Wiring circuit substrate and method for manufacturing the same

Abstract

The method for manufacturing a wiring circuit board (1) includes: a first step, in which a base insulating layer (7) is formed on one side of a metal sheet (25) in the thickness direction; a second step, in which a conductor layer (8) is formed on one side of the base insulating layer (7) such that the width (W3) of the wiring (16) is narrower than the width (W2) of the base (13) of the wiring body; and a third step, in which a cover insulating layer (9) is formed to cover the wiring (16). The width (W4) of the wiring body covering portion (19) is narrower than the width (W2) of the wiring body base (13), and a thickness direction side of the portion of the wiring body base (13) exposed from the wiring (16) is formed; and a fourth step, in which the metal sheet (25) is etched from both sides in the thickness direction, thereby forming a metal support layer (6) in such a way that the width (W1) of the wiring body metal portion (10) is narrower than the width (W2) of the wiring body base (13).

Description

Technical Field

[0001] This invention relates to wiring circuit boards and methods for manufacturing the same. Background Technology

[0002] Previously, a wiring circuit board was known, which included a metal support layer, a base insulating layer disposed on the metal support layer, wiring disposed on the base insulating layer, and a cover insulating layer disposed on the metal support layer to cover the base insulating layer and the wiring (see, for example, Patent Document 1 below).

[0003] In the wiring circuit board of Patent Document 1, the width of the covering insulating layer is greater than the width of the base insulating layer.

[0004] In addition, in Patent Document 1, a base insulating layer, wiring and a cover insulating layer are sequentially formed on a metal sheet, and then the metal sheet is etched to form a metal support layer.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-159899 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, from the perspective of production efficiency, etching is sometimes performed by having the etching solution contact the metal sheet from both the top and bottom sides. In this case, a resist coating is arranged on both the top and bottom surfaces of the metal sheet in a predetermined pattern.

[0010] Furthermore, depending on the purpose and application of the wiring circuit board, there is a requirement that the width of the metal support layer be narrower than the width of the base insulating layer.

[0011] Therefore, when a metal support layer of the aforementioned width is formed by etching metal sheets from both sides in the vertical direction, if the width of the covering insulating layer is wider than the width of the base insulating layer, as described in Patent Document 1 for a wiring circuit board, the end of the covering insulating layer in the width direction tends to protrude outwards compared to the end of the resist coating in the width direction. In this case, due to the covering insulating layer extending beyond the end of the resist coating, there is a defect that the metal support layer cannot be etched into the desired pattern.

[0012] The present invention provides a method for manufacturing a wiring circuit board capable of etching a metal sheet to form a metal support layer of a desired shape, and a wiring circuit board obtained by the manufacturing method.

[0013] Solution for solving the problem

[0014] The present invention (1) includes a method for manufacturing a wiring circuit board, wherein the method comprises: a first step, wherein a base insulating layer is formed on a side of a metal sheet in the thickness direction; a second step, wherein a wiring layer is formed on a side of the base insulating layer in the thickness direction such that the width of the wiring layer in a direction orthogonal to the extension direction and the thickness direction of the wiring layer is narrower than the width of the base insulating layer; a third step, wherein a cover insulating layer is formed on a side of the base insulating layer in the thickness direction of a portion of the base insulating layer exposed from the wiring layer such that the cover insulating layer covers the wiring layer and the width of the cover insulating layer is narrower than the width of the base insulating layer; and a fourth step, wherein the metal sheet is etched from both sides in the thickness direction to form a metal support layer such that the width of the metal support layer is narrower than the width of the base insulating layer.

[0015] In this manufacturing method, in the third step, a covering insulating layer is formed such that the width of the covering insulating layer is narrower than the width of the base insulating layer. Furthermore, in the fourth step, a metal support layer is formed such that the width of the metal support layer is narrower than the width of the base insulating layer.

[0016] Therefore, even if a first resist corresponding to the shape of the metal support layer is formed on one side of the metal sheet in the thickness direction, the first resist can cover the width-direction end of the cover insulating layer, which is narrower than the width of the base insulating layer. Thus, shape defects in the metal support layer caused by the width-direction end of the cover insulating layer protruding outwards compared to the width-direction end of the first resist can be suppressed, and a metal support layer of the desired shape can be formed.

