Wiring circuit board

Abstract

A wiring circuit board 1 has a flexible part 3A and a support part 2A that supports the flexible part 3A. The wiring circuit board 1 comprises a first insulating layer 11, a conductor pattern 12, and a metal support layer 14. The flexible part 3A is provided with a portion of the first insulating layer 11, a portion of the conductor pattern 12, a portion of the metal support layer 14, and a resin layer 15 that covers the metal support layer 14.

Description

Wiring circuit board

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

[0002] Conventionally, a wiring circuit board has been proposed that includes a plurality of wiring bodies arranged in parallel at intervals from each other, a first connecting body that connects one end portions of the plurality of wiring bodies, and a second connecting body that connects the other end portions of the plurality of wiring bodies (see, for example, Patent Document 1 below). The wiring body includes a metal-based support layer, a base insulating layer disposed on one surface in the thickness direction of the metal-based support layer, and a wiring (main wiring portion) disposed on one surface in the thickness direction of the base insulating layer.

[0003] Japanese Patent Application Laid-Open No. 2019-212656

[0004] In the wiring circuit board as described in Patent Document 1, when a first element is mounted on the first connecting body and a second element is mounted on the second connecting body, the plurality of wiring bodies are disposed between the first element and the second element in a flexible state.

[0005] Therefore, if the wiring body bends and comes into contact with an adjacent wiring body or surrounding components, there is a possibility that dust is generated from the metal-based support layer of the wiring body.

[0006] The present invention provides a wiring circuit board capable of suppressing dust generation from the metal support layer of the flexible portion.

[0007] The present invention [1] includes a flexible portion and a support portion that supports the flexible portion, and includes an insulating layer, a conductor pattern disposed on one side of the insulating layer in the thickness direction of the insulating layer, and a metal support layer disposed on the other side of the insulating layer in the thickness direction, wherein the flexible portion includes a part of the insulating layer, a part of the conductor pattern, a part of the metal support layer, and a resin layer that covers the metal support layer.

[0008] According to such a configuration, the metal support layer of the flexible portion is covered with a resin layer.

[0009] Therefore, even if the flexible portion bends and comes into contact with surrounding components, it is possible to suppress the metal support layer of the flexible portion from coming into contact with surrounding components by the resin layer.

[0010] This suppresses dust generation from the metal support layer of the flexible section.

[0011] The present invention [2] includes the wiring circuit board of [1] above, wherein the support portion comprises a part of the insulating layer, a part of the conductor pattern, and a part of the metal support layer, and the resin layer does not cover the metal support layer of the support portion.

[0012] With this configuration, the metal support layer of the support portion that is not covered by the resin layer can be used for joining or electrical connection with surrounding parts.

[0013] The present invention [3] includes a wiring circuit board according to [1] or [2], wherein the conductor pattern comprises a first terminal located on the opposite side of the metal support layer from the insulating layer in the thickness direction and insulated from the metal support layer, and wiring located on the opposite side of the metal support layer from the insulating layer in the thickness direction, connected to the first terminal, and insulated from the metal support layer, and at least a portion of the wiring is located on the flexible portion.

[0014] The present invention [4] includes the wiring circuit board of [3], wherein the conductor pattern is arranged in the thickness direction on the opposite side of the metal support layer from the insulating layer and has a second terminal electrically connected to the metal support layer.

[0015] With this configuration, even if the flexible part bends and comes into contact with surrounding components when the second terminal is electrically connected to the metal support layer, the resin layer can prevent the metal support layer of the flexible part from short-circuiting with the surrounding components.

[0016] The present invention [5] includes any one of the wiring circuit boards described in [1] to [4] above, wherein the wiring circuit board does not have terminals that can be electrically connected to electronic components on the same side as the metal support layer with respect to the insulating layer in the thickness direction.

[0017] The present invention [6] includes any one of the wiring circuit boards described in [1] to [5] above, wherein the thickness of the resin layer in the width direction of the flexible portion is thinner than the width of the metal support layer of the flexible portion.

[0018] This configuration prevents the resin layer from excessively increasing the width of the flexible section.

[0019] The present invention [7] includes any one of the wiring circuit boards described in [1] to [6] above, wherein, in the thickness direction, the thickness of the resin layer is thinner than the thickness of the metal support layer of the flexible portion.

[0020] This configuration prevents the resin layer from excessively increasing the thickness of the flexible section.

[0021] The present invention [8] includes any one of the above [1] to [7] wiring circuit boards having a plurality of the flexible parts.

[0022] This configuration allows for increased flexibility in circuit design by utilizing multiple flexible components.

[0023] The present invention [9] includes any one of the above [1] to [8] wiring circuit boards, wherein the metal support layers of each of the plurality of flexible parts are spaced apart from each other in the width direction of the flexible part, and the thickness of the resin layer in the width direction is thinner than the spacing.

[0024] This configuration prevents the width of the flexible section from increasing excessively due to the resin layer, while also ensuring adequate spacing between the multiple flexible sections.

[0025] The present invention

[10] includes any one of the above [1] to [9] wiring circuit boards wherein the material of the resin layer is different from the material of the insulating layer.

[0026] The present invention

[11] includes any one of the wiring circuit boards described in [1] to

[10] above, further comprising a second flexible portion which does not have the insulating layer and the conductor pattern, but comprises the metal support layer and the resin layer.

[0027] With this configuration, by providing a second flexible section without a conductor pattern in addition to the flexible section with a conductor pattern, the design flexibility of the wiring circuit board can be improved.

[0028] Furthermore, in the case of the second flexible section, similar to the flexible section, the resin layer can prevent the metal support layer from coming into contact with surrounding components.

[0029] This also suppresses dust generation from the metal support layer of the second flexible section.

[0030] The present invention

[12] includes the wiring circuit board of

[11] in which the resin layer covers both sides of the metal support layer in the thickness direction and both sides of the metal support layer in the width direction of the second flexible portion.

[0031] With this configuration, dust generation from the metal support layer of the second flexible section can be reliably suppressed.

[0032] According to the wiring circuit board of the present invention, dust generation from the flexible part can be suppressed.

