Wiring circuit board

Abstract

A wiring circuit substrate (1) has a metal support layer (2), a base insulating layer (3) disposed on one side in the thickness direction of the metal support layer (2), and a conductor layer (4) disposed on one side in the thickness direction of the base insulating layer (3) and having a first terminal (15) and a ground wire residual portion (18) electrically connected to the first terminal (15). The base insulating layer (3) has a through-hole (30A) that penetrates in the thickness direction. The ground wire residual portion (18) has an opening (18C) that is continuous in a manner surrounding the through-hole (30A).

Description

Technical Field

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

[0002] A wiring circuit board is known in the past, which has a metal support substrate, a base insulating layer disposed on the metal support substrate, and a conductor layer disposed on the base insulating layer. The conductor layer includes a wiring circuit pattern that electrically connects two terminals and a grounding pattern that electrically connects the terminals and the metal support substrate.

[0003] In such wiring circuit boards, chemical plating is sometimes formed on the surface of the conductor layer. However, the deposition rate of chemical plating in wiring patterns and in grounding patterns differs depending on whether these patterns are electrically connected to the metal support substrate, making it difficult to form a uniform chemical plating in the conductor layer.

[0004] Therefore, the following research was conducted: In the manufacturing of wiring circuit boards, while the wiring circuit pattern is electrically connected to the metal support substrate, the conductor layer is chemically plated, and then the electrical connection between the wiring circuit pattern and the metal support substrate is severed.

[0005] For example, a method for manufacturing a suspended substrate with circuitry has been proposed as follows: after forming a base insulating layer having a second opening on a metal support substrate, a metal thin film is formed on the base insulating layer and the portion of the metal support substrate exposed in the second opening; then, a wiring circuit pattern is formed on the metal thin film; the wiring circuit pattern is chemically plated; then, a first opening surrounding the second opening is formed on the metal support substrate; and the electrical connection between the wiring circuit pattern and the metal support substrate is severed (see, for example, Patent Document 1).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2005-100488 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] However, in the manufacturing method of the suspended substrate with circuitry described in Patent Document 1, a first opening is formed in the metal support substrate, thereby cutting off the electrical connection between the wiring circuit pattern and the metal support substrate. Therefore, there is a defect such as a reduction in the strength of the suspended substrate with circuitry.

[0011] The present invention provides a wiring circuit board capable of forming a uniform chemical plating layer on a conductor layer and suppressing the reduction in strength, as well as a method for manufacturing a wiring circuit board with high manufacturing efficiency.

[0012] Solution for solving the problem

[0013] The present invention [1] includes a wiring circuit board having: a metal support layer; an insulating layer disposed on one side of the metal support layer in the thickness direction; and a conductor layer disposed on one side of the insulating layer in the thickness direction, having a terminal portion and a ground wire residual portion electrically connected to the terminal portion, the insulating layer having a through hole extending through in the thickness direction, and the ground wire residual portion having an opening continuously surrounding the through hole.

[0014] However, the residual grounding conductor is formed during the manufacturing of the wiring circuit board by removing a portion of the grounding conductor that electrically connects the terminal portion and the metal support layer. Therefore, before the grounding conductor is removed, the terminal portion and the metal support layer are electrically connected, thus enabling the uniform formation of a chemical plating layer on the conductor layer.

[0015] Furthermore, according to the above structure, the remaining portion of the grounding conductor has a continuous opening in the form of a through-hole surrounding the insulating layer. Therefore, the remaining portion of the grounding conductor and the metal support layer can be insulated without forming an opening in the metal support layer, thus suppressing the reduction in strength of the wiring circuit board.

[0016] The present invention [2] includes the wiring circuit board described in [1] above, wherein the opening is connected to the through hole.

[0017] With this structure, the opening of the grounding wire remnant is connected to the through hole of the insulation layer, thus reliably insulating the grounding wire remnant from the metal support layer.

[0018] The present invention [3] includes the wiring circuit board described in [1] above, wherein the grounding conductor residual portion has: a conductive portion disposed in the opening and filling the through hole; and a peripheral portion that divides the opening and is located at a position spaced apart from the conductive portion.

[0019] With this structure, since the periphery of the grounding conductor remnant is located at a distance from the conductive portion filled in the through hole, the grounding conductor remnant and the metal support layer can be reliably insulated.

[0020] The present invention [4] includes a method for manufacturing a wiring circuit board, the method comprising: a step of preparing a metal support layer; a step of forming an insulating layer on one side of the metal support layer in the thickness direction, the insulating layer having a through hole extending through in the thickness direction; a step of forming a conductor layer having a terminal portion disposed on one side of the insulating layer in the thickness direction and a grounding wire electrically connecting the terminal portion and the metal support layer; a step of chemically plating the conductor layer; and a step of removing a portion of the grounding wire to form a residual portion of the grounding wire to insulate the terminal portion and the metal support layer, the residual portion of the grounding wire having an opening continuously surrounding the through hole.

[0021] According to this method, after forming an insulating layer with through holes, a conductor layer with terminals and a grounding wire electrically connecting the terminals and the metal support layer is formed. Then, after chemical plating the conductor layer, a portion of the grounding wire is removed to form a residual portion of the grounding wire, so as to insulate the terminals and the metal support layer.

[0022] That is, when performing chemical plating on the conductor layer, the grounding wire electrically connects the terminal part and the metal support layer, thus enabling the formation of a uniform chemical plating layer on the conductor layer.