[0017] The present invention (2) includes a method for manufacturing a wiring circuit board as described in (1), wherein, in the fourth step, the metal sheet is divided into a plurality of metal bodies spaced apart from each other in a cross section orthogonal to the extension direction; in the first step, a substrate insulating layer corresponding to each of the plurality of metal bodies is formed; in the second step, at least one wiring layer corresponding to each of the plurality of metal bodies is formed; and in the third step, a cover insulating layer corresponding to each of the plurality of metal bodies is formed.

[0018] In the fourth step of this manufacturing method, a base insulating layer, a wiring layer and a cover insulating layer corresponding to each of the multiple metal bodies are formed. Therefore, the external shape of each of the multiple metal bodies can be designed in correspondence with the base insulating layer, the wiring layer and the cover insulating layer.

[0019] The present invention (3) includes a method for manufacturing a wiring circuit board as described in (2), wherein the fourth step comprises: a fifth step in which a first resist is disposed on one side of the metal sheet in the thickness direction such that it covers the substrate insulating layer and the cover insulating layer corresponding to the metal body; a sixth step in which a second resist is disposed on the other side of the metal sheet in the thickness direction such that it overlaps with the first resist when projected in the thickness direction; and a seventh step in which the metal sheet is etched such that the overlapping portions of the metal sheet that overlap with the two ends in the width direction of the first resist and the second resist are etched sideways.

[0020] In this manufacturing method, since the metal sheet is etched by side etching the overlapping portion of the metal sheet that overlaps with the two ends of the first and second photoresists in the width direction, a metal support layer with a width narrower than the width of the substrate insulating layer can be reliably formed.

[0021] The present invention (4) includes a wiring circuit board, wherein the wiring circuit board comprises: a metal support layer; a substrate insulating layer disposed on a side of the metal support layer in the thickness direction; a wiring layer disposed on the side of the substrate insulating layer in the thickness direction, wherein the width of the wiring layer in a direction orthogonal to the extension direction of the wiring layer and the thickness direction is narrower than the width of the substrate insulating layer; and a cover insulating layer disposed on a side of the substrate insulating layer in the thickness direction to cover the wiring layer, wherein the width of the cover insulating layer is narrower than the width of the substrate insulating layer, and the width of the metal support layer is narrower than the width of the substrate insulating layer.

[0022] In this wiring circuit board, the width of the metal support layer and the width of the covering insulating layer are narrower than the width of the base insulating layer. That is, the width of the base insulating layer is the largest in their stacked portion. Therefore, it is possible to make the stacked portion have a narrower shape corresponding to the width of the base insulating layer.

[0023] The effects of the invention

[0024] Using the wiring circuit board and manufacturing method of the present invention, a metal support layer of desired shape can be formed. Attached Figure Description

[0025] [ Figure 1 ] Figure 1 A~ Figure 1 B represents an embodiment of a wiring circuit board obtained by the manufacturing method of the wiring circuit board of the present invention. Figure 1 A is the top view. Figure 1 B is a bottom view.

[0026] [ Figure 2 ] Figure 2 A~ Figure 2 B is Figure 1 A~ Figure 1 The cross-sectional view of the wiring circuit board shown in B. Figure 2 A is a frontal sectional view along the X-X line. Figure 2 B is a front sectional view along the Y-Y line.

[0027] [ Figure 3 ] Figure 3 A~ Figure 3 E is Figure 2 A is a process diagram of the manufacturing method of the wiring circuit board. Figure 3 A is the first step in forming the substrate insulating layer. Figure 3 B is the second step in forming the conductor layer. Figure 3 C is the third step in forming the covering insulating layer. Figure 3 D represents the fifth and sixth steps in the formation of the first and second resists. Figure 3 E is the 7th step in etching the metal sheet.

[0028] [ Figure 4 ] Figure 4 A~ Figure 4 B is the manufacturing process diagram in the comparative example. Figure 4 A represents the third process. Figure 4 B represents the 5th and 6th processes.

[0029] [ Figure 5 ] Figure 5 yes Figure 2 A cross-sectional view of a modified example of a wiring circuit board shown in Figure A (a configuration in which multiple wirings are provided relative to a single wiring body metal portion). Detailed Implementation

[0030] <One Implementation Method>

[0031] First, refer to Figure 1 A~ Figure 2 B will be used to describe one embodiment of the wiring circuit board of the present invention. Furthermore, in Figure 1 In A, the covering insulation layer 9, which will be described later, is omitted in order to clearly show the relative arrangement of the base insulating layer 7 and the conductor layer 8.

[0032] like Figure 1 A~ Figure 2 As shown in B, the wiring circuit board 1 has a predetermined thickness and a shape that extends along the length direction. The wiring circuit board 1 integrally includes a wiring body 2, a first connector 3, and a second connector 4.