[0033] Figure 1 is a plan view showing a first embodiment of the wiring circuit board of the present invention. Note that the second insulating layer is omitted in Figure 1. Figure 2A is a cross-sectional view taken along line A-A of the wiring circuit board shown in Figure 1. Figure 2B is a cross-sectional view taken along line B-B of the wiring circuit board shown in Figure 1. Figure 3 is a cross-sectional view taken along line C-C of the wiring circuit board shown in Figure 1. Figures 4A to 4C are process diagrams showing the manufacturing method of the wiring circuit board. Figure 4A shows the first insulating layer formation process. Figure 4B shows the conductor pattern formation process. Figure 4C shows the second insulating layer formation process. Figures 5A to 5B are process diagrams showing the manufacturing method of the wiring circuit board, following Figure 4C. Figure 5A shows the outline processing process. Figure 5B shows the resin layer formation process. Figures 6A to 6G are explanatory diagrams illustrating modified example (1). Figure 7 is a plan view of the wiring circuit board of modified example (2). Figure 8 is a cross-sectional view taken along line D-D of the wiring circuit board shown in Figure 7. Figure 9 is a plan view of the wiring circuit board of modified example (3). Figure 10A is a cross-sectional view taken along line E-E of the wiring circuit board shown in Figure 9. Figure 10B is a cross-sectional view taken along line F-F of the wiring circuit board shown in Figure 9. Figure 11 is a plan view of the wiring circuit board of modification (4). Figure 12A is a cross-sectional view taken along line G-G of the wiring circuit board shown in Figure 11. Figure 12B is a cross-sectional view taken along line H-H of the wiring circuit board shown in Figure 11. Figure 13 is a plan view of the wiring circuit board of modification (5). Figure 14A is a cross-sectional view taken along line I-I of the wiring circuit board shown in Figure 13. Figure 14B is a cross-sectional view taken along line J-J of the wiring circuit board shown in Figure 13. Figure 15 is a plan view of the wiring circuit board of modification (6). Figure 16 is a cross-sectional view taken along line K-K of the wiring circuit board shown in Figure 15. Figure 17 is a plan view of a circuit-equipped suspension board as a second embodiment of the wiring circuit board of the present invention. Note that the second insulating layer is omitted in Figure 17. Figure 18A is a cross-sectional view taken along line L-L of the circuit-equipped suspension board shown in Figure 17. Figure 18B is an M-M cross-sectional view of the circuit-equipped suspension board shown in Figure 17.

[0034] 1. First Embodiment The wiring circuit board 1 as the first embodiment of the wiring circuit board of the present invention will be described.

[0035] As shown in Figure 1, the wiring circuit board 1 has a plurality of support parts 2A, 2B and a plurality of flexible parts 3A, 3B.

[0036] Support parts 2A and 2B are arranged at a distance from each other in the first direction. Each of the support parts 2A and 2B extends in the second direction. The second direction is perpendicular to the first direction. The shapes of the support parts 2A and 2B are not limited. Support part 2A supports one end of each of the flexible parts 3A and 3B. Terminals 121A and 121B of the conductor pattern 12, described later, may be arranged on support part 2A. In other words, support part 2A may comprise a part of the conductor pattern 12. Support part 2B supports the other end of each of the flexible parts 3A and 3B. Terminals 122A and 122B of the conductor pattern 12, described later, may be arranged on support part 2B.

[0037] The flexible parts 3A and 3B are flexible parts in the mounted state of the wiring circuit board 1 (see Figure 3, described later). The flexible parts 3A and 3B are positioned between the support parts 2A and 2B in the first direction. At least a portion of the wiring 123A of the conductor pattern 12, described later, is positioned on the flexible part 3A. In other words, the flexible part 3A comprises a portion of the conductor pattern 12. The flexible part 3A has a width in the width direction of the wiring 123A and extends in the direction in which the wiring 123A extends. In this embodiment, the direction in which the wiring 123A extends is the same as the first direction, and the width direction of the wiring 123A is the same as the second direction. Note that the direction in which the wiring 123A extends may be different from the first direction. Also, the width direction of the wiring 123A may be different from the second direction. At least a portion of the wiring 123B of the conductor pattern 12, described later, is positioned on the flexible part 3B. The flexible section 3B has a width in the width direction of the wiring 123B and extends in the direction in which the wiring 123B extends. The flexible section 3B extends in the same direction as the flexible section 3A. One end of each of the flexible sections 3A and 3B is connected to the support section 2A. The other end of each of the flexible sections 3A and 3B is connected to the support section 2B. The shape of each of the flexible sections 3A and 3B is not limited. Each of the flexible sections 3A and 3B may be straight or curved. The length of each of the flexible sections 3A and 3B may be longer than the distance between the support section 2A and the support section 2B in the first direction. The flexible sections 3A and 3B are aligned in the second direction. In the second direction, the flexible section 3B is positioned at a distance from the flexible section 3A.

[0038] As shown in Figures 2A and 2B, the wiring circuit board 1 comprises a first insulating layer 11 as an example of an insulating layer, a conductor pattern 12, a second insulating layer 13, a metal support layer 14, and a resin layer 15.

[0039] (1) The first insulating layer 11 is arranged in the support parts 2A and 2B and the flexible parts 3A and 3B. In other words, the support parts 2A and 2B comprise a portion of the first insulating layer 11. The flexible parts 3A and 3B also comprise a portion of the first insulating layer 11.

[0040] The first insulating layer 11 is disposed on one side of the metal support layer 14 in the thickness direction of the first insulating layer 11. The first insulating layer 11 is disposed on one side surface of the metal support layer 14 in the thickness direction. The first insulating layer 11 is disposed between the metal support layer 14 and the conductor pattern 12 in the thickness direction. The first insulating layer 11 insulates the metal support layer 14 from the conductor pattern 12. The first insulating layer 11 is made of resin. Examples of the resin include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0041] (2) Conductor Pattern The conductor pattern 12 is disposed on one side of the first insulating layer 11 in the thickness direction. The conductor pattern 12 is disposed on one side surface of the first insulating layer 11 in the thickness direction. The conductor pattern 12 is disposed on the opposite side of the metal support layer 14 with respect to the first insulating layer 11 in the thickness direction. The conductor pattern 12 is made of metal. Examples of the metal include copper, silver, gold, iron, aluminum, chromium, and their alloys. In order to obtain good electrical characteristics, preferably, copper is mentioned as the metal.

