portion). The terminal portion (E') is different from the terminal portion (E) in that it has a pad portion (31') instead of a pad portion (31).

[0065] The pad portion (31') includes the pad portion (31) described above and a conductor layer (30A) on the pad portion (31). The conductor layer (30A) has an outer shape that fits within the outer shape of the pad portion (31) when viewed from a planar view. As for the shape of the conductor layer (30A) viewed from a planar view, for example, the shape described above can be given as the shape viewed from the planar view of the pad portion (31) (an example is illustrated where the shape viewed from each planar view of the pad portion (31) and the conductor layer (30A) is a rectangular shape). As for the material of the conductor layer (30A), the material described above with respect to the conductor layer (30) can be given. The material of the conductor layer (30) and the material of the conductor layer (30A) are preferably the same, and more preferably copper. The materials of the conductor layers (30, 30A) may be different. The thickness of the conductor layer (30A) 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.

[0066] It is desirable for the pad portion (31') to have these two-layer structures in terms of securing the strength of the pad portion (31'). It is also desirable for the pad portion (31') to have two-layer structures in terms of securing good connectivity of the terminal portion (E') by suppressing the size of the concave portion (C) on the surface of the pad portion (31').

[0067] In the wiring circuit board (X2), a tail line portion (T) extends from such a terminal portion (E'). The wiring circuit board (X2) includes at least one terminal portion (E') having a tail line portion (T).

[0068] FIGS. 12 (A) to FIGS. 12 (C) illustrate an example of a method for manufacturing a wiring circuit board (X2). FIGS. 12 (A) to FIGS. 12 (C) illustrate the manufacturing method as a change in cross-section corresponding to FIG. 11.

[0069] In the present manufacturing method, first, a preparation process and a base insulating layer forming process are carried out as described above with reference to FIG. 3 (A) and FIG. 3 (B).

[0070] Next, as shown in (A) of FIG. 12, a conductor layer (30) is patterned on the insulating layer (20) (first conductor layer formation process). Specifically, it is the same as described above with reference to (C) of FIG. 3.

[0071] Next, as shown in (B) of FIG. 12, a conductor layer (30A) is formed on the conductor layer (30) (second conductor layer formation process). In this process, first, a seed layer (not shown) is formed, for example by sputtering, to cover the insulating layer (20) and the conductor layer (30, 30A). Next, a resist pattern is formed on the seed layer. The resist pattern has an opening with a shape corresponding to the pattern shape of the conductor layer (30A). Next, the metal described above is grown on the seed layer within the opening of the resist pattern by electroplating. Next, the resist pattern is removed by etching. Next, the portion exposed by the removal of the resist pattern in the seed layer is removed by etching. For example, the conductor layer (30A) can be formed on the conductor layer (30) in the manner described above.

[0072] Next, as shown in (C) of FIG. 12, an insulating layer (40) is formed on the insulating layer (20) to cover a portion of the conductor layer (30) (cover insulating layer formation process). Specifically, with reference to (D) of FIG. 3, it is as described above.

[0073] After that, if necessary, the shape of the metal support substrate (10) is processed by etching the metal support substrate (10).

[0074] In this way, a wiring circuit board (X2) can be manufactured.

[0075] In the wiring circuit board (X2), the terminal portion (E') has a via portion (32) connected to the metal support substrate (10), and a tail portion (T) extends from the terminal portion (E), and the tail portion (T) has a via portion (34) connected to the metal support substrate (10). That is, in the wiring circuit board (X2), the terminal portion (E') having a VOP structure is electrically connected to the metal support substrate (10) through the via portion (32) within the VOP structure, and is also electrically connected to the metal support substrate (10) through the via portion (34) outside the VOP structure. Such a configuration is suitable for reducing the resistance of the electrical connection between the terminal portion (E') and the metal support substrate (10) while suppressing the enlargement of each of the via portion (32) and the via portion (34). Accordingly, the wiring circuit board (X2), like the wiring circuit board (X1), is suitable for high-density wiring, and at the same time, in the terminal section, is suitable for realizing good connectivity to external component terminals and low-resistance ground connection.

[0076] Additionally, in the wiring circuit board (X2), the configuration in which the terminal portion (E) has a via portion (32) and the tail portion (T) has a via portion (34) is preferred from the perspective of noise suppression of the signal wiring when the signal wiring is arranged along the terminal portion (E) and the tail portion (T) (the noise suppression effect is higher than in the case where there is no via portion (32) or no via portion (34)).

[0077] In the wiring circuit board (X2), as described above with reference to FIGS. 4 and FIG. 5 with respect to the wiring circuit board (X1), the tail line portion (T) may have a plurality of via portions (34). The plurality of via portions (34) are arranged in a row, for example.

