Patent Publication Number: US-11026334-B2

Title: Wired circuit board and producing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a Divisional of U.S. patent application Ser. No. 15/478,711, filed on Apr. 4, 2017, which claims priority from Japanese Patent Application No. 2016-077551, filed on Apr. 7, 2016, the contents of which are hereby incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a wired circuit board and a production method thereof, in particular, to a method for producing a wired circuit board, and a wired circuit board produced by the method. 
     Description of Related Art 
     It has been known that a wired circuit board is produced by providing an insulating layer and a wiring pattern thereon. 
     For example, Japanese Unexamined Patent Publication No. 2014-127216 has proposed a method for producing a suspension board with circuit: the method includes a step of forming a first portion having a first thickness and a second portion having a second thickness that is smaller than the first thickness in the insulating layer, and a step of forming a wiring pattern so as to extend on the first portion and the second portion of the insulating layer. 
     To be specific, in the production method described in Patent Document 1, in the step of forming the wiring pattern, the wiring pattern is formed on the top face of the insulating layer so that the boundary between the top face and the boundary face of the first portion extends in a first direction, the side of the wiring pattern extends in a second direction crossing the first direction, and the second direction forms an angle of 60 degrees or more and 90 degrees or less relative to the first direction. 
     Because the boundary face is formed between the top face of the first portion and the top face of the second portion, in the step of forming the wiring pattern on the insulating layer by photo lithography technology, reflection of exposure light is caused at the boundary face, and the reflected light applies indirectly to other regions. However, in the method described in Patent Document 1, the exposure light is reflected in a direction that is close to the direction in which the wiring pattern extends at the boundary face, and therefore, the reflected light substantially does not affect the pattern of the original exposure light. Thus, breakage or short circuit is prevented in the wiring pattern formed by the photo lithography technology. 
     SUMMARY OF THE INVENTION 
     Recently, when producing a small-sized wired circuit board, sometimes a wiring pattern is disposed with a complicated pattern. In such a case, the wiring pattern may not be formed so as to form an angle between the second direction and the first direction to be 60 degrees or more and 90 degrees or less as in Japanese Unexamined Patent Publication No. 2014-127216. Then, there are disadvantages in that inadequate formation of the wiring pattern cannot be prevented. 
     The present invention provides a method for producing a wired circuit board with which deformation of the conductive pattern can be suppressed, while the conductive pattern is provided with a high degree of freedom, and a wired circuit board produced by the method. 
     The present invention (1) includes a method for producing a wired circuit board including an insulating layer and a conductive pattern, the method including the steps of: 
     a step (1), in which the insulating layer having an inclination face is provided; 
     a step (2), in which a metal thin film is provided at least on the surface of the insulating layer; 
     a step (3), in which a photoresist is provided on the surface of the metal thin film; 
     a step (4), in which a photomask is disposed so that a first portion, where the conductive pattern is to be provided in the photoresist, is shielded from light, and the photoresist is exposed to light through the photomask; 
     a step (5), in which the first portion is removed to expose the metal thin film corresponding to the first portion; and 
     a step (6), in which the conductive pattern is provided on the surface of the metal thin film exposed from the photoresist, 
     wherein the inclination face has a second portion that allows the reflected light reflected at the metal thin film to reach the first portion, and 
     in the step (4), the photomask is disposed so that the photoresist facing the second portion is shielded from light. 
     With the method, in the step (4), the photomask is disposed so that the photoresist facing the second portion is shielded from light. Therefore, even when the inclination face has the second portion that allows the reflected light reflected at the metal thin film to reach the first portion, the above-described reflected light can be prevented from reaching the first portion. Thus, in the step (4), the first portion is surely shielded from light and the photoresist can be exposed to light; in the step (5), the metal thin film corresponding to the first portion is surely exposed; and subsequently, in the step (6), the conductive pattern in which deformation is suppressed can be surely provided. 
     Therefore, a conductive pattern having high reliability can be provided with a high degree of freedom. 
     As a result, a wired circuit board having a high degree of freedom with excellent connection reliability can be produced. 
     The present invention (2) includes a method for producing a wired circuit board including an insulating layer and a conductive pattern, the method including the steps of: 
     a step (1), in which the insulating layer having an inclination face is provided; 
     a step (2), in which a conductive layer is provided at least on the surface of the insulating layer; 
     a step (3), in which a photoresist is provided on the surface of the conductive layer; 
     a step (4), in which a photomask is disposed so that a first portion, where the conductive pattern is to be provided in the photoresist, is shielded from light, and the photoresist is exposed to light through the photomask; 
     a step (5), in which the photoresist other than the first portion is removed so as to leave the first portion; and 
     a step (6), in which the conductive layer exposed from the first portion is removed to form the conductive pattern; 
     wherein the inclination face has a second portion that allows the reflected light reflected at the conductive layer to reach the first portion, and 
     in the step (4), the photomask is disposed so that the photoresist facing the second portion is shielded from light. 
     With the method, in the step (4), the photomask is disposed so that the photoresist facing the second portion is shielded from light. Therefore, even when the inclination face has the second portion that allows the reflected light reflected at the conductive layer to reach the first portion, the above-described reflected light can be prevented from reaching the first portion. Thus, in the step (4), the first portion is surely shielded from light and the photoresist can be exposed to light; in the step (5), the photoresist other than the first portion is surely removed so as to leave the first portion; and subsequently, in the step (6), the conductive pattern in which deformation is suppressed can be surely provided. 
     Therefore, a conductive pattern having high reliability can be provided with a high degree of freedom. 
     As a result, a wired circuit board having a high degree of freedom with excellent connection reliability can be produced. 
     The present invention (3) includes the method for producing a wired circuit board described in the above-described (1) or (2), wherein the second portion has a bent portion bending in one direction when viewed from the top, and the bent portion is made so that the reflected light corresponding to the bent portion is focused on the first portion. 
     When the second portion has the bent portion bending in one direction when viewed from the top, and the bent portion is made so that the reflected light corresponding to the bent portion is focused on the first portion, in the step (4), the reflected light corresponding to the bent portion is focused on the first portion, so that the first portion cannot be shielded from light; in the step (5), the metal thin film corresponding to the first portion cannot be exposed; and in the step (6), the conductive pattern having deformation is provided. 
     However, with the method, in the step (4), the photomask is disposed so that the photoresist facing the second portion is shielded from light, and thus, in the step (4), the reflected light is prevented from being focused on the first portion and the first portion can be surely shielded from light; in the step (5), the metal thin film corresponding to the first portion is surely exposed; and subsequently, in the step (6), the conductive pattern in which deformation is suppressed can be surely provided. 
     The present invention (4) includes the method for producing a wired circuit board described in any one of the above-described (1) to (3), wherein the conductive pattern has a wire having a width W of 15 μm or less, the first portion corresponding to the wire is disposed at an interval L of 20 μm or less relative to the second portion when viewed from the top, and the width W (μm) and the interval L (μm) satisfy the following formula (1):
 
 L≤− 2× W+ 35  (1)
 
     When the conductive pattern has the wire having the narrow width W of 15 μm or less, the second portion is disposed at the predetermined interval L relative to the wire when viewed from the top, and the above-described formula (1) is satisfied, in the step (4), the reflected light corresponding to the second portion easily reaches the first portion. Thus, the first portion cannot be shielded from light; in the step (5), the metal thin film corresponding to the first portion cannot be exposed; and in the step (6), the conductive pattern having deformation is provided. 
     However, with the method, in the step (4), the photomask is disposed so that the photoresist facing the second portion is shielded from light, and thus, in the step (4), the first portion is surely shielded from light and the photoresist can be exposed to light; in the step (5), the metal thin film corresponding to the first portion is surely exposed; and subsequently, in the step (6), the wire in which deformation is suppressed can be surely provided. 