[0042] Note that the conductor pattern 12 may include a seed layer described later. The seed layer is disposed on one side surface of the first insulating layer 11 in the thickness direction. The seed layer protects the conductor pattern 12.

[0043] As shown in FIG. 1, the conductor pattern 12 includes a plurality of terminals 121A, 121B, a plurality of terminals 122A, 122B, and a plurality of wirings 123A, 123B. The terminals 121A, 121B are an example of the first terminal.

[0044] The terminals 121A, 121B are disposed on the support portion 2A. Each of the terminals 121A, 121B has a square land shape. As shown in FIG. 2A, the terminals 121A, 121B are disposed on the opposite side of the metal support layer 14 with respect to the first insulating layer 11 in the thickness direction. The terminals 121A, 121B are insulated from the metal support layer 14 by the first insulating layer 11.

[0045] As shown in FIG. 1, terminals 122A and 122B are disposed on the support portion 2B. Each of the terminals 122A and 122B has a square land shape. Similar to the terminals 121A and 121B, the terminals 122A and 122B are disposed on the opposite side of the metal support layer 14 with respect to the first insulating layer 11 in the thickness direction. The terminals 122A and 122B are insulated from the metal support layer 14 by the first insulating layer 11.

[0046] The wiring circuit board 1 does not have terminals that can be electrically connected to electronic components on the same side as the metal support layer 14 (i.e., the other side in the thickness direction) with respect to the first insulating layer 11 in the thickness direction.

[0047] The wiring 123A electrically connects the terminal 121A and the terminal 122A. One end portion of the wiring 123A is connected to the terminal 121A. The other end portion of the wiring 123A is connected to the terminal 122A. At least a part of the wiring 123A is disposed in the flexible portion 3A. One end portion of the wiring 123A may be disposed in the support portion 2A. The other end portion of the wiring 123A may be disposed in the support portion 2B.

[0048] The wiring 123B electrically connects the terminal 121B and the terminal 122B. One end portion of the wiring 123B is connected to the terminal 121B. The other end portion of the wiring 123B is connected to the terminal 122B. At least a part of the wiring 123B is disposed in the flexible portion 3B. One end portion of the wiring 123B may be disposed in the support portion 2A. The other end portion of the wiring 123B may be disposed in the support portion 2B.

[0049] As shown in FIG. 2B, each of the wirings 123A and 123B is disposed on the opposite side of the metal support layer 14 with respect to the first insulating layer 11 in the thickness direction. Each of the wirings 123A and 123B is insulated from the metal support layer 14 by the first insulating layer 11.

[0050] (3) Second insulating layer The second insulating layer 13 is arranged on one side of the first insulating layer 11 in the thickness direction. The second insulating layer 13 is arranged on one side surface of the first insulating layer 11 in the thickness direction. The second insulating layer 13 covers all the wiring 123A, 123B. The second insulating layer 13 does not cover the terminals 121A, 121B, 122A, 122B. The second insulating layer 13 is made of resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0051] (4) Metal support layer As shown in Figures 2A and 2B, the metal support layer 14 is arranged in the support sections 2A and 2B and the flexible sections 3A and 3B. That is, the support section 2A comprises a part of the metal support layer 14. The flexible section 3A also comprises a part of the metal support layer 14. The metal support layer 14 of each of the flexible sections 3A and 3B is continuous with the metal support layer 14 of each of the support sections 2A and 2B.

[0052] The metal support layer 14 is positioned on the other side of the first insulating layer 11 in the thickness direction. The metal support layer 14 supports the first insulating layer 11, the conductor pattern 12, and the second insulating layer 13. The metal support layer 14 is made of metal. Examples of materials for the metal support layer 14 include copper, nickel, cobalt, iron, and alloys thereof. Examples of alloys include stainless steel and copper alloys. Preferably, the material for the metal support layer 14 is a copper alloy.

[0053] The thickness T1 of the metal support layer 14 is, for example, 10 μm to 300 μm, preferably 10 μm to 200 μm.

[0054] The width W1 of the metal support layer 14 of the flexible portion 3A is, for example, 5 μm to 500 μm, preferably 10 μm to 450 μm, and more preferably 20 μm to 450 μm.

[0055] In the flexible portion 3A, the ratio of the thickness T1 of the metal support layer 14 to the width W1 of the metal support layer 14 (T1 / W1) is, for example, 0.1 or more, preferably 3.0 or more. When the ratio (T1 / W1) is equal to or greater than the above lower limit, the rigidity of the flexible portion 3A in the thickness direction can be ensured. The ratio (T1 / W1) is, for example, 30.0 or less, preferably 10.0 or less. The ratio (T1 / W1) may be, for example, 0.1 to 30.0, or 3.0 to 10.0.

[0056] The metal support layers 14 of the flexible sections 3A and 3B are arranged in the width direction with a gap D between them.

[0057] The interval D is, for example, 100 μm to 700 μm, preferably 150 μm to 300 μm.

[0058] (5) Resin layer The resin layer 15 is arranged in the flexible parts 3A and 3B. That is, each of the flexible parts 3A and 3B is provided with the resin layer 15. In each of the flexible parts 3A and 3B, the resin layer 15 covers at least a part of the metal support layer 14.

[0059] More specifically, as shown in Figure 2B, in each of the flexible parts 3A and 3B, the resin layer 15 covers the other surface of the metal support layer 14 in the thickness direction and both surfaces of the metal support layer 14 in the width direction. Preferably, in each of the flexible parts 3A and 3B, the resin layer 15 covers the entire other surface of the metal support layer 14 in the thickness direction and both surfaces of the metal support layer 14 in the width direction. The corners C of the resin layer 15 may be arc-shaped. In each of the flexible parts 3A and 3B, the resin layer 15 does not need to cover a part of the metal support layer 14.