[0033] Wiring body 2 extends along the length direction. Wiring body 2 is the middle part of the wiring circuit board 1 along the length direction. Multiple wiring bodies 2 are arranged at intervals in the width direction orthogonal to the thickness direction and the length direction. Each of the multiple wiring bodies 2 has a generally straight shape along the length direction.

[0034] The first connector 3 connects one end edge of the plurality of wiring elements 2 along their length direction in the width direction. The first connector 3 is one end of the wiring circuit board 1 along its length direction. The first connector 3, for example, has a generally rectangular shape when viewed from above.

[0035] The second connector 4 connects the other ends of the plurality of wiring bodies 2 along their length direction in the width direction. The second connector 4 is the other end of the wiring circuit board 1 along its length direction. The second connector 4, for example, has a generally rectangular shape when viewed from above.

[0036] Furthermore, the wiring circuit board 1 has an opening 5. The opening 5 is surrounded by a plurality of wiring bodies 2, a first connector 3, and a second connector 4. The opening 5 penetrates the wiring circuit board 1 in the thickness direction. The opening 5 has a generally rectangular shape when viewed from above. The opening 5 has a slit shape that separates the plurality of wiring bodies 2 in the width direction.

[0037] like Figure 2 A~ Figure 2 As shown in Figure B, the wiring circuit board 1 includes a metal support layer 6, a substrate insulating layer 7, a conductor layer 8, and a cover insulating layer 9 (in...). Figure 2 (Not shown in section B).

[0038] like Figure 1 As shown in B, the metal support layer 6 has a shape that is slightly smaller than (roughly similar in shape) than the outer shape of the wiring circuit board 1. The metal support layer 6 integrally has a wiring body metal portion 10 corresponding to the wiring body 2, a first connection metal portion 11 corresponding to the first connector 3, and a second connection metal portion 12 corresponding to the second connector 4.

[0039] like Figure 1 B and Figure 2 As shown in Figure A, the wiring metal portion 10 is provided corresponding to a plurality of wiring bodies 2. Each wiring metal portion 10 is narrower in shape (shorter in width direction) than each wiring body 2. Each wiring metal portion 10 has, for example, a shape that is approximately rectangular in cross-section. Furthermore, the cross-section is a surface obtained by cutting along a direction orthogonal to the direction in which the wiring body 2 extends (along the width and thickness directions), as follows. The wiring metal portion 10 is positioned closer to the inside of the width direction than the two ends of the wiring body 2 in the width direction.

[0040] like Figure 1 B and Figure 2 As shown in B, the first connecting metal part 11 is positioned inside the surface direction of the peripheral edge of the first connecting body 3.

[0041] like Figure 1 As shown in B, the second connecting metal part 12 is positioned inside the width direction from the peripheral edge of the second connecting body 4.

[0042] The material of the metal support layer 6 is not particularly limited and can be any of transition metals or typical metals. Specifically, examples of materials that can be used as the metal support layer 6 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 metals such as iron, Group 8 (Group 9) metals such as cobalt, Group 8 (Group 10) metals such as nickel and platinum, Group 1 (Group 11) metals such as copper, silver, and gold, Group 2 (Group 12) metals such as zinc, Group 3 (Group 13) metals such as aluminum and gallium, and Group 4 (Group 14) metals such as germanium and tin. These materials can be used alone or in combination.

[0043] The thickness of the metal support layer 6 is, for example, 10 μm or more, preferably 50 μm or more, and also, for example, 10 mm or less. The width W1 of the wiring metal portion 10 is, for example, 5 μm or more, preferably 10 μm or more, and also, for example, 500 μm or less, preferably 300 μm or less. Furthermore, the width W1 of the wiring metal portion 10 is the longest distance between the two end faces of the wiring metal portion 10 in the width direction.

[0044] like Figure 2 A~ Figure 2 As shown in Figure B, the substrate insulating layer 7 is disposed on one side of the metal support layer 6 in the thickness direction. The substrate insulating layer 7 has the same external shape as the wiring circuit board 1. Figure 1 A~ Figure 1 As shown in B, the substrate insulating layer 7 integrally has a wiring body base 13 corresponding to the wiring body 2, a first connection base 14 corresponding to the first connector 3, and a second connection base 15 corresponding to the second connector 4.