     The present invention (5) includes the method for producing a wired circuit board described in any one of the above-described (1) to (4), wherein the conductive pattern has a wire and a dummy wire provided independently from the wire, and in the step (4), a third portion, where the dummy wire is to be provided in the photoresist, is overlapped with the second portion when viewed from the top. 
     With the method, in the step (4), the third portion, where the dummy wire is to be provided in the photoresist, is overlapped with the second portion when viewed from the top, so that in the step (4), the third portion can be surely shielded from light. Therefore, the occurrence of the reflected light in the second portion that is overlapped with the third portion can be prevented. Thus, the exposure to light of the first portion caused by the reflected light in the second portion is surely prevented, and the wire can be surely provided. 
     The present invention (6) includes the method for producing a wired circuit board described in any one of the above-described (1) to (5), wherein the conductive pattern has a wire and a dummy portion provided continuously from the wire, and in the step (4), a third portion, where the dummy portion is to be provided in the photoresist, is overlapped with the second portion when viewed from the top. 
     With the method, in the step (4), the third portion, where the dummy portion is to be provided in the photoresist, is overlapped with the second portion when viewed from the top, so that in the step (4), the third portion can be surely shielded from light. Therefore, the occurrence of the reflected light in the second portion that is overlapped with the third portion can be prevented. As a result, the exposure to light of the first portion caused by the reflected light in the second portion is surely prevented, and the wire can be surely provided. 
     The present invention (7) includes a wired circuit board including an insulating layer having an inclination face and a conductive pattern having a wire and a dummy wire provided independently from the wire, 
     wherein the inclination face has a bent portion bending in one direction when viewed from the top, and 
     the dummy wire is overlapped with the bent portion when viewed from the top. 
     In the wired circuit board, when the inclination face has the bent portion bending in one direction when viewed from the top, in photo processing of the production step of the wired circuit board, a light shielding failure occurs in the portion corresponding to the wire caused by the unintended reflection corresponding to the bent portion, and as a result, the reliability of the wire is decreased. 
     However, in the wired circuit board, the conductive pattern has the dummy wire and the dummy wire is overlapped with the bent portion when viewed from the top, so that in photo processing of the production step of the wired circuit board, by preventing the unintended reflection corresponding to the bent portion, the occurrence of the light shielding failure in the portion corresponding to the wire can be prevented. Therefore, the reliability of the wire is improved. 
     The present invention (8) includes a wired circuit board including an insulating layer having an inclination face and a conductive pattern having a wire and a dummy portion provided continuously from the wire, 
     wherein the inclination face has a bent portion bending in one direction when viewed from the top, and 
     the dummy portion is overlapped with the bent portion when viewed from the top. 
     In the wired circuit board, when the inclination face has the bent portion bending in one direction when viewed from the top, in photo processing of the production step of the wired circuit board, a light shielding failure occurs in the portion corresponding to the wire caused by the unintended reflection corresponding to the bent portion, and as a result, the reliability of the wire is decreased. 
     However, in the wired circuit board, the conductive pattern has the dummy portion and the dummy portion is overlapped with the bent portion when viewed from the top, so that in photo processing of the production step of the wired circuit board, by preventing the unintended reflection corresponding to the bent portion, the occurrence of the light shielding failure in the portion corresponding to the wire can be prevented. Therefore, the reliability of the wire is improved. 
     The present invention (9) includes a wired circuit board including an insulating layer having an inclination face and a conductive pattern having a wire having a width W of 15 μm or less and a dummy wire provided independently from the wire, wherein the inclination face has a second portion disposed at an interval L of 20 μm or less relative to the wire when viewed from the top, the width W (μm) and the interval L (μm) satisfy the following formula (1), and the dummy wire is overlapped with the wire when viewed from the top:
 
 L≤− 2× W+ 35  (1)
 
     When in the wired circuit board, the wire having the narrow width of 15 μm or less is included, the inclination face has the second portion disposed at the predetermined interval relative to the wire when viewed from the top, and the above-described formula (1) is satisfied, in photo processing of the production step of the wired circuit board, a light shielding failure easily occurs in the portion corresponding to the wire caused by the unintended reflection corresponding to the inclination face, and the reliability of the wire is decreased. 
     However, in the wired circuit board, the conductive pattern has the dummy wire and the dummy wire is overlapped with the wire when viewed from the top, so that in photo processing of the production step of the wired circuit board, by preventing the unintended reflection corresponding to the bent portion, the occurrence of the light shielding failure in the portion corresponding to the wire can be prevented. Therefore, the reliability of the wire is improved. 
     The present invention (10) includes a wired circuit board including an insulating layer having an inclination face and a conductive pattern having a wire having a width W of 15 μm or less and a dummy portion provided continuously from the wire, wherein the conductive pattern has a second portion disposed at an interval L of 20 μm or less relative to the wire when viewed from the top, the width W (μm) and the interval L (μm) satisfy the following formula (1), and the dummy portion is overlapped with the wire when viewed from the top:
 
 L≤− 2× W+ 35  (1)
 
     When in the wired circuit board, the wire having the narrow width of 15 μm or less is included, the inclination face has the second portion disposed at the predetermined interval relative to the wire when viewed from the top, and the above-described formula (1) is satisfied, in photo processing of the production step of the wired circuit board, a light shielding failure easily occurs in the portion corresponding to the wire caused by the unintended reflection corresponding to the inclination face, and the reliability of the wire is decreased. 
     However, in the wired circuit board, the conductive pattern has the dummy portion and the dummy portion is overlapped with the wire when viewed from the top, so that in photo processing of the production step of the wired circuit board, by preventing the unintended reflection corresponding to the bent portion, the occurrence of the light shielding failure in the portion corresponding to the wire can be prevented. Therefore, the reliability of the wire is improved. 
     With the method for producing a wired circuit board of the present invention, a wired circuit board having a high degree of freedom with excellent connection reliability can be produced. 
     In the wired circuit board of the present invention, the reliability of the wire is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a plan view of the wired circuit board of the present invention in a first embodiment. 
         FIG. 2  shows a cross-sectional view along line a-a of the wired circuit board shown in  FIG. 1 . 
         FIG. 3A  to  FIG. 3C  show a first embodiment of the method for producing a wired circuit board of the present invention, illustrating process diagrams of the method for producing a wired circuit board shown in  FIG. 2 : 
         FIG. 3A  illustrating a step (i), in which an insulating base layer is prepared, 
         FIG. 3B  illustrating a step (ii), in which a first conductive pattern is provided, and 
         FIG. 3C  illustrating a step (1), in which an intermediate insulating layer is provided. 
         FIG. 4D  to  FIG. 4F  show, following  FIG. 3C , the first embodiment of the method for producing a wired circuit board of the present invention, illustrating process diagrams of the first embodiment of the method for producing a wired circuit board: 
         FIG. 4D  illustrating a step (2), in which a metal thin film is provided, 
         FIG. 4E  illustrating a step (3), in which a photoresist is provided, and 
         FIG. 4F  illustrating a step (4), in which the photoresist is exposed to light. 
         FIG. 5G  to  FIG. 5I  show, following  FIG. 4F , the first embodiment of the method for producing a wired circuit board of the present invention, illustrating process diagrams of the first embodiment of the method for producing a wired circuit board: 
         FIG. 5G  illustrating a step (4), in which a first portion and a third portion of the photoresist are removed, 
         FIG. 5H  illustrating a step (5), in which a second conductive pattern is provided, and 
         FIG. 5I  illustrating a step (iii), in which the photoresist is removed. 
         FIG. 6J  and  FIG. 6K  show, following  FIG. 5I , the first embodiment of the method for producing a wired circuit board of the present invention, illustrating process diagrams of the first embodiment of the method for producing a wired circuit board: 
         FIG. 6J  illustrating a step (iv), in which the metal thin film corresponding to the photoresist is removed, and 
         FIG. 6K  illustrating a step (v), in which an insulating cover layer is provided. 