[0060] As shown in Figure 2A, the resin layer 15 does not cover at least a portion of the metal support layer 14 of the support parts 2A and 2B. For example, the resin layer 15 does not cover all of the metal support layer 14 of the support parts 2A and 2B. The resin layer 15 may cover a portion of the metal support layer 14 of the support parts 2A and 2B.

[0061] The material of the resin layer 15 may be different from the material of the first insulating layer 11. The material of the resin layer 15 may be the same as the material of the first insulating layer 11. Examples of materials for the resin layer 15 include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include acrylic resins. Examples of thermosetting resins include epoxy resins, polyamides, polyimides, and urethane resins. The resin layer 15 may be a cured product of a photosensitive resin. Examples of photosensitive resins include photosensitive polyimides.

[0062] The resin layer 15 may contain a base resin and a filler. Examples of the base resin include the material of the resin layer 15 described above. Examples of the filler include inorganic fillers and organic fillers. Examples of inorganic fillers include layered silicate minerals, mica, wollastonite, saponite, montmorillonite, smectite, xonotlite, talc, calcium carbonate, natural zeolite, synthetic zeolite, carbon, graphite, silicon carbide, glass fiber, carbon fiber, potassium titanate, talc, graphite, silica, carbon black, clay, zinc oxide, titanium oxide, tourmaline, barium sulfate, magnesium carbonate, glass, alumina, aluminum, aluminum hydroxide, iron, asbestos, titanium oxide, iron oxide, diatomaceous earth, zeolite, ferrite, heavy calcium carbonate, light calcium carbonate, aluminum hydroxide, magnesium hydroxide Examples include sium, sepiolite, gypsum, cement, converter slag powder, shirasu powder, glass powder, glass flakes, calcium silicate, vermiculite, kaolinite, vermiculite, molybdenum disulfide, sericite, boron nitride, titanium dioxide, silicon dioxide, strontium titanate, barite, precipitated barium sulfate, magnesium slicate, aluminum silicate, stainless steel flakes, nickel flakes, borax, kiln ash, dolomite, iron powder, lead powder, copper powder, silica sand, kaolin, chalk, clay minerals, dolomite, quartz, bentonite, fly ash, perlite, zirconia, barium titanate, and halloysite. Examples of organic fillers include styrene-acrylic copolymer oligomers, low molecular weight nylon 66, ethylene terephthalic acid oligomers, urethane oligomers, cyclic amines, Ketjenblack carbon, flake graphite, wood chips, rice bran, hollow resin particles, foaming agents made of resin, orthophosphate ester compounds, aromatic secondary amine compounds, halogenated acid ester compounds, benzothiazyl compounds, benzotriazole compounds, diphenyl acrylate compounds, polyethylene powder, polystyrene powder, ethylene-vinyl acetate resin powder, polyurethane resin powder, polyamide resin powder, phenol-impregnated paper powder, polymer fibers, vulcanized rubber particles, crosslinked rubber particles, carbon fibers, fibrous fillers (e.g., cotton flocks), hollow pigments, and plastic fillers.

[0063] As shown in Figure 2B, in the width direction, the thickness T11 of the resin layer 15 is thinner than the width W1 of the metal support layer 14 of the flexible part 3A. Note that if the thickness T11 of the resin layer 15 covering the side surface of the metal support layer 14 is non-uniform in the thickness direction, "thickness T11" is the average value of the thickness T11 of the thickest part of the resin layer 15 covering the side surface of the metal support layer 14 and the thickness T11 of the thinnest part of the resin layer 15 covering the side surface of the metal support layer 14. The ratio of the thickness T11 of the resin layer 15 in the width direction to the width W1 of the metal support layer 14 (T11 / W1) is, for example, 0.99 or less, preferably 0.90 or less, and for example, 0.002 or more, preferably 0.005 or more. In the width direction, the thickness T11 of the resin layer 15 is thinner than the distance D between the metal support layer 14 of the flexible part 3A and the metal support layer 14 of the flexible part 3B. The ratio of the thickness T11 of the resin layer 15 in the width direction to the spacing D (T11 / D) is, for example, 0.5 or less, preferably 0.3 or less, and for example, 0.001 or more, preferably 0.003 or more.

[0064] The thickness T11 of the resin layer 15 in the width direction is, for example, 1 μm to 50 μm, preferably 10 μm to 35 μm.

[0065] In the thickness direction, the thickness T12 of the resin layer 15 is thinner than the thickness T1 of the metal support layer 14 of the flexible portion 3A. If the thickness T12 of the resin layer 15 covering the bottom surface (the other surface in the thickness direction) of the metal support layer 14 is non-uniform in the width direction, then "thickness T12" is the average value of the thickness T12 of the thickest part of the resin layer 15 covering the bottom surface of the metal support layer 14 and the thickness T12 of the thinnest part of the resin layer 15 covering the bottom surface of the metal support layer 14. The ratio of the thickness T12 of the resin layer 15 in the thickness direction to the thickness T1 of the metal support layer 14 (T12 / T1) is, for example, 0.99 or less, preferably 0.7 or less, and for example, 0.0001 or more, preferably 0.005 or more.

[0066] The thickness T12 of the resin layer 15 in the thickness direction is, for example, 1 μm to 50 μm, preferably 2 μm to 25 μm.

[0067] 2. Mounting status of the wiring circuit board Next, the mounting status of the wiring circuit board 1 will be described.

[0068] As shown in Figure 3, the wiring circuit board 1 is used for the electrical connection between the first electronic component P1 and the second electronic component P2. For example, the first electronic component P1 is mounted on the support portion 2A. The support portion 2B is fixed to the second electronic component P2. The flexible portions 3A and 3B are positioned between the first electronic component P1 and the second electronic component P2. The first electronic component P1 is movable relative to the second electronic component P2. When the first electronic component P1 moves relative to the second electronic component P2, the flexible portions 3A and 3B are elastically deformable.

[0069] 3. Manufacturing Method of Wired Circuit Board Next, the manufacturing method of the wired circuit board 1 will be described.