[0023] Furthermore, since the residual portion of the grounding conductor formed by removing a portion of the grounding conductor has a continuous opening that surrounds the through-hole, the residual portion of the grounding conductor can be insulated from the metal support layer without forming an opening in the metal support layer. Therefore, it is possible to suppress the reduction in strength of the wiring circuit board.

[0024] The present invention [5] includes a method for manufacturing a wiring circuit board as described in [4] above, wherein, in the process of removing a portion of the grounding wire, the opening is connected to the through hole.

[0025] According to this method, since the opening of the grounding wire remnant is connected to the through hole, the grounding wire remnant and the metal support layer can be reliably insulated.

[0026] The present invention [6] includes a method for manufacturing a wiring circuit board as described in [4] above, wherein, in a process of removing a portion of the grounding wire, a conductive portion and a peripheral portion are formed, the conductive portion being disposed within the opening and filling the through hole, and the peripheral portion dividing the opening and being located at a position spaced apart from the conductive portion.

[0027] According to this method, since the periphery of the grounding conductor remnant is formed at intervals relative to the conductive portion filling the through hole, the grounding conductor remnant and the metal support layer can be reliably insulated.

[0028] The present invention [7] includes a method for manufacturing a wiring circuit board according to any one of [4] to [6] above, wherein the method for manufacturing the wiring circuit board further includes: a step of forming a seed film on one side of the insulating layer in the thickness direction and on one side of the metal support layer exposed from the insulating layer in the thickness direction after the step of forming the insulating layer and before the step of forming the conductor layer; a step of removing the seed film exposed from the conductor layer after the step of forming the conductor layer and before the step of performing the chemical plating; and a step of removing the seed film exposed by the removal of the grounding wire after the step of removing a portion of the grounding wire.

[0029] According to this method, after forming a seed film on the insulating layer and on the metal support layer exposed from the insulating layer, a conductor layer is formed on the seed film. Then, after chemical plating the conductor layer, a portion of the grounding conductor is removed to form a residual portion of the grounding conductor. Finally, the seed film exposed by the removal of the grounding conductor is removed.

[0030] However, if any seed film remains exposed after the removal of the grounding wire, the remaining portion of the grounding wire and the metal support layer may be electrically connected by the seed film. On the other hand, by removing the seed film exposed after the removal of the grounding wire according to the method described above, it is possible to further reliably insulate the remaining portion of the grounding wire and the metal support layer.

[0031] The effects of the invention

[0032] According to the wiring circuit substrate of the present invention, a uniform chemical plating layer can be formed on the conductor layer, and the reduction in strength can be suppressed.

[0033] Furthermore, the wiring circuit board manufacturing method according to the present invention can efficiently manufacture the above-mentioned wiring circuit board. Attached Figure Description

[0034] [ Figure 1 ] Figure 1 This is a top view showing a first embodiment of the wiring circuit board of the present invention.

[0035] [ Figure 2 ] Figure 2 express Figure 1 The diagram shows a cross-sectional view of the wiring circuit board along line A-A.

[0036] [ Figure 3 ] Figure 3 A~ Figure 3 E is Figure 2 The diagram shows the manufacturing process of the wiring circuit board. Figure 3 A represents the process of preparing the metal support layer. Figure 3 B indicates the process of forming the base insulating layer. Figure 3 C represents the process of forming the seed film. Figure 3 D represents the process of forming the conductor layer. Figure 3 E indicates the process of forming the first coating layer.

[0037] [ Figure 4 ] Figure 4 F~ Figure 4 J is next Figure 3 Manufacturing process diagram of the wiring circuit board of E. Figure 4 F indicates the process of forming the covering insulation layer. Figure 4 G indicates the process of removing the first plating layer exposed from the covering insulation layer. Figure 4 H indicates the process of forming the residual part of the grounding conductor. Figure 4 I indicates the process of removing the seed film exposed by the formation of residual portions through the grounding wire. Figure 4 J indicates the process of forming the second coating layer.

[0038] [ Figure 5 ] Figure 5 yes Figure 3 D shows a top view of a conductor layer with a grounding wire.

[0039] [ Figure 6 ] Figure 6 This is a top view showing a second embodiment of the wiring circuit board of the present invention.

[0040] [ Figure 7 ] Figure 7 express Figure 6 The diagram shows a B-B cross-sectional view of the wiring circuit board.

[0041] [ Figure 8 ] Figure 8 This is a top view showing a third embodiment of the wiring circuit board of the present invention. Detailed Implementation

[0042] <First Embodiment>

[0043] 1. Wiring circuit board

[0044] Reference Figure 1 and Figure 2 The wiring circuit board 1, which is the first embodiment of the wiring circuit board of the present invention, will be described.

[0045] like Figure 1 and Figure 2 As shown, the wiring circuit board 1 is in the shape of a sheet with thickness. The wiring circuit board 1 has a rectangular shape, for example, when viewed from above. Examples of wiring circuit boards 1 include flexible printed wiring boards with a metal support layer 2 as a reinforcing layer and suspended boards with circuits having a metal support layer 2 as a suspension (spring) layer.

[0046] Specifically, such as Figure 2 As shown, the wiring circuit board 1 has a metal support layer 2, a base insulating layer 3 as an example of an insulating layer, a seed film 6, a conductor layer 4, a first plating layer 7, a cover insulating layer 5, and a second plating layer 8.