[0045] like Figure 1 A~ Figure 2As shown in Figure A, the wiring body base 13 has the same external shape as the wiring body 2. That is, multiple (two) wiring body bases 13 are provided corresponding to multiple wiring bodies 2. Each of the multiple wiring body bases 13 has, for example, a generally rectangular shape in cross-section. The width W2 of the wiring body base 13 is wider than the width W1 of the wiring body metal portion 10. When projected along the thickness direction, the two ends of the wiring body base 13 in the width direction protrude outwards than the two ends of the wiring body metal portion 10 in the width direction. That is, the surfaces on the other side of the thickness direction of the two ends of the wiring body base 13 in the width direction are exposed on the other side of the thickness direction. In other words, the two ends of the surface on the other side of the thickness direction of the wiring body base 13 in the width direction are exposed from the wiring body metal portion 10. On the other hand, the middle part of the surface on the other side of the thickness direction of the wiring body base 13 in the width direction is in contact with the entire surface on one side of the thickness direction of the wiring body metal portion 10.

[0046] like Figure 1 B and Figure 2 As shown in Figure B, the first connecting base 14 has the same external shape as the first connecting body 3. When viewed from below, the first connecting base 14 has, for example, a generally rectangular shape that is larger than the first connecting metal part 11.

[0047] The second connecting base 15 has the same external shape as the second connecting body 4. When viewed from below, the second connecting base 15 has, for example, a generally rectangular shape that is larger than the second connecting metal part 12.

[0048] Materials used as the base insulating layer 7 include, for example, insulating resins such as polyimide.

[0049] The thickness of the substrate insulating layer 7 is, for example, 1 μm or more, preferably 3 μm or more, and also, for example, 100 μm or less, preferably 50 μm or less. The width W2 of the wiring body base 13 is, for example, 15 μm or more, preferably 40 μm or more, and also, for example, 800 μm or less, preferably 500 μm or less. The ratio (W2 / W1) of the width W2 of the wiring body base 13 to the width W1 of the wiring body metal portion 10 is greater than 1, preferably 1.05 or more, more preferably 1.1 or more, even more preferably 1.25 or more, and also, for example, 5 or less, preferably 3 or less.

[0050] like Figure 2 A~ Figure 2 As shown in Figure B, the conductor layer 8 is disposed on one side of the substrate insulating layer 7 in the thickness direction. Figure 1 As shown in A, the conductor layer 8 integrally has a wiring 16, which is an example of a wiring layer corresponding to the wiring body 2, a first terminal 17 corresponding to the first connector 3, and a second terminal 18 corresponding to the second connector 4.

[0051] Wiring 16 is provided in each of the multiple wiring bodies 2. For example... Figure 2 As shown in Figure A, each of the plurality of wirings 16 is disposed in the middle portion (specifically, the central portion) of the width direction of the surface on one side of the thickness direction of the plurality of wiring body bases 13. Furthermore, the width W3 of the wiring 16 is narrower than the width W1 of the wiring body metal portion 10. And, when projected along the thickness direction, the wiring 16 is contained within the wiring body metal portion 10. The wiring 16 has a generally rectangular shape when viewed in cross-section.

[0052] like Figure 1 As shown in Figure A, the first terminal 17 is continuous with one end edge of the wiring 16 along its length. The first terminal 17 has, for example, a generally rectangular shape when viewed from above. The first terminal 17 is disposed on the thickness-direction side of the first connecting base 14. The first terminal 17 is provided correspondingly with a plurality of wirings 16.

[0053] The second terminal 18 is connected to the other end edge of the wiring 16 along its length. The second terminal 18 has, for example, a generally rectangular shape when viewed from above. The second terminal 18 is disposed on the thickness side of the second connection base 15. The second terminal 18 is provided correspondingly to a plurality of wirings 16.

[0054] Materials used as conductor layer 8 include, for example, copper, silver, gold, iron, aluminum, chromium, and their alloys. From the viewpoint of obtaining good electrical properties, copper is preferred.

[0055] The thickness of the conductor layer 8 is, for example, 1 μm or more, preferably 3 μm or more, and also, for example, 50 μm or less, preferably 30 μm or less. The width W3 of the wiring 16 is, for example, 1 μm or more, preferably 5 μm or more, and also, for example, 200 μm or less, preferably 100 μm or less. Furthermore, the ratio (W3 / W2) of the width W3 of the wiring 16 to the width W2 of the wiring body base 13 is less than 1, preferably 0.9 or less, preferably 0.8 or less, more preferably 0.7 or less, even more preferably 0.5 or less, and also, for example, 0.01 or more, preferably 0.1 or more. Furthermore, the ratio (W3 / W1) of the width W3 of the wiring 16 to the width W1 of the wiring body metal portion 10 is, for example, 0.1 or more, preferably 0.2 or more, and also, for example, 5 or less, preferably 2 or less.