[0070] The manufacturing method for the wiring circuit board 1 includes a first insulating layer formation step (see Figure 4A), a conductor pattern formation step (see Figure 4B), a second insulating layer formation step (see Figure 4C), an outer shape processing step (see Figure 5A), and a resin layer formation step (see Figure 5B).

[0071] (1) First insulating layer formation process As shown in Figure 4A, in the first insulating layer formation process, a first insulating layer 11 is formed on one side surface of the metal substrate M.

[0072] More specifically, in the first insulating layer formation step, a photosensitive resin solution (varnish) is applied to the substrate M and dried to form a photosensitive resin coating. Next, the photosensitive resin coating is exposed to light and developed. This gives rise to the first insulating layer 11.

[0073] (2) Conductor pattern formation process Next, as shown in Figure 4B, in the conductor pattern formation process, a conductor pattern 12 is formed on the first insulating layer 11.

[0074] In more detail, first, a seed layer is formed in the thickness direction on one side surface of the first insulating layer 11 and on one side surface of the substrate M. The seed layer is formed, for example, by sputtering. Examples of materials for the seed layer include chromium, copper, nickel, titanium, and alloys thereof.

[0075] Next, the seed layer is coated with a plating resist.

[0076] Next, the plating resist is exposed and developed. This removes the plating resist in the areas where the conductor pattern 12 will be formed, exposing the seed layer in those areas. On the other hand, the plating resist remains in the areas where the conductor pattern 12 will not be formed.

[0077] Next, a conductive pattern 12 is formed on the exposed seed layer by electroplating. After the electroplating is completed, the plating resist is peeled off, and the seed layer exposed by the peeling off of the plating resist is removed by etching.

[0078] As a result, a conductor pattern 12 is formed on the first insulating layer 11.

[0079] (3) Second insulating layer formation process Next, as shown in Figure 4C, in the second insulating layer formation process, the second insulating layer 13 is formed on the first insulating layer 11.

[0080] More specifically, in the second insulating layer formation step, first, a photosensitive resin solution (varnish) is applied to the substrate M, the first insulating layer 11, and the conductor pattern 12 and dried to form a photosensitive resin coating.

[0081] Next, the photosensitive resin coating is exposed to light and developed. This forms a second insulating layer 13 on the first insulating layer 11.

[0082] (4) Outer shape processing process Next, as shown in Figure 5A, in the outer shape processing process, the base material M is etched to form a metal support layer 14.

[0083] (5) Resin layer formation process Next, as shown in Figure 5B, in the resin layer formation process, a resin layer 15 is formed on the surface of the metal support layer 14. Specifically, in the resin layer formation process, a resin layer 15 is formed on the other side surface of the metal support layer 14 in the thickness direction, and on both sides of the metal support layer 14 in the width direction.

[0084] Methods for forming the resin layer 15 include, for example, electrodeposition coating, painting, and dipping. Preferably, the resin layer 15 is formed by electrodeposition coating.

[0085] The above-described wiring circuit board 1 is obtained.

[0086] 4. Effects (1) In the wiring circuit board 1, as shown in Figure 2B, the metal support layer 14 of the flexible part 3A is covered with a resin layer 15.

[0087] Therefore, even if the flexible part 3A bends and comes into contact with surrounding parts, the resin layer 15 can prevent the metal support layer 14 of the flexible part 3A from coming into contact with the surrounding parts.

[0088] This makes it possible to suppress dust generation from the metal support layer 14 of the flexible section 3A.

[0089] (2) According to the wiring circuit board 1, as shown in Figure 3, the resin layer 15 does not cover the metal support layer 14 of the support portion 2A.

[0090] Therefore, the metal support layer 14 of the support portion 2A, which is not covered by the resin layer 15, can be used for joining or electrical connection with surrounding parts.

[0091] (3) According to the wiring circuit board 1, as shown in Figure 2B, in the width direction, the thickness T11 of the resin layer 15 is thinner than the width W1 of the metal support layer 14 of the flexible part 3A.

[0092] Therefore, the resin layer 15 can prevent the width of the flexible portion 3A from increasing excessively.

[0093] (4) According to the wiring circuit board 1, as shown in Figure 2B, in the thickness direction, the thickness T12 of the resin layer 15 is thinner than the thickness T1 of the metal support layer 14 of the flexible part 3A.

[0094] Therefore, it is possible to prevent the thickness of the flexible portion 3A from increasing excessively due to the resin layer 15.

[0095] (5) The wiring circuit board 1 has a plurality of flexible parts 3A, 3B as shown in Figure 1.

[0096] Therefore, by utilizing multiple flexible parts 3A and 3B, the degree of freedom in circuit design can be improved.

[0097] (6) According to the wiring circuit board 1, as shown in Figure 2B, the thickness T11 of the resin layer 15 in the width direction is thinner than the distance D between the metal support layer 14 of the flexible part 3A and the metal support layer 14 of the flexible part 3B.

[0098] Therefore, the resin layer 15 prevents the width of the flexible portion 3A from increasing excessively, and ensures that the spacing between each of the multiple flexible portions 3A and 3B is maintained.

[0099] 5. Modified Examples Next, modified examples will be described. In the modified examples, the same reference numerals are used for components similar to those in the first embodiment described above, and their descriptions are omitted.

[0100] (1) The corner C of the resin layer 15 is not limited to an arc shape. It may be rectangular, as shown in Figure 6A.

[0101] Furthermore, as shown in Figures 6B to 6D, the resin layer 15 may cover the other surface of the first insulating layer 11 in the thickness direction. In this case, the portion 15A of the resin layer 15 that covers the first insulating layer 11 may be arc-shaped (see Figure 6B), rectangular (see Figure 6C), or tapered (see Figure 6D), becoming thicker from the other side in the thickness direction towards one side in the thickness direction.

[0102] Furthermore, as described above, the resin layer 15 does not need to cover a portion of the metal support layer 14 of the flexible portion 3A.

[0103] As shown in Figure 6E, the resin layer 15 may cover all of both sides of the metal support layer 14 of the flexible portion 3A in the width direction, but may not cover the other side surface of the metal support layer 14 of the flexible portion 3A in the thickness direction.