[0047] The metal support layer 2 has a flat plate shape. The metal support layer 2 has the same external shape as the wiring circuit board 1. The thickness of the metal support layer 2 is not particularly limited.

[0048] The material of the metal support layer 2 can be appropriately selected and used from known or conventional metallic materials (specifically, metallic materials). Specifically, examples of metallic materials include metals classified as Groups 1 to 16 in the periodic table, alloys containing two or more of these metals, etc. Furthermore, the metal element can also be any of transition metals or typical metals.

[0049] More specifically, as metallic elements, examples include Group 2 main metals such as calcium, Group 4 subgroup metals such as titanium and zirconium, Group 5 subgroup metals such as vanadium, Group 6 subgroup metals such as chromium, molybdenum, and tungsten, Group 7 subgroup metals such as manganese, Group 8 subgroup (column 8) metals such as iron, Group 8 subgroup (column 9) metals such as cobalt, Group 8 subgroup (column 10) metals such as nickel and platinum, Group 1 subgroup metals such as copper, silver, and gold, Group 2 subgroup metals such as zinc, Group 3 main metals such as aluminum and gallium, and Group 4 main metals such as germanium and tin.

[0050] Such metallic materials can be used alone or in combination with two or more. Among metallic materials, alloys containing two or more metallic elements are preferred, alloys that can be etched simultaneously with conductor layer 4 are more preferred, and stainless steel and copper-containing alloys are particularly preferred.

[0051] The substrate insulating layer 3 is disposed on one side of the metal support layer 2 in the thickness direction, specifically, on one side of the metal support layer 2 in the thickness direction. The substrate insulating layer 3 has a thickness and has a flat side in the thickness direction and another side.

[0052] like Figure 1 As shown, the substrate insulating layer 3 has a first terminal configuration portion 30, a second terminal configuration portion 31, and a wiring configuration portion 32. The first terminal configuration portion 30 and the second terminal configuration portion 31 are located at a distance from each other, sandwiching the wiring configuration portion 32. The first terminal configuration portion 30 and the wiring configuration portion 32 are continuous.

[0053] The first terminal configuration portion 30 has a plurality of through holes 30A. That is, the substrate insulating layer 3 has a plurality of through holes 30A. The plurality of through holes 30A are located at intervals from each other in a direction orthogonal to the thickness direction of the first terminal configuration portion 30. More specifically, the plurality of through holes 30A are located at intervals from each other in the width direction of the first terminal 15, which will be described later. The through holes 30A penetrate the first terminal configuration portion 30 in the thickness direction (see reference). Figure 2 The through hole 30A has a circular shape when viewed from above.

[0054] The second terminal configuration portion 31 is located on the opposite side of the first terminal configuration portion 30 relative to the wiring configuration portion 32. The second terminal configuration portion 31 is continuous with the wiring configuration portion 32. Neither the first terminal configuration portion 30 nor the second terminal configuration portion 31 is covered by the covering insulation layer 5 and is exposed from it. The wiring configuration portion 32 is located between the first terminal configuration portion 30 and the second terminal configuration portion 31. The wiring configuration portion 32 is covered by the covering insulation layer 5.

[0055] Examples of materials that can be used as the base insulating layer 3 include resins such as polyimide (insulating resin materials). The thickness of the base insulating layer 3 is not particularly limited, but may be, for example, 1 μm or more and 1000 μm or less.

[0056] like Figure 2 As shown, the seed film 6 is disposed on one side of the substrate insulating layer 3 in the thickness direction. The seed film 6 has a pattern corresponding to the conductor layer 4. Examples of materials for the seed film 6 include metals such as copper, chromium, and nickel, and their alloys. The seed film 6 can be formed from one layer or from two or more layers. The thickness of the seed film 6 is, for example, 0.01 μm or more, for example, 1 μm or less, preferably 0.1 μm or less.

[0057] The conductor layer 4 is disposed on one side of the substrate insulating layer 3 in the thickness direction, specifically, on one side of the seed film 6 in the thickness direction. For example... Figure 1 As shown, conductor layer 4 includes grounding pattern 10 and multiple wiring patterns 11.

[0058] The grounding pattern 10 has a grounding terminal 12 and a grounding wiring 13.

[0059] The grounding terminal 12 is disposed on one side of the first terminal placement portion 30 in the thickness direction. Specifically, the grounding terminal 12 is disposed on one side of the first terminal placement portion 30 in the thickness direction through the seed film 6. The grounding terminal 12 extends in a predetermined direction and has a rectangular shape (square pad shape) when viewed from above.

[0060] Grounding wiring 13 electrically connects grounding terminal 12 and metal support layer 2. Grounding wiring 13 is continuous from grounding terminal 12 and extends from first terminal configuration portion 30 to wiring configuration portion 32. Specifically, grounding wiring 13 is disposed across the thickness direction of first terminal configuration portion 30 and wiring configuration portion 32, separated by seed film 6. Grounding wiring 13 penetrates wiring configuration portion 32 in the thickness direction and is grounded in metal support layer 2. The width direction (orthogonal to the length direction) of grounding wiring 13 is smaller than the width direction (orthogonal to the length direction) of grounding terminal 12.