         FIG. 7  shows a plan view of a wired circuit board of prior art (Comparative Example). 
         FIG. 8A  to  FIG. 8C  are process diagrams illustrating the method for producing a wired circuit board shown in  FIG. 7  and cross-sectional views along line b-b: 
         FIG. 8A  illustrating a step (4), in which a photoresist is exposed to light, 
         FIG. 8B  illustrating a step (5), in which a first portion of the photoresist is removed, and 
         FIG. 8C  illustrating a step (6), in which a second conductive pattern is provided. 
         FIG. 9A  to  FIG. 9C  are process diagrams illustrating a second embodiment of the method for producing a wired circuit board of the present invention: 
         FIG. 9A  illustrating a step (2), in which a conductive layer is provided, 
         FIG. 9B  illustrating a step (3), in which a photoresist is provided, a photomask is disposed, and the photoresist is exposed to light, and 
         FIG. 9C  illustrating a step (4), in which a first portion and a third portion in the photoresist are removed. 
         FIG. 10D  to  FIG. 10F  show, following  FIG. 9C , process diagrams illustrating the second embodiment of the method for producing a wired circuit board of the present invention: 
         FIG. 10D  illustrating a step (5), in which the conductive layer exposed from the photoresist is removed to form a second conductive pattern, 
         FIG. 10E  illustrating a step of removing the photoresist, and 
         FIG. 10F  illustrating a step (v), in which an insulating cover layer is provided. 
         FIG. 11  shows a plan view of the wired circuit board in a third embodiment of the present invention. 
         FIG. 12  shows a cross-sectional view along line c-c of the wired circuit board shown in  FIG. 11 . 
         FIG. 13A  to  FIG. 13C  show the third embodiment of the method for producing a wired circuit board of the present invention, illustrating process diagrams of the method for producing a wired circuit board shown in  FIG. 12 : 
         FIG. 13A  illustrating a step (4), in which a photoresist is exposed to light, 
         FIG. 13B  illustrating a step (4), in which a first portion and a third portion of the photoresist are collectively removed, and 
         FIG. 13C  illustrating a step (5), in which a second conductive pattern is provided. 
         FIG. 14D  to  FIG. 14F  show, following  FIG. 13C , the third embodiment of the method for producing a wired circuit board of the present invention, illustrating process diagrams of the method for producing a wired circuit board shown in  FIG. 12 : 
         FIG. 14D  illustrating a step of removing the photoresist, 
         FIG. 14E  illustrating a step (iv), in which a metal thin film corresponding to the photoresist is removed, and 
         FIG. 14F  illustrating a step (v), in which an insulating cover layer is provided. 
         FIG. 15  shows a plan view of the wired circuit board in a fourth embodiment of the present invention. 
         FIG. 16A  to  FIG. 16C  are process diagrams illustrating production of the wired circuit board shown in  FIG. 15  and show cross-sectional views along line d-d of the wired circuit board shown in  FIG. 15 : 
         FIG. 16A  illustrating a step (4), in which a photoresist is exposed to light, 
         FIG. 16B  illustrating a step (4), in which a first portion and a third portion in the photoresist are removed, and 
         FIG. 16C  illustrating a step (5), in which the photoresist and a metal thin film corresponding to the photoresist are removed. 
         FIG. 17A  to  FIG. 17C  are process diagrams illustrating production of the wired circuit board shown in  FIG. 15  and show cross-sectional views along line e-e of the wired circuit board shown in  FIG. 1 : 
         FIG. 17A  illustrating a step (4), in which the photoresist is exposed to light, 
         FIG. 17B  illustrating a step (4), in which the first portion of the photoresist is removed, and 
         FIG. 17C  illustrating a step (5), in which the photoresist and the metal thin film corresponding to the photoresist are removed. 
         FIG. 18  shows a plan view of a modified example (embodiment in which a second wire has a fourth linear portion) of the fourth embodiment. 
         FIG. 19  shows a plan view of a modified example (embodiment in which a first wire consists of only a third linear portion and the second wire consists of only the fourth linear portion) of the fourth embodiment. 
         FIG. 20  shows a plan view of the wired circuit board in a fifth embodiment of the present invention. 
         FIG. 21  shows a cross-sectional view along line f-f of the wired circuit board shown in  FIG. 20 . 
         FIG. 22  shows a plan view of a modified example (embodiment in which a second wire has a fourth linear portion) of the fifth embodiment. 
         FIG. 23  shows a plan view of a modified example (embodiment in which a first wire consists of only a third linear portion and the second wire consists of only the fourth linear portion) of the fifth embodiment. 
         FIG. 24  shows a cross-sectional view of a modified example (embodiment in which the first conductive pattern and the intermediate insulating layer are not provided) of the first embodiment. 
         FIG. 25  is a graph showing the relationship between L2 and W2 in Comparative Example 2 to Comparative Example 16. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1 , up-down direction in the plane of the paper is front-back direction (first direction), lower side is front side (one side in the first direction), and upper side in the plane of the paper is back side (the other side in the first direction). 
     In  FIG. 1 , left-right direction in the plane of the paper is width direction (second direction perpendicular to the first direction), left side in the plane of the paper is one side in the width direction (one side in the second direction), and right side in the plane of the paper is the other side in the width direction (the other side in the second direction). 
     In  FIG. 1 , paper thickness direction in the plane of the paper is up-down direction (third direction perpendicular to the first direction and the second direction, thickness direction), near side in the plane of the paper is upper side (one side in the third direction, one side in the thickness direction), and further side in the plane of the paper is lower side (the other side in the third direction, the other side in the thickness direction). The directions are, to be specific, in accordance with the direction arrows in the figures. 
     In  FIG. 1 ,  FIG. 7 ,  FIG. 11 ,  FIG. 15 ,  FIG. 18  to  FIG. 20 ,  FIG. 22 , and  FIG. 23 , to clearly show the relative positions of a first conductive pattern  4  and a second conductive pattern  6  described later, an insulating base layer  3 , an intermediate insulating layer  5 , and an insulating cover layer  7  described later are omitted. However, only a bent portion  17  (inclination face  15  at one side in the width direction) of the intermediate insulating layer  5  is shown in dotted hatching. 
     First Embodiment 
     The wired circuit board of the present invention has a single layer or a plurality of layers of the conductive pattern, and its layer structure is not particularly limited. The wired circuit board includes a suspension board with circuit including a metal supporting board, and a flexible wired circuit board including no metal supporting board. 
     In the following, a first embodiment of the wired circuit board and its production method of the present invention are described sequentially. 
     1. Wired Circuit Board 
     As shown in  FIGS. 1 and 2 , a wired circuit board  1  includes the insulating base layer  3 , the first conductive pattern  4  provided on the insulating base layer  3 , the intermediate insulating layer  5  provided on the insulating base layer  3  and covering the first conductive pattern  4  as an example of the insulating layer, the second conductive pattern  6  disposed on the intermediate insulating layer  5  as an example of the conductive pattern, and the insulating cover layer  7  provided on the intermediate insulating layer  5  and covering the second conductive pattern  6 . 
     The insulating base layer  3  has a generally flat plate (sheet) shape extending in the front-back direction. The insulating base layer  3  is made of an insulating material. Examples of the insulating material include synthetic resins such as polyimide resin, polyamide-imide resin, acrylic resin, polyether resin, nitrile resin, polyether sulfone resin, polyethylene terephthalate resin, polyethylenenaphthalate resin, and polyvinyl chloride resin, and preferably, polyimide resin is used. The insulating base layer  3  has a thickness of, for example, 1 μm or more, preferably 3 μm or more, and for example, 25 μm or less, preferably 15 μm or less. 