[0056] like Figure 2 As shown in Figure A, the cover insulating layer 9 is disposed on one side of the base insulating layer 7 in the thickness direction in a manner that covers the conductor layer 8. The cover insulating layer 9 is included in the base insulating layer 7 when projected along the thickness direction. The cover insulating layer 9 has a wiring cover portion 19 corresponding to the wiring body 2.

[0057] Multiple (two) wiring cover portions 19 are provided corresponding to multiple wiring bodies 2. Each wiring cover portion 19, for example, has a roughly U-shaped form that opens towards the other side in the thickness direction when viewed in cross-section. The wiring cover portion 19 has a surface 20 on one side in the thickness direction, a surface 21 on the other side in the thickness direction opposite to the surface 20 on one side in the thickness direction, and two side surfaces 22 connecting the two end edges in the width direction of the surface 20 on one side in the thickness direction and the surface 21 on the other side in the thickness direction. The surface 20 on one side in the thickness direction has a flat surface parallel to the surface on one side in the thickness direction of the wiring body base 13. The surface 21 on the other side in the thickness direction contacts the surface on one side in the thickness direction and the two side surfaces in the width direction of the wiring 16, as well as the surface on one side in the thickness direction of the portion of the wiring body base 13 located around the wiring 16. The two side surfaces 22 are sloped surfaces that decrease in relative distance as they move towards one side in the thickness direction.

[0058] As a material for covering the insulating layer 9, insulating resins such as polyimide can be cited as examples.

[0059] The thickness of the insulating layer 9 is the interval between the surface 20 on the thickness direction side of the wiring cover portion 19 and the surface on the thickness direction side of the wiring 16. Specifically, it is, for example, 1 μm or more, preferably 5 μm or more, and also, for example, 100 μm or less, preferably 50 μm or less. The width W4 of the wiring cover portion 19 is the longest distance in cross-section between the two side surfaces 22, which is narrower than the width W2 of the wiring base 13 and wider than the width W3 of the wiring 16. The width W4 of the wiring cover portion 19 is, for example, 10 μm or more, preferably 30 μm or more, and also, for example, 500 μm or less, preferably 300 μm or less. The ratio (W4 / W2) of the width W4 of the wiring cover portion 19 to the width W2 of the wiring base 13 is less than 1, preferably 0.95 or less, more preferably 0.9 or less, even more preferably 0.8 or less, and also, for example, 0.5 or more.

[0060] Next, refer to Figure 3 A~ Figure 3 E will be used to describe a method for manufacturing the wiring circuit board 1. This method includes a first step of forming a substrate insulating layer 7 on one side of the metal sheet 25 in the thickness direction, a second step of forming a conductor layer 8 on one side of the substrate insulating layer 7 in the thickness direction, a third step of covering the wiring 16 with a cover insulating layer 9, and a fourth step of etching the metal sheet 25 to form a metal support layer 6. In this manufacturing method, steps 1 through 4 are performed sequentially. Furthermore, this manufacturing method is, for example, implemented using a roll-to-roll method.

[0061] like Figure 3 As shown in A, in the first step, metal sheet 25 is prepared.

[0062] Metal sheet 25 is a metal substrate used to form metal support layer 6, and has a larger external shape than metal support layer 6. The material and thickness of metal sheet 25 are the same as those of metal support layer 6.

[0063] Next, a varnish containing a photosensitive insulating resin is applied to the entire surface of the metal sheet 25 on one side in the thickness direction. Then, a wiring substrate 13 and a first connection substrate 14 (see reference) are formed by photolithography. Figure 2 B) and the second connecting base 15 (see reference) Figure 1 A~ Figure 1 B) The base insulating layer 7.

[0064] like Figure 3 As shown in B, in the second process, for example by additive or subtractive methods, a surface with wiring 16 and a first terminal 17 (see reference) is formed on one side of the substrate insulating layer 7 in the thickness direction. Figure 2 B) and the second terminal 18 (refer to) Figure 1 A~ Figure 1 B) Conductor layer 8. The width W3 of wiring 16 is narrower than the width W2 of wiring base 13.