[0061] Each of the multiple wiring patterns 11 has a first terminal 15, a second terminal 16, a connecting wiring 17, and a grounding wire residue 18, which are examples of terminal portions. That is, the conductor layer 4 has multiple first terminals 15 and multiple grounding wire residue portions 18.

[0062] The first terminal 15 is disposed on one side of the first terminal placement portion 30 in the thickness direction. Specifically, the first terminal 15 is disposed on one side of the first terminal placement portion 30 in the thickness direction, with the seed film 6 in between (see reference). Figure 2 The first terminal 15 extends along a predetermined direction and has a rectangular shape (square pad shape) when viewed from above. The first terminal 15 is located between the through hole 30A and the covering insulating layer 5 in the length direction of the first terminal 15. The ground terminal 12 and a plurality of first terminals 15 are arranged at intervals from each other in the width direction (the direction orthogonal to the length direction) of the first terminal 15.

[0063] The second terminal 16 is disposed on one side of the second terminal placement portion 31 in the thickness direction. Specifically, the second terminal 16 is disposed on one side of the second terminal placement portion 31 in the thickness direction, with the seed film 6 in between. The second terminal 16 extends in a predetermined direction and has a rectangular shape (square pad shape) when viewed from above. A plurality of second terminals 16 are arranged at intervals from each other in the width direction (the direction orthogonal to the length direction) of the second terminal 16.

[0064] The connecting wire 17 electrically connects the first terminal 15 and the second terminal 16. The connecting wire 17 extends continuously from the first terminal 15 on the first terminal configuration portion 30, passes through the wiring configuration portion 32, and connects to the second terminal 16 on the second terminal configuration portion 31. Specifically, the connecting wire 17 is disposed across the thickness direction of the first terminal configuration portion 30, the thickness direction of the wiring configuration portion 32, and the thickness direction of the second terminal configuration portion 31, separated by the seed film 6. The width direction (orthogonal to the length direction) of the connecting wire 17 is smaller than the width direction (orthogonal to the length direction) of the first terminal 15.

[0065] The grounding conductor residue 18 is the remaining portion of the grounding conductor 19 after partial removal during the manufacturing method of the wiring circuit board 1 described later (see reference). Figure 5 The residual portion 18 of the grounding conductor is disposed on one side of the first terminal placement portion 30 in the thickness direction (see reference). Figure 2 In detail, the grounding wire remnant 18 is disposed on one side of the first terminal arrangement portion 30 in the thickness direction, through the seed film 6. The grounding wire remnant 18 is electrically connected to the first terminal 15.

[0066] The grounding conductor remnant 18 has a first remnant 18A and a second remnant 18B. The first remnant 18A connects the first terminal 15 and the second remnant 18B. The first remnant 18A extends continuously from the first terminal 15 to the side opposite to the connecting wiring 17. The second remnant 18B is located on the side opposite to the first terminal 15 relative to the first remnant 18A. The second remnant 18B has an opening 18C, which has a ring shape when viewed from above. That is, the grounding conductor remnant 18 has an opening 18C.

[0067] When viewed from the thickness direction, opening 18C is continuous in a manner that surrounds through-hole 30A. Opening 18C and through-hole 30A are connected in the thickness direction (see reference). Figure 2 The opening 18C has a circular shape when viewed from above. The inner diameter of the opening 18C is larger than the inner diameter of the through hole 30A. The center of the opening 18C and the center of the through hole 30A coincide with each other. That is, the opening 18C and the through hole 30A are concentric circles when viewed from the thickness direction.

[0068] The thickness of such conductor layer 4 is, for example, 1 μm or more, for example, 200 μm or less, preferably 100 μm or less.

[0069] Furthermore, in this embodiment, the conductor layer 4 is composed of a single layer, but it can also be composed of multiple layers. For example, the first terminal 15 can be composed of multiple layers, and the grounding wire residue 18 can be composed of a single layer.

[0070] Materials that can be used as conductor layer 4 include, for example, metallic elements such as copper, silver, gold, iron, aluminum, and chromium, as well as alloys containing two or more of these metallic elements. Copper and copper alloys are preferred examples of metals containing copper.

[0071] like Figure 2As shown, the first plating layer 7 improves the adhesion between the conductor layer 4 and the covering insulating layer 5. The first plating layer 7 is a chemical plating layer located between the conductor layer 4 and the covering insulating layer 5. Specifically, the first plating layer 7 is configured to cover the surfaces of the grounding wiring 13 and the connecting wiring 17 located on the wiring configuration portion 32. Examples of materials for the first plating layer 7 include metallic elements such as nickel, tin, silver, and palladium, as well as alloys containing two or more of these metallic elements; nickel is preferred. The first plating layer 7 can be formed in one layer or in two or more layers. The thickness of the first plating layer 7 is, for example, 0.01 μm or more, preferably 0.02 μm or more, for example, 1 μm or less, and preferably 0.5 μm or less.

[0072] The insulating layer 5 is disposed on one side of the wiring arrangement portion 32 in the thickness direction, covering the grounding wiring 13 and the connecting wiring 17. Additionally, the insulating layer 5 exposes the grounding terminal 12, a plurality of first terminals 15, a plurality of grounding wire remnants 18, and a plurality of second terminals 16 (see reference). Figure 1 The material used for the covering insulating layer 5 may be, for example, the same material as the base insulating layer 3. The thickness of the covering insulating layer 5 is not particularly limited, but may be, for example, 1 μm or more and 1000 μm or less.