     The first conductive pattern  4  integrally includes a first wire  10 , and a first terminal (not shown) provided at both ends of the first wire  10 . 
     The first wire  10  integrally includes a first arc portion  11  having an arc shape, and two first linear portions  12  continued from both ends of the first arc portion  11 . 
     The first arc portion  11  is bent toward one side in the width direction as it approaches the back side. 
     The virtual circle (to be specific, virtual circle along the center in the width direction of the first arc portion  11 ) along the first arc portion  11  has a radius R1 of, for example, 5 μm or more, preferably 15 μm or more, and for example, 300 μm or less, preferably 100 μm or less. 
     The central angle α of the first arc portion  11  is not particularly limited, and for example, more than 0 degree, preferably 30 degrees or more, more preferably 45 degrees or more, and for example, 180 degrees or less, preferably 90 degrees or less. 
     The two first linear portions  12  are disposed so that their extension lines cross. Of the two first linear portions  12 , one inclines from the front end portion of the first arc portion  11  toward obliquely and forwardly one side in the width direction when viewed from the top, and the other inclines from the back end portion of the first arc portion  11  toward obliquely and backwardly one side in the width direction when viewed from the top. 
     The first wire  10  (first arc portion  11  and first linear portion  12 ) has a generally rectangular shape when viewed in cross section. The first wire  10  has two ridgeline portions  13  at the upper end portion. 
     The first conductive pattern  4  has a thickness of, for example, 1 μm or more, preferably 3 μm or more, and for example, 20 μm or less, preferably 12 μm or less. A width W1 of the first wire  10  is not particularly limited, to be specific, for example, 5 μm or more, preferably 8 μm or more, and for example, 200 μm or less, preferably 100 μm or less. 
     The intermediate insulating layer  5  is disposed at the top face of the insulating base layer  3  so as to cover the side face and a top face  16  of the first conductive pattern  4 . Although not shown, the intermediate insulating layer  5  allows the first terminal (not shown) of the first conductive pattern  4  to expose. The intermediate insulating layer  5  has a top face including a first flat face  14 , the inclination face  15 , and a second flat face  16 . 
     The first flat face  14  is a face parallel to a surface direction (direction along the surface of the insulating base layer  3 ), and is a face facing the top face of the insulating base layer  3  exposed from the first conductive pattern  4  in the thickness direction. 
     The inclination face  15  corresponds to the first wire  10 , continues from the first flat face  14 , and is a face inclined relative to the surface direction. To be specific, the inclination face  15  is a face that inclines (elevates) upward from the first flat face  14  in correspondence with the two ridgeline portions  13  of the first wire  10 . 
     The supplementary angle β to the angle β′ formed with the inclination face  15  and the first flat face  14 , that is, the gradient β of the inclination face  15  relative to the first flat face  14  is not particularly limited, and for example, the gradient β is 5 degrees or more, preferably 20 degrees or more, and for example, less than 90 degrees, preferably 60 degrees or less. 
     The inclination face  15  has, although described later, as shown in  FIG. 7  and  FIG. 8A , a second portion  28  that allows a reflected light B′ at a metal thin film  33  to reach a first portion  23  in a photoresist  25 . 
     As shown in  FIG. 1  and  FIG. 2 , the second portion  28  consists of the bent portion  17  as an example of the bent portion. To be specific, the second portion  28  preferably consists of only the bent portion  17 . 
     To be specific, the bent portion  17  is a portion at one side in the width direction (inner side portion) of the two inclination faces  15  corresponding to the two ridgeline portions  13 . The bent portion  17  has an arc shape similar to the arc shape of the ridgeline portion  13  when viewed from the top. The bent portion  17  is continuously bent toward one side in the width direction. The virtual circle along the bent portion  17  (to be specific, virtual circle along the center in the width direction of the bent portion  17 ) has a radius R2 of, for example, 5 μm or more, preferably 15 μm or more, and for example, 300 μm or less, preferably 100 μm or less. 
     The second flat face  16  corresponds to a top face  18  that connects the two ridgeline portions  13  of the first wire  10 , and is disposed to face above the top face  18  in spaced-apart relation. The second flat face  16  connects the upper end portion of the two inclination faces  15 . The second flat face  16  is parallel with the first flat face  14 . 
     The second conductive pattern  6  integrally includes a second wire  20  as an example of the wire, and a second terminal (not shown) provided at both ends of the second wire  20 . The second conductive pattern  6  further has a dummy wire  21  provided independently from the second wire  20 . 
     The second wire  20  consists of a second linear portion  22  extending in the front-back direction. The second linear portion  22  crosses the two first linear portions  12  when projected in the thickness direction. The second linear portion  22  is overlapped with a center CP of the arc of the bent portion  17  when projected in the thickness direction. To be specific, the central portion in the width direction of the second linear portion  22  is overlapped with the center CP of the arc of the bent portion  17  in the thickness direction. The second wire  20  is disposed at the top face of the first flat face  14  of the intermediate insulating layer  5 . The second wire  20  has a generally rectangular shape when viewed in cross section. 
     The dummy wire  21  is disposed to face the second wire  20  at the other side in the width direction in spaced-apart relation. The dummy wire  21  is provided corresponding to the first arc portion  11  of the first conductive pattern  4 , to be specific, provided corresponding to the ridgeline portion  13  at one side in the width direction in the first arc portion  11 . The dummy wire  21  has an arc shape similar to the arc shape of the ridgeline portion  13  at one side in the width direction when viewed from the top. Furthermore, the dummy wire  21  is overlapped with the bent portion  17  of the intermediate insulating layer  5  when viewed from the top. 
     Meanwhile, the dummy wire  21  is not provided corresponding to the two first linear portions  12  in the first conductive pattern  4 . That is, the dummy wire  21  deviates from the first linear portion  12  when projected in the thickness direction. 
     The dummy wire  21  is not provided corresponding to the ridgeline portion  13  at the other side in the width direction when viewed from the top. That is, the dummy wire  21  deviates from the ridgeline portion  13  at the other side in the width direction when projected in the thickness direction. 
     Then, the dummy wire  21  is provided corresponding to only the ridgeline portion  13  at one side in the width direction in the first arc portion  11 . That is, the dummy wire  21  is overlapped with the ridgeline portion  13  at one side in the width direction in the first arc portion  11  and one side portion in the width direction in the first arc portion  11  (excluding the above-described ridgeline portion  13 ). 
     The dummy wire  21  is disposed along the bent portion  17  (inclination face  15 ) of the intermediate insulating layer  5  when viewed in cross section, and has a generally wave shape when viewed in cross section. 
     The dummy wire  21  is a wire formed to prevent the reflected light B′ at the metal thin film  33  corresponding to the bent portion  17  in the step (4) described later from being focused on the first portion of the photoresist  25 , and is originally an unnecessary wire for the wired circuit board  1 , but is a necessary wire for the wired circuit board  1  having the bent portion  17 . 
     The dummy wire  21  is independent from the second wire  20  and not electrically connected to the second terminal (not shown). Therefore, the dummy wire  21  does not substantially have a function of wire. 
     The second conductive pattern  6  is made of the same conductive material as that of the first conductive pattern  4 . 
     The size of the second conductive pattern  6  is set suitably. The second conductive pattern  6  has a thickness of, for example, 1 μm or more, preferably 3 μm or more, and for example, 20 μm or less, preferably 12 μm or less. The second wire  20  has a width W2 of, for example, 5 μm or more, preferably 8 μm or more, and for example, 200 μm or less, preferably 100 μm or less. A width W3 of the dummy wire  21  is set so as to be overlapped with the bent portion  17  when projected in the thickness direction, to be specific, for example, 5 μm or more, preferably 10 μm or more, and for example, 100 μm or less, preferably 50 μm or less. The virtual circle along the dummy wire  21  has a radius R3 of, for example, 5 μm or more, preferably 15 μm or more, and for example, 300 μm or less, preferably 100 μm or less. The interval between the second wire  20  and the dummy wire  21  is, for example, 3 μm or more, preferably 5 μm or more, and for example, 100 μm or less, preferably 50 μm or less. 