[0104] Furthermore, as shown in Figure 6F, the resin layer 15 may cover the entire other surface of the metal support layer 14 of the flexible portion 3A in the thickness direction, and parts of both sides of the metal support layer 14 of the flexible portion 3A in the width direction.

[0105] Furthermore, as shown in Figure 6G, the resin layer 15 covers the other surface of the metal support layer 14 of the flexible portion 3A in the thickness direction, but does not need to cover all of both sides of the metal support layer 14 of the flexible portion 3A in the width direction.

[0106] These modifications also yield the same effects and advantages as those of the first embodiment described above.

[0107] (2) As shown in Figure 7, the conductor pattern 12 may also include terminals 121C and 122C in addition to the terminals 121A and 121B, terminals 122A and 122B and wiring 123A and 123B described above. Terminal 121C is an example of a second terminal. Terminal 121C is located on the support portion 2A. Terminal 122C is located on the support portion 2B. The first insulating layer 11 also has a plurality of through holes 111.

[0108] As shown in Figure 8, terminal 121C is positioned on the opposite side of the metal support layer 14 from the first insulating layer 11 in the thickness direction. Terminal 121C is electrically connected to the metal support layer 14 through the through hole 111 in the first insulating layer 11. Similarly, terminal 122C (see Figure 7) is also electrically connected to the metal support layer 14 through the through hole 111 in the first insulating layer 11.

[0109] With this modified configuration, even if the flexible parts 3A and 3B bend and come into contact with surrounding components when the terminal 121C is electrically connected to the metal support layer 14, the resin layer 15 can prevent the metal support layer 14 of the flexible parts 3A and 3B from short-circuiting with the surrounding components.

[0110] This modified example also provides the same effects and advantages as the first embodiment described above.

[0111] (3) As shown in Figure 9, the wiring circuit board 1 may further include a second flexible portion 3C. The second flexible portion 3C is positioned between the support portion 2A and the support portion 2B in the first direction. One end of the second flexible portion 3C is connected to the support portion 2A. The other end of the second flexible portion 3C is connected to the support portion 2B. The shape of the second flexible portion 3C is not limited. The second flexible portion 3C may be straight or curved. The length of the second flexible portion 3C may be longer than the distance between the support portion 2A and the support portion 2B in the first direction.

[0112] As shown in Figures 10A and 10B, the second flexible portion 3C may not have the first insulating layer 11 and the conductor pattern 12, but may have a metal support layer 14 and a resin layer 15. The metal support layer 14 of the second flexible portion 3C is continuous with the respective metal support layers 14 of the support portions 2A and 2B.

[0113] In the second flexible portion 3C, the resin layer 15 may cover both sides of the metal support layer 14 in the thickness direction and both sides of the metal support layer 14 in the width direction of the second flexible portion 3C. Preferably, in the second flexible portion 3C, the resin layer 15 covers all of both sides of the metal support layer 14 in the thickness direction and all of both sides of the metal support layer 14 in the width direction of the second flexible portion 3C. In addition, in the second flexible portion 3C, the resin layer 15 does not need to cover a part of the metal support layer 14.

[0114] This modified example also provides the same effects and advantages as the first embodiment described above.

[0115] Furthermore, according to this modified version, as shown in Figure 9, by providing a second flexible section 3C that does not have a conductor pattern 12, in addition to the flexible sections 3A and 3B that have a conductor pattern 12, the degree of design freedom for the wiring circuit board 1 can be improved.

[0116] Furthermore, in the case of the second flexible section 3C, similar to the flexible sections 3A and 3B, the resin layer 15 can prevent the metal support layer 14 from coming into contact with surrounding components.

[0117] This also suppresses dust generation from the metal support layer 14 of the second flexible section 3C.

[0118] Furthermore, according to this modified version, as shown in Figure 10B, in the second flexible portion 3C, the resin layer 15 covers both sides of the metal support layer 14 in the thickness direction and both sides of the metal support layer 14 in the width direction.

[0119] Therefore, dust generation from the metal support layer 14 of the second flexible section 3C can be reliably suppressed.

[0120] (4) As shown in Figure 11, the second flexible portion 3C may be positioned between the flexible portion 3A and the flexible portion 3B. In this case, one end of the second flexible portion 3C is connected to the flexible portion 3A. The other end of the second flexible portion 3C is connected to the flexible portion 3B. In this modified example, the shape of the second flexible portion 3C is not limited. The second flexible portion 3C may be straight or curved. The length of the second flexible portion 3C may be longer than the distance between the flexible portion 3A and the flexible portion 3B in the width direction.

[0121] Furthermore, each of the support parts 2A and 2B may be divided into multiple parts. For example, in the modified example shown in Figure 11, the support part 2A is divided into the same number of parts (2) as the number of terminals 121A and 121B. Similarly, the support part 2B is also divided into the same number of parts (2) as the number of terminals 122A and 122B.

[0122] Furthermore, as shown in Figures 12A and 12B, one side surface of the second flexible portion 3C in the thickness direction may be covered with the first insulating layer 11. In other words, the second flexible portion 3C may not have a conductor pattern 12, but instead comprise the first insulating layer 11, a metal support layer 14, and a resin layer 15.

[0123] This modified example also provides the same effects and advantages as the first embodiment described above.

[0124] (5) As shown in Figure 13, the flexible portion 3A may have a substantially U-shape. More specifically, the flexible portion 3A has a first portion 31A, a second portion 32A, and a third portion 33A. The first portion 31A extends in a direction intersecting the direction in which the support portions 2A and 2B are aligned (first direction). For example, in this modified example, the first portion 31A extends from the support portion 2A in a second direction. The second portion 32A extends from the support portion 2B in the same direction as the first portion 31A. The second portion 32A is positioned away from the first portion 31A in the first direction. The third portion 33A is positioned between the first portion 31A and the second portion 32A in the first direction. One end of the third portion 33A is connected to the first portion 31A. The other end of the third portion 33A is connected to the second portion 32A.