[0073] The second plating layer 8 is a chemical plating layer, which covers the surface of the conductor layer 4 exposed from the covering insulating layer 5 (specifically, the grounding terminal 12, the plurality of first terminals 15, the plurality of grounding wire remnants 18, and the plurality of second terminals 16) and the surface of the metal support layer 2. The material of the second plating layer 8 can be, for example, metallic elements such as nickel and gold, and alloys containing these metallic elements. The second plating layer 8 can be formed by one layer or by two or more layers. For example, the second plating layer 8 can also be formed by laminating a first layer containing nickel and a second layer containing gold. The thickness of the second plating layer 8 is, for example, 0.1 μm or more, preferably 0.25 μm or more, for example, 5 μm or less, preferably 2.5 μm or less.

[0074] 2. Manufacturing method of wiring circuit board

[0075] Next, refer to Figure 3 A~ Figure 5 The manufacturing method of wiring circuit board 1 will be explained.

[0076] The manufacturing method of the wiring circuit board 1 includes a process of preparing the metal support layer 2 (see reference). Figure 3 A) The process of forming the substrate insulating layer 3 (refer to...) Figure 3 B) The process of forming seed membrane 6 (refer to...) Figure 3 C) The process of forming conductor layer 4A (refer to...) Figure 3 D) The process of removing the seed film 6 exposed from the conductor layer 4A (refer to...) Figure 3E), the process of forming the first coating layer 7 (refer to...) Figure 3 E) The process of forming the covering insulation layer 5 (refer to...) Figure 4 F), the process of removing the first plating layer 7 exposed from the covering insulation layer 5 (refer to...) Figure 4 G), the process of forming the residual part 18 of the grounding conductor (refer to...) Figure 4 H), the process of removing the seed film 6 exposed by the formation of the residual portion 18 through the grounding wire (refer to) Figure 4 I) and the process of forming the second coating layer 8 (refer to) Figure 4 J).

[0077] like Figure 3 As shown in Figure A, firstly, prepare the metal support layer 2.

[0078] Next, as Figure 3 As shown in Figure B, a substrate insulating layer 3 with through holes 30A is formed on one side of the metal support layer 2 in the thickness direction. Specifically, a varnish containing the aforementioned resin is applied to one side of the metal support layer 2 in the thickness direction and allowed to dry to form a substrate film. Then, the substrate film is exposed and developed using a photomask (not shown), and cured by heating as needed, so that the substrate insulating layer 3 is formed as described above.

[0079] Next, as Figure 3 As shown in Figure C, a seed film 6 is formed on one side of the substrate insulating layer 3 in the thickness direction and on the other side of the metal support layer 2 in the thickness direction of the portion exposed from the substrate insulating layer 3. Methods for forming the seed film 6 include, for example, sputtering, electroplating, or electroless plating, with sputtering being a preferred method.

[0080] Next, as Figure 3 As shown in Figure D, a conductor layer 4A is formed on one side of the seed film 6 in the thickness direction. Figure 5 As shown, conductor layer 4A has a plurality of grounding wires 19 replacing the plurality of grounding wire remnants 18, and otherwise has the same structure as conductor layer 4. Furthermore, conductor layer 4A with grounding wires 19 will be referred to below as preconductor layer 4A to distinguish it from conductor layer 4 with grounding wire remnants 18.

[0081] The grounding conductor 19 electrically connects the first terminal 15 and the portion of the metal support layer 2 exposed through the through hole 30A. The grounding conductor 19 has a first portion 19A and a second portion 19B.

[0082] Part 19A is located on one side of the first terminal configuration portion 30 in the thickness direction. Specifically, it is disposed on one side of the first terminal configuration portion 30 in the thickness direction, separated by the seed film 6 (see reference). Figure 3D). Part 19A is continuous with Terminal 15. Part 2 19B electrically connects Part 19A and Metal Support Layer 2 via Through Hole 30A. Part 2 19B is continuous with Part 19A and is located on one side of the thickness direction of Metal Support Layer 2 within Through Hole 30A. Specifically, Part 2 19B fills the Through Hole 30A and contacts the thickness direction side of Metal Support Layer 2 through Seed Film 6 (see...). Figure 3 E).

[0083] To form such a preconductor layer 4A, a resist having a pattern complementary to the preconductor layer 4A is disposed on the seed film 6, for example by electroplating (preferably copper plating), which is not illustrated. Then, the resist is removed.

[0084] Based on the above, a preconductor layer 4A having a first terminal 15 and a grounding wire 19 is formed.

[0085] Next, as Figure 3 As shown in E, the seed film 6 exposed from the preconductor layer 4A is removed by a known etching method (e.g., wet etching). Examples of etching solutions for the seed film 6 include aqueous sodium hydroxide solution, potassium permanganate solution, and sodium metasilicate solution.

[0086] Next, the preconductor layer 4A is chemically plated using a first chemical plating solution containing metal ions (e.g., nickel ions) of the material of the first plating layer 7 described above.

[0087] Thus, the first plating layer 7 is formed in such a way as to cover the exposed preconductor layer 4A (grounding terminal 12, grounding wiring 13, first terminal 15, second terminal 16, connecting wiring 17, and grounding wire 19).