[0065] like Figure 3 As shown in step C, in the third step, a varnish containing a photosensitive insulating resin is applied to the entire surface of the metal sheet 25, the substrate insulating layer 7, and the conductor layer 8 along one side in the thickness direction. Then, a cover insulating layer 9 having a wiring cover portion 19 is formed by photolithography. The wiring cover portion 19 covers the wiring 16. The width W4 of the wiring cover portion 19 is narrower than the width W2 of the wiring base 13.

[0066] like Figure 3 As shown in E, in the fourth process, the metal sheet 25 is etched from both sides in the thickness direction to form a metal support layer 6 such that the width W1 of the wiring metal part 10 of the wiring body 2 is narrower than the width W2 of the wiring body base 13.

[0067] like Figure 3 D~ Figure 3 As shown in E, the fourth step includes a fifth step of disposing the first photoresist 23 on one side of the metal sheet 25 in the thickness direction, a sixth step of disposing the second photoresist 24 on the other side of the metal sheet 25 in the thickness direction, and a seventh step of etching the metal sheet 25. The fifth and sixth steps are performed simultaneously. Alternatively, the fifth and sixth steps are performed sequentially. Furthermore, the sixth and fifth steps may also be performed sequentially.

[0068] In the fifth step, the first resist 23 is disposed on one side of the metal sheet 25 in the thickness direction, such that it covers the base 13 of the wiring body, the wiring 16, and the wiring body cover 19. That is, the first resist 23 covers the wiring body unit 26, which is composed of one base 13 of the wiring body, one wiring 16, and one wiring body cover 19.

[0069] The first resist 23 does not cover multiple (two) wiring units 26 adjacent to each other in the width direction. The first resist 23 exposes the central portion 27 located between multiple (two) wiring units 26 on the side of the metal sheet 25 in the thickness direction.

[0070] The first resist 23 covers the two end faces (two sides) of the base 13 of multiple (two) wiring bodies in the width direction.

[0071] The width-direction length L of the end-face covering portion 28 in the first resist 23, which covers both ends of the wiring substrate 13 in the width direction, can be appropriately set according to the amount of lateral etching in the subsequent seventh process and the width W1 of the wiring metal portion 10 formed by the seventh process. The width-direction length L of the end-face covering portion 28 covering the ends of the wiring substrate 13 is, for example, 1 μm or more, preferably 3 μm or more, and also, for example, 50 μm or less, preferably 25 μm or less.

[0072] Furthermore, the first resist 23 exposes the side 31 of the wiring unit 26 located on the widest side, which is further away from the width direction, on the thickness direction side of the metal sheet 25. Additionally, the first resist 23 exposes the side 32 of the wiring unit 26 located on the other side, which is further away from the width direction, on the thickness direction side of the metal sheet 25.

[0073] In the fifth step, firstly, a dry film resist is applied to the entire surface of the metal sheet 25, the substrate insulating layer 7, and the cover insulating layer 9 on one side in the thickness direction. Then, the first resist 23 with the above shape is formed by photolithography.

[0074] In step 6, the second photoresist 24 is disposed on the surface of the metal sheet 25 on the other side of its thickness direction, overlapping the first photoresist 23 when projected along the thickness direction. When projected along the thickness direction, the second photoresist 24 has the same pattern as the first photoresist 23. Specifically, the dry film photoresist is disposed on the entire surface of the metal sheet 25 on the other side of its thickness direction, and then the second photoresist 24 with the above-described shape is formed by photolithography.

[0075] By performing steps 5 and 6, a resist laminate 30 comprising a second resist 24, a metal sheet 25, a substrate insulating layer 7, a conductor layer 8, a cover insulating layer 9, and a first resist 23 can be obtained. In the resist laminate 30, the metal sheet 25 includes an overlapping portion (inner metal portion) 29 that overlaps with the end face covering portion (both ends in the width direction) 28 of the first resist 23 and the two ends in the width direction of the second resist 24.

[0076] In the seventh step, the metal sheet 25 is etched from one side and the other side of the thickness direction. For example, the shape of the metal sheet 25 is shaped by wet etching using an etching solution. Specifically, the etching solution is brought into contact with the surface of the resist laminate 30 on one side and the surface on the other side of the thickness direction.

[0077] Therefore, by contacting the etching solution with one side of the metal sheet 25 in the thickness direction and the other side in the thickness direction, the central portion 27, the portion 31 on one side away from the metal sheet 25 and the portion 32 on the other side away from the metal sheet 25 are removed first.

[0078] Next, the overlapping portion 29 (the inner metal portion) is removed. That is, the overlapping portion 29 is etched laterally.