     2. Method for Producing a Wired Circuit Board 
     Next, description is given below of the production method of the wired circuit board  1  with reference to  FIG. 3A  to  FIG. 6K . 
     The production method of the wired circuit board  1  includes a step (i) (ref:  FIG. 3A ), in which the insulating base layer  3  is prepared, a step (ii) (ref:  FIG. 3B ), in which the first conductive pattern  4  is provided on the insulating base layer  3 , and a step (1) (ref:  FIG. 3C ), in which the intermediate insulating layer  5  is provided on the insulating base layer  3  so as to cover the first conductive pattern  4 . 
     Furthermore, the production method of the wired circuit board  1  includes a step (2) (ref:  FIG. 4D ), in which the metal thin film  33  is provided at least on the inclination face  15  of the intermediate insulating layer  5 , a step (3) (ref:  FIG. 4E ), in which the photoresist  25  is provided on the metal thin film  33 , and a step (4) (ref:  FIG. 4F ), in which a photomask  24  is disposed so that the first portion  23 , i.e., an example of a portion, where the second conductive pattern  6  is to be provided in the photoresist  25 , is shielded from light, and the photoresist  25  is exposed to light through the photomask  24 . 
     Furthermore, the production method of the wired circuit board  1  includes a step (5) (ref:  FIG. 5G ), in which the first portion  23  is removed to expose the metal thin film  33  corresponding to the first portion  23 , and a step (6) (ref: phantom line in  FIG. 5H ), in which the second conductive pattern  6  is provided on the metal thin film  33  exposed from the photoresist  25 . 
     Furthermore, the production method of the wired circuit board  1  includes a step (iii) (ref:  FIG. 5I ), in which the photoresist  25  is removed, a step (iv) (ref:  FIG. 6J ), in which the metal thin film  33  corresponding to the photoresist  25  is removed, and a step (v) (ref:  FIG. 6K ), in which the insulating cover layer  7  is provided on the intermediate insulating layer  5  so as to cover the second conductive pattern  6 . 
     In the production method of the wired circuit board  1 , the step (i) to step (ii), the step (1) to step (6), and the step (iii) to step (v) are performed sequentially. In the following, the above-described steps are described in detail. 
     2-1. Step (i) 
     As shown in  FIG. 3A , in the step (i), the insulating base layer  3  is prepared. 
     2-2. Step (ii) 
     As shown in  FIG. 3B , in the step (ii), the first conductive pattern  4  is provided on the insulating base layer  3 . 
     2-3. Step (1) 
     As shown in  FIG. 3C , in the step (1), the intermediate insulating layer  5  is provided on the insulating base layer  3  so as to cover the first conductive pattern  4 . 
     To provide the intermediate insulating layer  5  on the insulating base layer  3 , for example, varnish of a photosensitive insulating material is applied to the top face of the insulating base layer  3 , exposed to light and developed, and thereafter, as necessary, heated. Alternatively, the intermediate insulating layer  5  preformed into a pattern which allows a first terminal, which is not shown, to be exposed is allowed to adhere onto the insulating base layer  3  with an adhesive, which is not shown, interposed therebetween. 
     At this time, in the intermediate insulating layer  5  corresponding to the first conductive pattern  4 , the inclination face  15  and the second flat face  16  are generated. 
     In this manner, the intermediate insulating layer  5  having the inclination face  15  including the bent portion  17  (ref:  FIG. 1 ) is provided. 
     2-4. Step (2) 
     As shown in  FIG. 4D , in the step (2), the metal thin film  33  is provided at least on the inclination face  15  of the intermediate insulating layer  5 . 
     The metal thin film  33  can serve as a seed film (feeding layer) in the additive method of the step (6) (described later, ref:  FIG. 5H ). The metal thin film  33  is a layer that can be integrated with the second conductive pattern  6  when the second conductive pattern  6  is obtained in the additive method (ref:  FIG. 2 ). 
     The metal thin film  33  is provided on the entire surface of, for example, the top face (including the first flat face  14 , the inclination face  15  (including the bent portion  17 ), and the second flat face  16 ) of the intermediate insulating layer  5 . 
     The metal thin film  33  is made of a metal material. Examples of the metal material include copper, chromium, nickel, and an alloy thereof, and preferably, copper and chromium are used. The metal thin film  33  can be made of a single or a plurality of layers (not shown in  FIG. 4D ). Preferably, the metal thin film  33  consists of two layers of a first thin film (to be specific, chromium thin film), and a second thin film (copper thin film) provided thereon. 
     The metal thin film  33  is in conformity with the top face of the intermediate insulating layer  5 . Therefore, in the metal thin film  33 , the top face of the portion corresponding to the first flat face  14  and the second flat face  16  of the intermediate insulating layer  5  is parallel with the first flat face  14  and the second flat face  16 , that is, is along the surface direction. Meanwhile, in the metal thin film  33 , the top face of the portion corresponding to the inclination face  15  (including the bent portion  17 ) is parallel with the inclination face  15  (including the bent portion  17 ) of the intermediate insulating layer  5 , that is, inclined relative to the surface direction. 
     The metal thin film  33  has a thickness of, for example, 10 nm or more, preferably 30 nm or more, and for example, 300 nm or less, preferably 200 nm or less. When the metal thin film  33  consists of two layers of the first thin film and the second thin film, the first thin film has a thickness of, for example, 10 nm or more, and 100 nm or less, and the second thin film has a thickness of, for example, 50 nm or more, and 200 nm or less. 
     To provide the metal thin film  33  on the intermediate insulating layer  5 , for example, a sputtering method and a plating method are used, and preferably, a sputtering method is used. 
     2-5. Step (3) 
     As shown in  FIG. 4E , in the step (3), the photoresist  25  is provided on the metal thin film  33 . 
     The photoresist  25  is a negative type photoresist (negative photoresist). The negative type photoresist is a resist that allows the portion which is exposed to the light at the time of exposure to remain in developing thereafter, and meanwhile, the portion which is shielded from light at the time of exposure (portion to which light is not applied) to be removed in developing thereafter. The photoresist  25  includes, for example, dry film photoresist (DFR). The photoresist  25  can serve as, as shown in  FIG. 5H , a plating resist in the plating in the step (6). 
     The photoresist  25  can allow the light in the step (4) (ref:  FIG. 4F ) (e.g., ultraviolet ray, etc.) to partially pass through, to be specific, the photoresist  25  has an ultraviolet ray transmissivity of, for example, 10% or more, preferably 20% or more, and for example, 60% or less, preferably 50% or less. 
     The above-described photoresist  25  is disposed on the entire top face of the metal thin film  33 . 
     At that time, the dry film photoresist is pressed (pushed onto) using, for example, a flat plate. Therefore, the top face of the photoresist  25  is a flat face. 
     The thickness of the photoresist  25  is not particularly limited, and is, for example, 10 μm or more, and for example, 50 μm or less, preferably 30 μm or less. 
     2-6. Step (4) 
     As shown in  FIG. 4F , in the step (4), the photomask  24  is disposed so that the first portion  23  in the photoresist  25  and a third portion  29  corresponding to the second portion  28  in the photoresist  25  are shielded from light, thereby exposing the photoresist  25  to light through the photomask  24 . 