[0088] Next, as Figure 4 As shown in Figure F, the covering insulating layer 5 is formed on one side of the base insulating layer 3 in the thickness direction, specifically on one side of the wiring configuration portion 32 in the thickness direction, so as to cover the grounding wiring 13 and the connecting wiring 17. Furthermore, the covering insulating layer 5 is formed in the pattern described above.

[0089] Specifically, a varnish containing the aforementioned resin is applied to one side of the substrate insulating layer 3 in the thickness direction and allowed to dry to form a cover film. Then, the cover film is exposed and developed using a photomask (not shown), and cured by heating as needed, so that the cover insulating layer 5 is formed into the pattern described above.

[0090] Next, as Figure 4 As shown in G, the first plating layer 7 exposed from the covering insulating layer 5 is removed by a known etching method (e.g., wet etching). Examples of etching solutions for the first plating layer 7 include, for example, hydrogen peroxide sulfate and hydrogen peroxide nitric acid.

[0091] Next, as Figure 4 As shown in Figure H, the central portion of the second part 19B is removed by etching to insulate the first terminal 15 from the metal support layer 2. Specifically, the central portion of the second part 19B is removed by wet etching to form the opening 18C described above. Examples of such etching solutions include ferric chloride solution.

[0092] This forms a residual portion 18 of the grounding conductor with an opening 18C. The opening 18C is continuously formed in a manner that surrounds the through hole 30A and communicates with the through hole 30A. In addition, the opening 18C exposes the seed membrane 6 located within the opening 18C.

[0093] Furthermore, at this time, the metal support layer 2 can be partially etched simultaneously with the etching of the grounding wire 19. Alternatively, the etching of the metal support layer 2 can be performed independently of the etching of the grounding wire 19.

[0094] Next, as Figure 4 As shown in Figure 1, the seed film 6 exposed by the removal via the grounding wire 19 is removed. Specifically, the seed film 6 located within the opening 18C is removed by a known etching method (e.g., wet etching). As a result, the opening 18C partially exposes the metal support layer 2 via the through-hole 30A.

[0095] Next, as Figure 4 As shown in Figure J, a second chemical plating solution containing metal ions of the material described above as the second plating layer 8 is used to perform chemical plating on the portions of the conductor layer 4 exposed from the covering insulating layer 5 (specifically, the grounding terminal 12, the first terminal 15, the remaining portion 18 of the grounding wire, and the second terminal 16) and the metal support layer 2. Furthermore, if the second plating layer 8 is formed of multiple layers, the chemical plating is repeated. For example, after chemical plating using a second chemical plating solution containing first metal ions (e.g., nickel ions), chemical plating is performed using a second chemical plating solution containing second metal ions (e.g., gold ions).

[0096] Thus, the second plating layer 8 is formed in such a way that it covers the exposed conductor layer 4 (specifically the grounding terminal 12, the first terminal 15, the grounding wire remnant 18, and the second terminal 16) and the metal support layer 2.

[0097] Based on the above, a wiring circuit board 1 is manufactured.

[0098] The application of such a wiring circuit board 1 is not particularly limited and can be used in various fields. The wiring circuit board 1 is used in various applications such as wiring circuit boards for electronic equipment (wiring circuit boards for electronic components) and wiring circuit boards for electrical equipment (wiring circuit boards for electrical components). Examples of wiring circuit boards for electronic devices and electrical devices include, for example, sensor wiring circuit boards used in sensors such as position information sensors, obstacle detection sensors, and temperature sensors; conveyor wiring circuit boards used in conveyor vehicles such as automobiles, trams, airplanes, and work vehicles; video device wiring circuit boards used in video devices such as flat panel displays, flexible displays, and projection video devices; communication relay equipment wiring circuit boards used in communication relay equipment such as network equipment and large communication equipment; information processing terminal wiring circuit boards used in information processing terminals such as computers, tablets, smartphones, and home game consoles; movable equipment wiring circuit boards used in movable devices such as drones and robots; medical device wiring circuit boards used in medical devices such as wearable medical devices and medical diagnostic devices; electrical device wiring circuit boards used in electrical devices such as refrigerators, washing machines, vacuum cleaners, and air conditioning equipment; and video recording electronic devices wiring circuit boards used in video recording electronic devices such as digital cameras and DVD recording devices.

[0099] like Figure 1 As shown, the residual portion 18 of the grounding wire is formed during the manufacturing of the wiring circuit board 1 by removing a portion of the grounding wire 19 that electrically connects the first terminal 15 and the metal support layer 2 (see reference). Figure 4 G). Therefore, before the grounding wire 19 is removed, the first terminal 15 and the metal support layer 2 are electrically connected, so that the first plating layer 7 can be uniformly formed in the conductor layer 4.

[0100] Furthermore, the grounding wire residue 18 has a continuous opening 18C that surrounds the through hole 30A of the substrate insulation layer 3. Therefore, the grounding wire residue 18 and the metal support layer 2 can be insulated without forming an opening in the metal support layer 2, thus suppressing the reduction in strength of the wiring circuit board 1.

[0101] As a result, the grounding wire residue 18 can be configured without considering the reduction in strength of the wiring circuit board 1, thus increasing the degree of freedom in the configuration of the grounding wire residue 18.

[0102] In addition, such as Figure 2 As shown, the opening 18C of the grounding conductor remnant 18 is connected to the through hole 30A of the substrate insulation layer 3. Therefore, the grounding conductor remnant 18 and the metal support layer 2 can be reliably insulated.