[0125] The second flexible portion 3C may be positioned between the first portion 31A and the second portion 32A. In this case, one end of the second flexible portion 3C is connected to the first portion 31A. The other end of the second flexible portion 3C is connected to the second portion 32A. In this modification, the shape of the second flexible portion 3C is not limited. The second flexible portion 3C may be straight or curved. The length of the second flexible portion 3C may be longer than the distance between the first portion 31A and the second portion 32A in the first direction.

[0126] In this modified example, as shown in Figures 14A and 14B, one side surface of the second flexible portion 3C in the thickness direction may be covered with the first insulating layer 11.

[0127] This modified example also provides the same effects and advantages as the first embodiment described above.

[0128] (6) As shown in Figure 15, the wiring circuit board 1 may further have outrigger sections 4A and 4B as an example of a second flexible section. Outrigger section 4A is arranged around support section 2A. Outrigger section 4B is arranged around support section 2B. Outrigger section 4B surrounds support section 2B.

[0129] As shown in Figure 16, the outrigger portion 4A does not have a first insulating layer 11 and a conductor pattern 20, but instead comprises a metal support layer 14 and a resin layer 15.

[0130] In the outrigger section 4A, the resin layer 15 covers both sides of the metal support layer 14 in the thickness direction and both sides of the metal support layer 14 in the width direction of the outrigger section 4A. Preferably, in the outrigger section 4A, the resin layer 15 covers all of both sides of the metal support layer 14 in the thickness direction and all of both sides of the metal support layer 14 in the width direction of the outrigger section 4A. In addition, in the outrigger section 4A, the resin layer 15 does not need to cover a part of the metal support layer 14.

[0131] This modified example also provides the same effects and advantages as the first embodiment described above.

[0132] 6. Second Embodiment Next, a suspension board 10 with a circuit, as a second embodiment of the wiring circuit board of the present invention, will be described. In the second embodiment, the same reference numerals are used for components as in the first embodiment described above, and their descriptions are omitted.

[0133] As shown in Figure 17, the circuit-equipped suspension board 10 can mount a slider S having a magnetic head. The circuit-equipped suspension board 10 is a component of the head gimbal assembly of a hard disk drive.

[0134] The circuit-equipped suspension board 10 has a mounting section 101 as an example of a flexible section, a wiring section 102 as an example of a support section, and an outrigger section 103 as an example of a second flexible section.

[0135] (1) Mounting section The mounting section 101 is located at the tip of the circuit-equipped suspension substrate 10. A slider S is mounted on the mounting section 101. The mounting section 101 is supported at the tip of the wiring section 102 by the outrigger section 103. The mounting section 101 extends in a third direction and a fourth direction. The third direction is the direction in which the magnetic head connection terminals 201A, 201B, 201C, and 201D are aligned. The fourth direction is perpendicular to the third direction. The third and fourth directions are perpendicular to the thickness direction of the first insulating layer 11 (see Figure 18A).

[0136] The mounting section 101 includes a part of the conductor pattern 20. More specifically, the conductor pattern 20 includes a plurality of magnetic head connection terminals 201A, 201B, 201C, 201D, a plurality of external connection terminals 202A, 202B, 202C, 202D (described later), and a plurality of wirings 203A, 203B, 203C, 203D (described later). The mounting section 101 includes a portion of each of the plurality of magnetic head connection terminals 201A, 201B, 201C, 201D and the plurality of wirings 203A, 203B, 203C, 203D.

[0137] The magnetic head connection terminals 201A, 201B, 201C, and 201D are aligned in a third direction. With the slider S mounted on the mounting section 101, the magnetic head connection terminals 201A, 201B, 201C, and 201D are connected to the magnetic head.

[0138] As shown in Figure 18A, the mounting portion 101 comprises a first insulating layer 11, the conductor pattern 20 described above, a second insulating layer 13, a metal support layer 14, and a resin layer 15. In other words, the circuit-equipped suspension substrate 10 comprises a first insulating layer 11, a conductor pattern 12, and a metal support layer 14, similar to the wiring circuit substrate 1 of the first embodiment.

[0139] In the second embodiment, in the mounting portion 101, the resin layer 15 covers at least a portion of the metal support layer 14. More specifically, in the mounting portion 101, the resin layer 15 covers the other surface of the metal support layer 14 in the thickness direction and the side surface of the metal support layer 14 (the side surface of the metal support layer 14 in the third direction and the side surface of the metal support layer 14 in the fourth direction). Preferably, in the mounting portion 101, the resin layer 15 covers the entire other surface of the metal support layer 14 in the thickness direction and the entire side surface of the metal support layer 14. In the mounting portion 101, the resin layer 15 does not need to cover a portion of the metal support layer 14.

[0140] (2) Wiring section As shown in Figure 17, the wiring section 102 extends in the fourth direction. The wiring section 102 has a belt shape. The wiring section 102 supports the outrigger section 103 and the mounting section 101.

[0141] The wiring section 102 includes a portion of the conductor pattern 20. More specifically, the wiring section 102 has a plurality of external connection terminals 202A, 202B, 202C, 202D and wiring 203A, 203B, 203C, 203D.

[0142] The external connection terminals 202A, 202B, 202C, and 202D are arranged in a predetermined direction with a distance between them. The direction in which the external connection terminals 202A, 202B, 202C, and 202D are arranged may be different from the third direction.

[0143] Wiring 203A electrically connects the magnetic head connection terminal 201A and the external connection terminal 202A. One end of wiring 203A is connected to the magnetic head connection terminal 201A. The other end of wiring 203A is connected to the external connection terminal 202A.

[0144] Wiring 203B electrically connects the magnetic head connection terminal 201B and the external connection terminal 202B. One end of wiring 203B is connected to the magnetic head connection terminal 201B. The other end of wiring 203B is connected to the external connection terminal 202B.

[0145] Wiring 203C electrically connects the magnetic head connection terminal 201C and the external connection terminal 202C. One end of wiring 203C is connected to the magnetic head connection terminal 201C. The other end of wiring 203C is connected to the external connection terminal 202C.

[0146] Wiring 203D electrically connects the magnetic head connection terminal 201D and the external connection terminal 202D. One end of wiring 203D is connected to the magnetic head connection terminal 201D. The other end of wiring 203D is connected to the external connection terminal 202D.