     The first portion  23  is a portion that is to be shielded (should be shielded) from light in the photoresist  25  in the step (4). The first portion  23  is a portion to be removed (should be removed), as shown in  FIG. 5G , in the following step (5). Furthermore, the first portion  23  is a portion, as shown in  FIG. 5H , where the second wire  20  is to be provided at openings  30  (described later) of the photoresist  25  in the following step (6) (charged with). To be specific, the first portion  23  is a portion where the second wire  20  and the second terminal (not shown) are to be provided in the openings  30  of the photoresist  25  in the following step (6) (charged with). 
     Meanwhile, the third portion  29  is a portion that is shielded from light in the photoresist  25  in the step (4). The third portion  29  is also a portion where the dummy wire  21  is provided in the openings  30  of the photoresist  25  in the following step (6) (charged with). 
     The photomask  24  includes a translucent portion  26  that allows light from above to pass through below, and a light shield portion  27  that allows light from above to be shielded to below. 
     The light shield portion  27  has a first light shield portion  31  corresponding to the first portion  23  and a second light shield portion  32  corresponding to the third portion  29 . 
     In the step (4), the photomask  24  is disposed so that the first light shield portion  31  faces the first portion  23 , the second light shield portion  32  faces the third portion  29 , and the translucent portion  26  faces the portion other than the first portion  23  and the third portion  29  in the photoresist  25 . The second light shield portion  32  is overlapped with the second portion  28  of the intermediate insulating layer  5  when projected in the thickness direction. The translucent portion  26  is overlapped with the first flat face  14  and the second flat face  16  of the intermediate insulating layer  5  when projected in the thickness direction. 
     The photomask  24  is disposed above and faces the photoresist  25  in spaced-apart relation. Although not shown in  FIG. 4F , the photomask  24  can also be directly contacted with the top face of the photoresist  25 . 
     In this manner, the photomask  24  is disposed so that the first portion  23  and the third portion  29  in the photoresist  25  are shielded from light. Furthermore, the photomask  24  is disposed so that the portion other than the first portion  23  and the third portion  29  in the photoresist  25  allows light to pass through. 
     Then, in the step (4), the photoresist  25  is exposed to light through the photomask  24 . 
     To expose the photoresist  25  to light, light is applied to the photomask  24  from the light source disposed above the photomask  24 . The wavelength of the light is, for example, 100 nm or more, preferably 350 nm or more, and for example, 800 nm or less, preferably 450 nm or less. The application (exposure) amount is, for example, 100 mJ/cm 2  or more and 800 mJ/cm 2  or less. 
     [1] Then, light A applied to the first light shield portion  31  of the photomask  24  is shielded with the first light shield portion  31 , and does not reach the first portion  23  of the photoresist  25 . 
     [2] Meanwhile, light B applied to the second light shield portion  32  of the photomask  24  is shielded with the second light shield portion  32 , and does not reach the third portion  29  of the photoresist  25 . Therefore, the light B also does not reach the metal thin film  33  (metal thin film  33  facing the second portion  28  of the photoresist  25 ) that is positioned below the third portion  29 . 
     2-7. Step (5) 
     As shown in  FIG. 5G , in the step (5), the first portion  23  (ref:  FIG. 4F ) in the photoresist  25  is removed. Along with this, the third portion  29  (ref:  FIG. 4F ) in the photoresist  25  is removed. 
     To be specific, first, as necessary, the photoresist  25  after exposure is heated (heating after exposure). 
     Then, the photoresist  25  is developed with a developer. In this manner, the portion other than the first portion  23  and the third portion  29  in the photoresist  25  is left, and only the first portion  23  and the third portion  29  are removed. That is, in the photoresist  25 , the openings  30  corresponding to the first portion  23  and the third portion  29  are formed. The openings  30  penetrate the photoresist  25  in the thickness direction. 
     In this manner, the metal thin film  33  corresponding to the first portion  23  and the third portion  29 , that is, the metal thin film  33  facing the openings  30  is exposed. 
     Thereafter, as necessary, the photoresist  25  is cured by heating. 
     2-8. Step (6) 
     As shown in the phantom line of  FIG. 5H , in the step (6), first, the second conductive pattern  6  is provided on the metal thin film  33  exposed from the photoresist  25 . 
     To provide the second conductive pattern  6  on the metal thin film  33 , electrolytic plating in which electricity is supplied from the metal thin film  33  is used. 
     At this time, the photoresist  25  is used as a plating resist. The metal thin film  33  is used as a feeding layer. 
     In this manner, the second conductive pattern  6  is formed as a pattern having the second wire  20 , the second terminal, and the dummy wire  21 . 
     2-9. Step (iii) 
     As shown in  FIG. 5I , in the step (iii), the photoresist  25  is removed. 
     To be specific, the photoresist  25  is removed, for example, by wet etching. 
     2-10. Step (iv) 
     As shown in  FIG. 6J , in the step (iv), the metal thin film  33  corresponding to the photoresist  25  (ref:  FIG. 5H ) is removed. 
     To be specific, the metal thin film  33  positioned below the photoresist  25  is removed, for example, by peeling. 
     2-11. Step (v) 
     As shown in  FIG. 6K , in the step (v), the insulating cover layer  7  is provided in a pattern such that in the second conductive pattern  6 , the second wire  20  and the dummy wire  21  are covered and the second terminal (not shown) is exposed. 
     The wired circuit board  1  including the insulating base layer  3 , the first conductive pattern  4 , the intermediate insulating layer  5 , the metal thin film  33 , the second conductive pattern  6 , and the insulating cover layer  7  is produced in this manner. 
     In the wired circuit board  1 , the metal thin film  33  can be integrated with the second conductive pattern  6 , to be specific, the metal thin film  33  can be incorporated as a part of the second conductive pattern  6 . At that time, as shown in  FIG. 1 , there may be a case where the metal thin film  33  cannot be distinguished with the second conductive pattern  6  clearly. 
     Use of such a wired circuit board  1  is not particularly limited, and for example, it is used as various wired circuit boards: a suspension board with circuit included in a hard disk drive and including the metal supporting board (ref: phantom line in  FIG. 2 ), and a flexible wired circuit board not including the metal supporting board and having flexibility. In particular, the wired circuit board  1  is suitably used in a suspension board with circuit that requires a high density wire (conductive pattern), and is a suspension board with circuit having the above-described dummy wire  21  in the head mounting region. 
     As shown in  FIG. 7 , even when producing the wired circuit board  1  not having the dummy wire  21  (ref:  FIG. 1 ), as shown in  FIG. 8A  and  FIG. 8B , the step (4) and the step (5) are conducted. 
     As shown in  FIG. 7 , in the wired circuit board  1 , the second conductive pattern  6  does not have the dummy wire  21 , and includes the second wire  20  and the second terminal (not shown). 
     In the step (4), as shown in  FIG. 8A , in the photomask  24 , the light shield portion  27  does not have the second light shield portion  32  (ref:  FIG. 4F ) corresponding to the third portion  29 , while having only the first light shield portion  31  corresponding to the first portion  23 . 
     [1] When light is applied to the photomask  24  from the light source, the light A applied to the first light shield portion  31  of the photomask  24  is shielded with the first light shield portion  31 , and does not reach the first portion  23  of the photoresist  25 . 
     [2] However, the light B applied to the translucent portion  26  facing the third portion  29  passes through the translucent portion  26 , and reaches the third portion  29 . Then, the portion of the light B passes through the third portion  29 , and reflects at the top face of the metal thin film  33  corresponding to the second portion  28  to produce the reflected light B′. The reflected light B′ passes through the photoresist  25  toward obliquely and upwardly one side in the width direction when viewed in cross section, and reaches the first portion  23  of the photoresist  25 . 
     Then, as shown in  FIG. 8B , in the step (5), the first portion  23  cannot be completely removed, that is, the first portion  23  is partially or completely left. Thus, in the photomask  24 , the openings  30  (ref:  FIG. 5G ) corresponding to the first portion are not formed. As a result, the metal thin film  33  corresponding to the first portion  23  is covered. 