[0103] In addition, such as Figure 3 B~ Figure 4 As shown in H, after forming the substrate insulating layer 3 with through holes 30A (refer to...) Figure 3 B), forming a preconductor layer 4A having a first terminal 15 and a grounding wire 19 electrically connecting the first terminal 15 and the metal support layer 2 (refer to...). Figure 3 D), then, after chemical plating the preconductor layer 4A (refer to...). Figure 3 E), remove the central portion of part 2 19B to form the grounding conductor residue 18, so as to insulate the first terminal 15 and the metal support layer 2 (see reference). Figure 4 H).

[0104] That is, when the conductor layer 4 is electroless plated, the grounding wire 19 electrically connects the first terminal 15 and the metal support layer 2, so that a uniform electroless plating layer can be formed in the preconductor layer 4A.

[0105] Furthermore, the grounding wire residue 18 formed by removing the central portion of the second part 19B has a continuous opening 18C surrounding the through hole 30A. Therefore, the grounding wire residue 18 and the metal support layer 2 can be insulated without forming an opening in the metal support layer 2. Thus, the reduction in strength of the wiring circuit board 1 can be suppressed.

[0106] Additionally, removing such Figure 4 H shows the seed film 6 exposed by the removal of the grounding wire 19. Therefore, the remaining portion of the grounding wire 18 and the metal support layer 2 can be insulated more reliably.

[0107] <Second Implementation>

[0108] Next, refer to Figure 6 This section describes a second embodiment of the wiring circuit board of the present invention. Furthermore, in the second embodiment, components identical to those in the first embodiment described above are labeled with the same reference numerals, and their descriptions are omitted.

[0109] In the first embodiment described above, such as Figure 2 As shown, opening 18C is connected to through hole 30A, but the structure of the remaining part of the grounding wire is not limited to this.

[0110] In the second embodiment, such as Figure 6 and Figure 7 As shown, the grounding conductor residual portion 18, in addition to having the first residual portion 18A and the second residual portion 18B, also has a third residual portion 18D as an example of a conductive portion.

[0111] The third residual portion 18D is disposed within the opening 18C and fills the through hole 30A. Furthermore, the third residual portion 18D contacts one side of the metal support layer 2 in the thickness direction, separated by the seed film 6. The third residual portion 18D has a circular shape when viewed from the thickness direction.

[0112] In this case, the second residual portion 18B is an example of a peripheral portion. The second residual portion 18B divides an opening 18C, which is located at a distance from the third residual portion 18D in a manner that surrounds the third residual portion 18D. The center of the opening 18C and the center of the third residual portion 18D coincide with each other. That is, the opening 18C and the third residual portion 18D are concentric circles when viewed from the thickness direction.

[0113] To manufacture the wiring circuit board 1 of the second embodiment, a preconductor layer 4A (see reference 1) is formed in the same manner as in the first embodiment. Figure 3 D), after chemically plating the preconductor layer 4A to form the first plating layer 7 (refer to...) Figure 3 E), forming a covering insulating layer 5 (refer to...) Figure 4 F), then, remove the first plating layer 7 exposed from the covering insulation layer 5 (refer to F). Figure 4 G), then, as Figure 6 The radial midpoint of the second portion 19B of the grounding conductor 19 is removed along the entire circumference, forming a second residual portion 18B and a third residual portion 18D. This forms the grounding conductor residual portion 18, and then, as shown... Figure 7 As shown, the seed film 6 exposed by the removal through the grounding wire 19 is removed, and then a second plating layer 8 is formed on the exposed conductor layer 4.

[0114] Based on the above description, the wiring circuit board 1 of the second embodiment is manufactured.

[0115] This second embodiment can achieve the same effect as the first embodiment described above. However, in the second embodiment, a portion of the seed film 6 may remain between the second residual portion 18B and the third residual portion 18D. Therefore, from the viewpoint of ensuring insulation between the first terminal 15 and the metal support layer 2, the first embodiment is preferred over the second embodiment.

[0116] <Third Implementation>

[0117] Next, refer to Figure 8 This section describes a third embodiment of the wiring circuit board of the present invention. Furthermore, in this third embodiment, components identical to those in the first embodiment are labeled with the same reference numerals, and their descriptions are omitted.

[0118] In the first embodiment described above, such as Figure 1As shown, the residual portion 18 of the grounding wire is disposed on the side opposite to the connecting wiring 17 relative to the first terminal 15, but the disposal of the residual portion of the grounding wire is not limited to this. In particular, the residual portion of the grounding wire can be disposed freely without considering the reduction in strength of the wiring circuit board 1, and therefore, it can also be disposed on the inner portion of the wiring circuit board 1.

[0119] In the third embodiment, such as Figure 8 As shown, the residual portion 18 of the grounding wire is integrally formed with the connecting wiring 17. In this case, the residual portion 18 of the grounding wire is located midway between the first terminal 15 and the second terminal 16 of the connecting wiring 17.

[0120] According to this third embodiment, the same effect as the first embodiment described above can be achieved.

[0121] <Variation Example>

[0122] In the first to third embodiments described above, as Figure 3 As shown in E, after removing the seed film 6 exposed from the preconductor layer 4A, as Figure 4 As shown in Figure I, the seed film 6 exposed by the removal of the grounding wire is removed. Alternatively, the seed film may not be removed after the formation of the preconductor layer, but may be removed together with the seed film exposed from the conductor layer after the removal of the grounding wire.