[0147] As shown in Figure 18B, the wiring section 102 comprises a first insulating layer 11, the conductor pattern 20 described above (see Figure 17), a second insulating layer 13, and a metal support layer 14.

[0148] In the second embodiment, the resin layer 15 does not cover at least a portion of the metal support layer 14 of the wiring section 102. For example, the resin layer 15 does not cover the entire metal support layer 14 of the wiring section 102. The resin layer 15 may cover a portion of the metal support layer 14 of the wiring section 102.

[0149] (3) Outrigger section As shown in Figure 17, the outrigger section 103 is arranged around the mounting section 101. The outrigger section 103 has a substantially frame shape.

[0150] As shown in Figures 18A and 18B, the outrigger portion 103 does not have a first insulating layer 11 and a conductor pattern 20, but instead comprises a metal support layer 14 and a resin layer 15.

[0151] In the outrigger portion 103, the resin layer 15 covers both sides of the metal support layer 14 in the thickness direction and both sides of the metal support layer 14 in the width direction of the outrigger portion 103. Preferably, in the outrigger portion 103, the resin layer 15 covers all of both sides of the metal support layer 14 in the thickness direction and all of both sides of the metal support layer 14 in the width direction of the outrigger portion 103. In the outrigger portion 103, the resin layer 15 does not need to cover a part of the metal support layer 14.

[0152] (4) Effects of the second embodiment The same effects as those of the first embodiment described above can be obtained in the second embodiment as well.

[0153] Furthermore, according to the second embodiment, as shown in Figures 18A and 18B, the metal support layer 14 of the mounting portion 101 is covered with a resin layer 15.

[0154] Therefore, even if the mounting section 101 comes into contact with surrounding components, the resin layer 15 can prevent the metal support layer 14 of the mounting section 101 from coming into contact with the surrounding components.

[0155] This makes it possible to suppress dust generation from the metal support layer 14 of the mounting section 101.

[0156] Furthermore, the metal support layer 14 of the outrigger section 103 is also covered with a resin layer 15, similar to the mounting section 101.

[0157] Therefore, even in the outrigger section 103, the resin layer 15 can prevent the metal support layer 14 from coming into contact with surrounding parts.

[0158] This also suppresses dust generation from the metal support layer 14 of the outrigger section 103.

[0159] Furthermore, in the outrigger section 103, the resin layer 15 covers both sides of the metal support layer 14 in the thickness direction and both sides of the metal support layer 14 in the width direction of the outrigger section 103.

[0160] Therefore, dust generation from the metal support layer 14 can be reliably suppressed in the outrigger section 103. While the above invention is provided as an illustrative embodiment, it is merely illustrative and should not be interpreted restrictively. Modifications of the invention that are obvious to those skilled in the art are included in the claims below.

[0161] The wiring circuit board of this disclosure can be used for connecting electronic components.

[0162] 1 Wiring circuit board 2A Support part 3A Flexible part 11 First insulating layer (example of insulating layer) 12 Conductor pattern 121A Terminal (first terminal) 123A Wiring 14 Metal support layer 15 Resin layer 121C Terminal (second terminal) 3C Second flexible part 10 Circuit suspension board (example of wiring circuit board) 101 Mounting part (example of flexible part) 102 Wiring part (example of support part) 103 Outrigger part (example of second flexible part) 20 Conductor pattern T1 Thickness of metal support layer W1 Width of metal support layer T11 Thickness of resin layer in width direction T12 Thickness of resin layer in thickness direction D Spacing between multiple flexible parts

Claims

1. A wiring circuit board having a flexible portion and a support portion that supports the flexible portion, comprising an insulating layer, a conductor pattern disposed on one side of the insulating layer in the thickness direction of the insulating layer, and a metal support layer disposed on the other side of the insulating layer in the thickness direction, wherein the flexible portion comprises a part of the insulating layer, a part of the conductor pattern, a part of the metal support layer, and a resin layer covering the metal support layer.

2. The wiring circuit board according to claim 1, wherein the support portion comprises a part of the insulating layer, a part of the conductor pattern, and a part of the metal support layer, and the resin layer does not cover the metal support layer of the support portion.

3. The wiring circuit board according to claim 1, wherein the conductor pattern comprises a first terminal located on the opposite side of the metal support layer from the insulating layer in the thickness direction and insulated from the metal support layer, and wiring located on the opposite side of the metal support layer from the insulating layer in the thickness direction, connected to the first terminal, and insulated from the metal support layer, and at least a portion of the wiring is located on the flexible portion.

4. The wiring circuit board according to claim 3, wherein the conductor pattern is arranged on the opposite side of the metal support layer from the insulating layer in the thickness direction and has a second terminal electrically connected to the metal support layer.

5. The wiring circuit board according to claim 1, wherein the wiring circuit board does not have terminals that can be electrically connected to electronic components on the same side as the metal support layer relative to the insulating layer in the thickness direction.

6. The wiring circuit board according to claim 1, wherein in the width direction of the flexible portion, the thickness of the resin layer is thinner than the width of the metal support layer of the flexible portion.

7. The wiring circuit board according to claim 1, wherein in the thickness direction, the thickness of the resin layer is thinner than the thickness of the metal support layer of the flexible portion.

8. The wiring circuit board according to claim 1, having a plurality of the flexible parts.

9. The wiring circuit board according to claim 1, wherein the metal support layers of each of the plurality of flexible parts are spaced apart from each other in the width direction of the flexible part, and the thickness of the resin layer in the width direction is thinner than the spacing between them.

10. The wiring circuit board according to claim 1, wherein the material of the resin layer is different from the material of the insulating layer.

11. The wiring circuit board according to claim 1, further comprising a second flexible portion which does not have the insulating layer and the conductor pattern, but which comprises the metal support layer and the resin layer.

12. The wiring circuit board according to claim 11, wherein in the second flexible portion, the resin layer covers both sides of the metal support layer in the thickness direction and both sides of the metal support layer in the width direction of the second flexible portion.

Images