     Then, the second wire  20  (ref: phantom line) cannot be formed. That is, the second conductive pattern  6  having deformation is formed. 
     However, with the production method of the first embodiment, as shown in  FIG. 4F , in the step (4), the photomask  24  is disposed so that the photoresist  25  facing the second portion  28  of the intermediate insulating layer  5 , that is, the third portion  29  is shielded from light. Therefore, even when the inclination face  15  has the second portion  28  that allows the reflected light B′ that reflects at the metal thin film  33  to reach the first portion  23 , in the step (4), the third portion  29  is shielded from light, so that the reflected light B′ can be prevented from reaching the first portion  23 . That is, the occurrence of the reflected light B′ can be prevented. 
     As a result, as shown in  FIG. 4F , in the step (4), the first portion  23  is surely shielded from light, and the photoresist  25  other than the first portion  23  (and the third portion  29 ) can be exposed to light. Thereafter, as shown in  FIG. 5G , in the step (5), the metal thin film  33  corresponding to the first portion  23  is surely exposed and subsequently, as shown in  FIG. 5H , in the step (6), the second wire  20  in which deformation is suppressed can be surely provided. 
     Therefore, the second conductive pattern  6  having high reliability can be provided with a high degree of freedom. 
     Accordingly, the wired circuit board  1  having a high degree of freedom with excellent connection reliability can be produced. 
     As shown in  FIG. 7  and  FIG. 8A , when the second portion  28  of the intermediate insulating layer  5  has the bent portion  17  bending in one direction when viewed from the top, the reflected light B′, as shown in  FIG. 7 , is focused toward the first portion  23  corresponding to the center CP when viewed from the top. That is, when viewed from the top, the metal thin film  33  corresponding to the second portion  28  (bent portion  17 ) works as a concave lens, and the reflected light B′ is focused on the point of the first portion  23 . Therefore, the amount of light at the first portion  23  is relatively high. To be specific, the amount of light at the first portion  23  is the amount of light that allows the first portion  23  to remain in the step (5) shown in  FIG. 8B , or even more. 
     Then, as shown in  FIG. 8B , in the step (5), the metal thin film  33  corresponding to the first portion  23  cannot be exposed, and as shown in  FIG. 8C , in the step (6), the second conductive pattern  6  having deformation is provided. That is, the reflected light B′ corresponding to the bent portion  17  is focused on the first portion  23  of the photoresist  25 , thereby revealing deformation of the second wire  20 . 
     However, with the production method of the first embodiment, as shown in  FIG. 4F , in the step (4), the photomask  24  is disposed so that the third portion  29  that is the photoresist  25  facing the second portion  28  is shielded from light, and therefore, in the step (4), the first portion  23  can be surely shielded from light. Thereafter, as shown in  FIG. 5G , in the step (5), the metal thin film  33  corresponding to the first portion  23  is surely exposed. Subsequently, as shown in  FIG. 5H , in the step (6), the second conductive pattern  6  including the second wire  20  in which deformation is suppressed can be surely provided. 
     With the production method of the first embodiment, as shown in  FIG. 4F , in the step (4), the third portion  29 , where the dummy wire  21  is to be provided in the photoresist  25 , is overlapped with the second portion  28  of the intermediate insulating layer  5  when viewed from the top. Therefore, in the step (4), the third portion  29  can be surely shielded from light and furthermore, the second portion  28  can be shielded from light. Thus, the occurrence of the reflected light B′ in the second portion  28  that is overlapped with the third portion  29  can be prevented. Thus, the exposure to light (ref:  FIG. 8A ) of the first portion  23  caused by the reflected light B′ in the second portion  28  is surely prevented, and the second wire  20  can be surely provided. 
     In the wired circuit board  1 , the second conductive pattern  6  has the dummy wire  21  and the dummy wire  21  is overlapped with the bent portion  17  when viewed from the top, so that as shown in  FIG. 4F , in photo processing of the step (4), by preventing the unintended reflection corresponding to the bent portion  17  (generation of reflected light B′), the occurrence of the light shielding failure in the portion corresponding to the second wire  20  can be prevented. Therefore, the reliability of the second wire  20  is improved. 
     4. Modified Example of First Embodiment 
     In the first embodiment, the bent portion  17  as an example of the bent portion is used. Alternatively, for example, the bent portion is not limited to the bent portion  17 . 
     Although not shown, a curved portion that is curved at a predetermined angle in one direction in a plurality of times or a single time (or a curving portion that curves at a predetermined angle in one direction) can be also used. In such a case, the curved portion (curving portion) includes a part of vertexes and at least two sides continued therefrom of a polygon. The above-described angle, is for example, more than 0 degree, preferably 30 degrees or more, and for example, 90 degrees or less, preferably 60 degrees or less. 
     As shown in  FIG. 1 , the shape of the dummy wire  21  is a generally arc shape when viewed from the top, and the shape thereof is not limited to the above-described shape as long as the dummy wire  21  is overlapped with the second portion  28  in the thickness direction. 
     The dummy wire  21  is overlapped with only the second portion  28  corresponding to the first arc portion  11  in the thickness direction, and furthermore, can be also overlapped with the second portion  28  corresponding to the first linear portion  12 . 
     Second Embodiment 
     In the second embodiment, for the members and steps that are the same as the first embodiment, the same reference numerals are given and detailed descriptions thereof are omitted. 
     In the first embodiment, the negative type photoresist  25  is used, and the additive method is used to form the second conductive pattern  6 . 
     However, in the second embodiment, the positive type photoresist  25  is used, and the subtractive method is used to form the second conductive pattern  6 . 
     4-1. Method for Producing a Wired Circuit Board 
     The production method of the wired circuit board  1  of the second embodiment includes a step (i) (ref:  FIG. 3A ), in which the insulating base layer  3  of the first embodiment is prepared, a step (ii) (ref:  FIG. 3B ), in which the first conductive pattern  4  is provided, and a step (1) (ref:  FIG. 3C ), in which the intermediate insulating layer  5  is provided. 
     The production method of the wired circuit board  1  of the second embodiment further includes a step (2) (ref:  FIG. 9A ), in which the conductive layer  34  is provided at least on the inclination face  15  of the intermediate insulating layer  5 , a step (3) (ref:  FIG. 9B ), in which the photoresist  25  is provided on the conductive layer  34 , and a step (4) (ref: arrow in  FIG. 9B ), in which the photomask  24  is disposed so that the first portion  23  of the photoresist  25  is shielded from light, and the photoresist  25  is exposed to light through the photomask  24 . 
     Furthermore, the production method of the wired circuit board  1  of the second embodiment includes a step (5) (ref:  FIG. 9C ), in which the portion other than the first portion  23  is removed so as to leave the first portion  23  in the photoresist  25 , and a step (6) (ref: phantom line in  FIG. 10D ), in which the conductive layer  34  exposed from the photoresist  25  is removed to form the second conductive pattern  6 . 
     Furthermore, the production method of the wired circuit board  1  includes a step (iii) (ref:  FIG. 10E ), in which the photoresist  25  is removed, and a step (v) (ref:  FIG. 10F ), in which the insulating cover layer  7  is provided. 
     4-2. Step (1) and Step (2) 
     In the second embodiment, as shown in  FIG. 9A  and  FIG. 9B , the step (1) and the step (2) are sequentially conducted. Alternatively, the step (1) and the step (2) are conducted, for example, simultaneously. In such a case, the two-layer substrate in which the intermediate insulating layer  5  and the conductive layer  34  are laminated is provided on the insulating base layer  3  so as to cover the first conductive pattern  4 . 