[0123] Furthermore, in the first to third embodiments described above, as follows: Figure 4 F and Figure 4 As shown in G, after removing the first plating 7 exposed from the covering insulation layer 5, a portion of the grounding conductor 19 is removed, but the order of removing the first plating and the grounding conductor is not limited to this. Alternatively, the first plating exposed from the covering insulation layer can be removed after the portion of the grounding conductor is removed.

[0124] Furthermore, in the first to third embodiments described above, as follows: Figure 4 As shown in J, the second plating layer 8 is formed by chemical plating, but the method for forming the second plating layer is not limited to this. For example, after removing the first plating layer and before removing a portion of the grounding wire, the grounding wire can also be used as the electroplating wire to form the second plating layer by electroplating (see reference). Figure 4 G).

[0125] Furthermore, in the first to third embodiments described above, after forming the seed film, the conductor layer is formed by an additive method of forming a conductor layer on the seed film; however, the method of forming the conductor layer is not limited to this. The conductor layer can also be formed by a subtractive method.

[0126] Such modifications can achieve the same effect as the first embodiment described above. Furthermore, the first to third embodiments and their modifications can be appropriately combined.

[0127] Furthermore, the above-described invention is provided as an illustrative embodiment of the present invention, but it is merely illustrative and should not be interpreted as limiting. Modifications of the invention that will be apparent to those skilled in the art are included in the foregoing claims.

[0128] Industrial availability

[0129] The wiring circuit board of the present invention is applicable to various uses, such as wiring circuit boards for electronic devices (wiring circuit boards for electronic components) and wiring circuit boards for electrical equipment (wiring circuit boards for electrical components).

[0130] Explanation of reference numerals in the attached figures

[0131] 1. Wiring circuit board; 2. Metal support layer; 3. Substrate insulating layer; 4. Conductor layer; 4A. Preconductor layer; 6. Seed film; 15. Terminal 1; 18. Grounding wire remnant; 18A. First remnant; 18B. Second remnant; 18C. Opening; 18D. Third remnant; 19. Grounding wire; 30A. Through hole.

Claims

1. A wiring circuit board, characterized in that, The wiring circuit board has the following features: Metal support layer; An insulating layer disposed on one side of the metal support layer in the thickness direction; and A conductor layer disposed on one side of the insulating layer in the thickness direction. The conductor layer comprises: A grounding pattern having a grounding terminal electrically connected to the metal support layer; A wiring pattern having terminal portions that are insulated from the metal support layer; as well as The remaining portion of the grounding conductor is electrically connected to the terminal portion of the wiring pattern, but not connected to the grounding pattern itself, and is insulated from the metal support layer. The insulating layer has a through hole extending through the thickness direction. The remaining portion of the grounding conductor has a continuous opening that surrounds the through hole.

2. The wiring circuit board according to claim 1, characterized in that, The opening is connected to the through hole.

3. A wiring circuit board, characterized in that, The wiring circuit board has the following features: Metal support layer; An insulating layer disposed on one side of the metal support layer in the thickness direction; and A conductor layer disposed on one side of the insulation layer in the thickness direction, having a terminal portion and a residual portion of a grounding wire electrically connected to the terminal portion. The insulating layer has a through hole extending through the thickness direction. The remaining portion of the grounding conductor has: An opening that is continuous in a manner that surrounds the through hole; A conductive portion, which is disposed within the opening and fills the through hole; as well as The peripheral portion defines the opening and is located at a distance from the conductive portion.

4. A method for manufacturing a wiring circuit board, characterized in that, The manufacturing method of the wiring circuit board includes: The process of preparing the metal support layer; The process of forming an insulating layer on one side of the metal support layer in the thickness direction, the insulating layer having a through hole extending through in the thickness direction; The process of forming a conductor layer, the conductor layer including a grounding pattern and a wiring pattern, the wiring pattern having a terminal portion disposed on one side of the thickness direction of the insulating layer and a grounding wire electrically connecting the terminal portion and the metal support layer; The process of performing chemical plating on the conductor layer; and The process of removing a portion of the grounding wire to form a residual portion of the grounding wire, thereby insulating the terminal portion and the metal support layer. The remaining portion of the grounding conductor has a continuous opening that surrounds the through hole.

5. The method for manufacturing a wiring circuit board according to claim 4, characterized in that, In the process of removing the local part of the grounding wire, the opening is made to connect with the through hole.

6. The method for manufacturing a wiring circuit board according to claim 4, characterized in that, In the process of removing a portion of the grounding wire, a conductive portion and a peripheral portion are formed. The conductive portion is disposed within the opening and fills the through hole. The peripheral portion divides the opening and is located at a position spaced apart from the conductive portion.

7. The method for manufacturing a wiring circuit board according to claim 4, characterized in that, The manufacturing method of the wiring circuit board also includes: A process of forming a seed film on one side of the insulating layer in the thickness direction and on the side of the metal support layer exposed from the insulating layer in the thickness direction, after the process of forming the insulating layer and before the process of forming the conductor layer; A process of removing the seed film exposed from the conductor layer after the process of forming the conductor layer and before the process of electroless plating; and After the process of removing the local portion of the grounding wire, a process of removing the seed film exposed by the removal of the grounding wire.

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