[0079] Further lateral etching is performed, and the two end portions 33 on the other side of the thickness direction of the two ends of the wiring base 13 in the width direction of the metal sheet 25 are removed. That is, the two end portions 33 are also laterally etched. In other words, in this seventh process, after the central portion 27, the portion 31 on one side and the portion 32 on the other side of the metal sheet 25 are etched away, the overlapping portion 29 and the two end portions 33 of the metal sheet 25 are laterally etched in sequence.

[0080] Through this seventh process, the metal sheet 25 is formed into a metal support layer 6. In addition, in a cross section orthogonal to the direction in which the wiring 16 extends, the metal sheet 25 corresponding to the wiring body unit 26 is divided into a plurality of (two) wiring body metal portions 10 that are spaced apart from each other in the width direction.

[0081] Thus, a wiring circuit board 1 having a metal support layer 6, a base insulating layer 7, a conductor layer 8, and a covering insulating layer 9 is manufactured.

[0082] (Effects of one implementation method)

[0083] Furthermore, in this manufacturing method, such as Figure 3 As shown in Figure C, in the third process, the insulating layer 9 is formed such that the width W4 of the wiring cover 19 is narrower than the width W2 of the wiring base 13. Additionally, as... Figure 3 As shown in E, in the fourth step, a metal support layer 6 is formed such that the width W1 of the wiring body metal portion 10 is narrower than the width W2 of the wiring body base 13.

[0084] Therefore, as Figure 3 As shown in D, even if a first resist 23 corresponding to the shape of the wiring metal portion 10 is formed on one side of the metal sheet 25 in the thickness direction, the first resist 23 can cover the width end of the wiring cover portion 19, which is narrower than the width of the wiring base 13. Therefore, shape defects of the wiring metal portion 10 caused by the width end of the wiring cover portion 19 protruding outwards compared to the width end of the first resist 23 can be suppressed (described in the following comparative examples). Therefore, a metal support layer 6 having a wiring metal portion 10 with a desired shape can be formed.

[0085] On the other hand, in the comparative example, in Figure 4 In the third process shown in A, the covering insulation layer 9 is formed such that the width W4 of the wiring body covering portion 19 is wider than the width W2 of the wiring body base 13. Thus, in Figure 4 In step 5 shown in B, even if a first resist 23 corresponding to the shape of the wiring metal portion 10 is formed on one side of the metal sheet 25 in the thickness direction, the first resist 23 cannot cover the two sides 22 (the other end 34 in the thickness direction) of the wiring cover portion 19, which is wider than the width of the wiring base 13, leaving the two sides 22 exposed. As a result, the two sides 22 (the other end 34 in the thickness direction) of the wiring cover portion 19 will function as an anti-corrosion coating, causing shape defects (inaccuracy) in the wiring metal portion 10. In other words, a wiring metal portion 10 wider than desired will be formed. Therefore, a metal support layer 6 with a desired shape for the wiring metal portion 10 cannot be formed.

[0086] like Figure 3 A and Figure 3 As shown in C, in the fourth step of the manufacturing method of one embodiment, since a wiring body base 13, a wiring 16 and a wiring body cover 19 corresponding to each of the multiple wiring body metal parts 10 are formed, the external shape of each of the multiple wiring body metal parts 10 can be designed in accordance with the wiring body base 13, the wiring 16 and the wiring body cover 19.

[0087] Furthermore, in this manufacturing method, since the metal sheet 25 is etched by side etching of the overlapping portion 29 (and further, the two end portions 33) of the metal sheet 25, it is possible to reliably form a wiring metal portion 10 with a width narrower than the width of the wiring base 13.

[0088] In addition, such as Figure 2As shown in Figure A, in this wiring circuit board 1, the width W1 of the wiring body metal portion 10 and the width W4 of the wiring body cover portion 19 are narrower than the width W2 of the wiring body base 13. That is, in the wiring body 2, which is their stacked portion, the width W2 of the wiring body base 13 is the largest. Therefore, the wiring body 2 can be made to have a shape with a narrower width corresponding to the width W2 of the wiring body base 13.

[0089] (Modified Example)

[0090] In the following variations, the same reference numerals are used for components and processes identical to those in the first embodiment, and detailed descriptions are omitted. Furthermore, in each variation, unless otherwise specified, the same effects as in the first embodiment can be achieved. Moreover, the first embodiment and its variations can be appropriately combined.