[0078] In the wiring circuit board (X2), the tail line portion (T) may have a shape other than a shape that extends straight from the terminal portion (E') when viewed from a plane. For example, the tail line portion (T) may have a first portion (Ta) that extends from the terminal portion (E') and a second portion (Tb) that extends in a direction intersecting the extension direction of the first portion (Ta), just as described above with reference to FIG. 6 with respect to the wiring circuit board (X1).

[0079] In the wiring circuit board (X2), as described above with reference to FIGS. 7 and FIG. 8 with respect to the wiring circuit board (X1), two terminal sections (E') (terminal section (E1') and terminal section (E2')) connected by a tail section (T) may be provided.

[0080] In the wiring circuit board (X2), the terminal portion (E') may have a plurality of via portions (32) as described above with reference to (A) and (B) of FIG. 9 with respect to the wiring circuit board (X1).

[0081] The technical advantages in these variations are as described above with respect to the wiring circuit board (X1).

[0082] The embodiments described above are examples of the present invention and should not be interpreted as limiting the present invention. Variations of the present invention that are evident to those skilled in the art are included in the following claims.

[0083] The wiring circuit board of the present invention can be applied to a wiring circuit board having a metal support substrate as a support substrate. Explanation of the symbols

[0084] X1, X2: Wiring circuit boards D: Thickness direction 10: Metal support substrate 20, 40: Insulating layer 30, 30A: Conductor layer E, E': Terminal section T: Tail section 31, 31': Pad section 32: Biabu (1st Biabu) 33: Base 34: Biabu (Second Biabu)

Claims

Claim 1 A wiring circuit board comprising a metal support substrate, an insulating layer, and a conductor layer in this order in the thickness direction, wherein the conductor layer includes a terminal portion and a tail portion extending from the terminal portion, wherein the terminal portion has a first via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the tail portion has a width different from the width of the terminal portion in a direction orthogonal to the extension direction of the tail portion, and has a base portion connected to the terminal portion and a second via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the connection area of ​​the second via portion to the metal support substrate is larger than the connection area of ​​the first via portion to the metal support substrate, and the ratio of the connection area of ​​the second via portion to the connection area of ​​the first via portion to the metal support substrate is 1.2 or more. Claim 2 In claim 1, a wiring circuit board having a tail portion having a plurality of second via portions. Claim 3 A wiring circuit board according to claim 2, wherein the sum of the connection areas of the plurality of second via portions for the metal support substrate is larger than the connection area of ​​the first via portion for the metal support substrate. Claim 4 A wiring circuit board according to claim 1, wherein the terminal portion comprises a first conductor layer on the insulating layer side and a second conductor layer on the first conductor layer. Claim 5 A wiring circuit board according to claim 1, wherein the conductor layer comprises two terminal portions, and the tail portion extends from one terminal portion to the other terminal portion. Claim 6 A wiring circuit board comprising a metal support substrate, an insulating layer, and a conductor layer in this order in the thickness direction, wherein the conductor layer includes a terminal portion and a tail portion extending from the terminal portion, wherein the terminal portion has a first via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the tail portion has a width different from the width of the terminal portion in a direction orthogonal to the extension direction of the tail portion, and has a base portion connected to the terminal portion and a second via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the terminal portion includes a first conductor layer on the insulating layer side and a second conductor layer on the first conductor layer. Claim 7 A wiring circuit board comprising a metal support substrate, an insulating layer, and a conductor layer in this order in the thickness direction, wherein the conductor layer includes a terminal portion and a tail portion extending from the terminal portion, wherein the terminal portion has a first via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the tail portion has a width different from the width of the terminal portion in a direction orthogonal to the extension direction of the tail portion, and has a base portion connected to the terminal portion and a second via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the conductor layer includes two terminal portions and the tail portion extends from one terminal portion to the other terminal portion. Claim 8 A wiring circuit board comprising a metal support substrate, an insulating layer, and a conductor layer in this order in the thickness direction, wherein the conductor layer includes a terminal portion and a tail portion extending from the terminal portion, wherein the terminal portion has a first via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the tail portion has a width different from the width of the terminal portion in a direction orthogonal to the extension direction of the tail portion, and has a base portion connected to the terminal portion and a second via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein one tail portion has a plurality of the second via portions. Claim 9 A wiring circuit board comprising a metal support substrate, an insulating layer, and a conductor layer in this order in the thickness direction, wherein the conductor layer includes a terminal portion and a tail portion extending from the terminal portion, wherein the terminal portion has a first via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the tail portion has a width different from the width of the terminal portion in a direction orthogonal to the extension direction of the tail portion, and has a base portion connected to the terminal portion and a second via portion penetrating the insulating layer in the thickness direction and connected to the metal support substrate, wherein the terminal portion has a plurality of the first via portions.

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