[0091] like Figure 5 As shown, the wiring circuit board 1 does not have an opening 5 (see reference). Figure 2 A). Multiple (two) wirings 16 are provided corresponding to one wiring body metal part 10. That is, the wiring circuit board 1 has one wiring body 2, and the one wiring body 2 has multiple (two) wirings 16.

[0092] Compared to Figure 5 Of the variations, one embodiment is preferred. If it is an embodiment, then as follows... Figure 2 A and Figure 3 As shown in E, in the fourth step, one wire 16 is formed corresponding to each of the multiple wire metal portions 10. Therefore, the external shape of each of the multiple wire metal portions 10 can be designed to match the corresponding wire 16.

[0093] Furthermore, the above-described invention is provided as an illustrative embodiment of the present invention, but it is merely illustrative and not intended to be limiting. Modifications of the invention that will be apparent to those skilled in the art are included in the foregoing claims.

[0094] Industrial availability

[0095] Wiring circuit boards can be used for a variety of applications.

[0096] Explanation of reference numerals in the attached figures

[0097] 1. Wiring circuit board; 6. Metal support layer; 7. Base insulating layer; 9. Cover insulating layer; 16. Wiring; 20. Surface on one side of the thickness direction (wiring body cover); 21. Surface on the other side of the thickness direction (wiring body cover); 23. First resist; 24. Second resist; 25. Metal sheet; 29. ​​Overlapping portion; W1. Width (width of the metal part of the wiring body); W2. Width (width of the base part of the wiring body); W3. Width (width of the wiring); W4. Width (width of the wiring body cover).

Claims

1. A method for manufacturing a wiring circuit board, characterized in that, The method for manufacturing this wiring circuit board includes: In the first step, a base insulating layer is formed on one side of the metal sheet in the thickness direction. In the second step, a wiring layer is formed on one side of the base insulating layer in the thickness direction, such that the width of the wiring layer in the direction orthogonal to the extension direction and the thickness direction of the wiring layer is narrower than the width of the base insulating layer. In the third step, a covering insulating layer is formed on the side of the base insulating layer on the thickness direction side of the portion exposed from the wiring layer, such that the covering insulating layer covers the wiring layer and the width of the covering insulating layer is narrower than the width of the base insulating layer. as well as In the fourth step, the metal sheet is etched from both sides in the thickness direction to form the metal support layer such that its width is narrower than the width of the substrate insulating layer. In the fourth step, the metal sheet is divided into multiple spaced-apart metal bodies in a cross-section orthogonal to the extending direction. In the first step, a substrate insulating layer corresponding to each of the plurality of metal bodies is formed. In the second step, at least one wiring layer corresponding to each of the plurality of metal bodies is formed. In the third step, a covering insulating layer corresponding to each of the plurality of metal bodies is formed. The fourth step includes: In the fifth step, the first resist is disposed on the side of the metal sheet in the thickness direction such that it covers the base insulating layer and the cover insulating layer corresponding to the metal body. In the sixth step, the second photoresist is disposed on the surface of the metal sheet on the other side of the thickness direction, such that it overlaps with the first photoresist when projected along the thickness direction. In the fifth step, the first photoresist is used to cover the thickness side and the width side end face of the width direction end of the plurality of substrate insulating layers.

2. The method for manufacturing a wiring circuit board according to claim 1, characterized in that, The fourth step includes a seventh step in which the metal sheet is etched by means of side etching the overlapping portion of the metal sheet that overlaps with the two ends of the first and second resists in the width direction.

3. A wiring circuit board, characterized in that, The wiring circuit board has the following features: Multiple wiring elements extending along a direction are divided in a width direction orthogonal to both the direction and the thickness direction; and A connector that connects one end of the plurality of wiring bodies in the width direction. The wiring circuit board includes: Metal support layer; A base insulating layer disposed on one side of the metal support layer in the thickness direction; A conductor layer disposed on one side of the substrate insulating layer in the thickness direction; as well as A covering insulating layer is disposed on one side of the base insulating layer in the thickness direction, such that it covers a portion of the conductor layer. The metal support layer has a wiring body metal portion corresponding to the wiring body and a connecting metal portion corresponding to the connecting body. The substrate insulating layer has a wiring body base corresponding to the wiring body and a connection base corresponding to the connector. The covering insulation layer has a wiring body covering portion corresponding to the wiring body. The width (W4) of the wiring body cover is narrower than the width (W2) of the wiring body base. The width (W1) of the metal portion of the wiring body is narrower than the width (W2) of the base portion of the wiring body.

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