     The conductive layer  34  is disposed on the entire top face including the first flat face  14 , the inclination face  15 , and the second flat face  16  of the intermediate insulating layer  5 . The conductive layer  34  extends along the top face of the intermediate insulating layer  5  along the surface direction. The conductive layer  34  is made of the same conductive material as that of the second conductive pattern  6 . The thickness of the conductive layer  34  is the same as the thickness of the second conductive pattern  6 . 
     4-3. Step (4) 
     As shown in  FIG. 9B , in the step (4), the photomask  24  is disposed so that the first portion  23  and the third portion  29  are shielded from light in the photoresist  25 . 
     The photoresist  25  is a positive type photoresist (positive photoresist). The positive type photoresist is a resist that allows the portion to which light is applied at the time of exposure to be removed in developing thereafter, and meanwhile, the portion which is shielded from light at the time of exposure (portion to which light is not applied) to remain in developing thereafter. 
     Thereafter, as shown in the arrow of  FIG. 9B , the photoresist  25  is exposed to light through the photomask  24 . 
     [1] Then, the light A applied to the first light shield portion  31  of the photomask  24  is shielded with the first light shield portion  31 , and does not reach the first portion  23 . 
     [2] Meanwhile, the light B applied to the second light shield portion  32  of the photomask  24  is shielded with the second light shield portion  32 , and does not reach the third portion  29  in the photoresist  25 . Thus, the light B does not reach the conductive layer  34  (conductive layer  34  facing the second portion  28 ) positioned below the third portion  29 . 
     4-4. Step (5) 
     As shown in  FIG. 9C , in the step (5), the photoresist  25  after exposure is developed with, for example, a developer, and the photoresist  25  other than the first portion  23  and the third portion  29  is removed so as to leave the first portion  23  and the third portion  29 . 
     4-5. Step (6) 
     As shown in  FIG. 10D , in the step (6), the conductive layer  34  exposed from the photoresist  25  is removed. 
     For example, the photoresist  25  is used as an etching resist to conduct etching on the conductive layer  34 . 
     In this manner, the second conductive pattern  6  having the second wire  20 , the second terminal (not shown), and the dummy wire  21  is formed. 
     4-6. Step (iii) 
     As shown in  FIG. 10E , in the step (iii), the photoresist  25  is removed, for example, by peeling. 
     5. Wired Circuit Board 
     The wired circuit board  1  produced by the above-described production method includes the insulating base layer  3 , the first conductive pattern  4 , the intermediate insulating layer  5 , the second conductive pattern  6 , and the insulating cover layer  7  covering the second conductive pattern  6 . The wired circuit board  1  in the second embodiment does not include the metal thin film  33  (ref:  FIG. 2 ) unlike the first embodiment. 
     Meanwhile, the wired circuit board  1  in the second embodiment may include an adhesive layer (not shown) between the second conductive pattern  6  and the intermediate insulating layer  5  so as to allow them to adhere. 
     With the production method of the second embodiment, as shown in  FIG. 9B , in the step (4), the photomask  24  is disposed so that the third portion  29  that is the photoresist  25  facing the second portion  28  is shielded from light. Therefore, even when the inclination face  15  has the second portion  28  that allows the reflected light B′ that reflects at the conductive layer  34  to reach the first portion  23 , in the step (4), the third portion  29  is shielded from light, so that the reflected light B′ can be prevented from reaching the first portion  23 . That is, the occurrence of the reflected light B′ can be prevented. 
     As a result, as shown in  FIG. 9B , in the step (4), the first portion  23  is surely shielded from light, and the photoresist  25  can be exposed to light. Thereafter, as shown in  FIG. 10D , in the step (5), the photoresist  25  other than the first portion  23  and the third portion  29  is surely removed so as to leave the first portion  23  and the third portion  29 , and subsequently, as shown in  FIG. 10E , in the step (6), the second wire  20  in which deformation is suppressed can be surely provided. 
     Therefore, the second conductive pattern  6  having high reliability can be provided with a high degree of freedom. 
     As a result, the wired circuit board  1  having a high degree of freedom with excellent connection reliability can be produced. 
     Third Embodiment 
     In the third embodiment, for the members and steps that are the same as the first and second embodiments, the same reference numerals are given and detailed descriptions thereof are omitted. 
     1. Wired Circuit Board 
     As shown in  FIG. 1  and  FIG. 2 , the wired circuit board  1  of the first embodiment includes the dummy wire  20  that is independent from the second wire  20 . 
     However, as shown in  FIG. 11  and  FIG. 12 , in the third embodiment, the wired circuit board  1  includes a dummy portion  35  that continues from the second wire  20 . 
     1-1. Dummy Portion 
     The dummy portion  35  is included in the second conductive pattern  6 . The dummy portion  35  is a projection portion that projects from the other end portion in the width direction of the second linear portion  22  toward the other side in the width direction. The dummy portion  35  has a generally triangular shape with one vertex in a bent shape. The dummy portion  35  (right side, projection piece) has a shape similar to the first arc portion  11  of the first wire  10 . The dummy portion  35  continues from the second linear portion  22  in the width direction. 
     The maximum length in a projection direction (width direction) of the dummy portion  35  is set suitably, for example, 5 μm or more, preferably 15 μm or more, and for example, 300 μm or less, preferably 100 μm or less. 
     2-1. Step (4) 
     In the production method of the wired circuit board  1 , as shown in  FIG. 13A , in the step (4), the photomask  24  having the light shield portion  27  that has the first light shield portion  31  and the second light shield portion  32  continuing in the width direction each other is disposed. 
     As shown in the arrow of  FIG. 13A , light D applied to the light shield portion  27  including the first light shield portion  31  and the second light shield portion  32  does not reach the first portion  23  and the third portion  29 . Thus, the light D does not reach the metal thin film  33  positioned below the third portion  29 . 
     2-2. Step (5) 
     As shown in  FIG. 13B , the first portion  23  and the third portion  29  are collectively removed. 
     In this manner, the large opening  30  corresponding to the first portion  23  and the third portion  29  is formed in the photoresist  25 . 
     2-3. Step (6) 
     As shown in  FIG. 13C , the second conductive pattern  6  is provided on the metal thin film  33  exposed from the opening  30  of the photoresist  25 . 
     2-4. Step (iii) 
     As shown in  FIG. 14D , in the step (iii), the photoresist  25  is removed. 
     2-5. Step (iv) 
     As shown in  FIG. 14E , in the step (iv), the metal thin film  33  corresponding to the photoresist  25  (ref:  FIG. 13C ) is removed. 
     2-6. Step (v) 
     As shown in  FIG. 14F , in the step (v), the insulating cover layer  7  is provided in a pattern which covers the second wire  20  and the dummy portion  35  of the second conductive pattern  6  and exposes the second terminal (not shown). 
     With the production method of the third embodiment, as shown in  FIG. 13A , in the step (4), the third portion  29 , where the dummy portion  35  is to be provided in the photoresist  25 , is overlapped with the second portion  28  when viewed from the top. Accordingly, in the step (4), the third portion  29  can be surely shielded from light. Therefore, the occurrence of the reflected light B′ (ref:  FIG. 8A ) in the second portion  28  that is overlapped with the third portion  29  can be prevented. As a result, the exposure to light of the first portion  23  caused by the reflected light B′ in the second portion  28  is surely prevented, and the second wire  20  can be surely provided. 
     Furthermore, as shown in  FIG. 11 , the dummy portion  35  continues from the second wire  20 , so that a simpler configuration can be achieved than the first embodiment (ref:  FIG. 1 ) in which the second wire  20  and the dummy wire  21  are separately provided. 
     3. Modified Example of Third Embodiment 
     The wired circuit board  1  of the third embodiment is produced using the negative type photoresist  25 . In the modified example, though not shown, the wired circuit board  1  of the third embodiment can be also produced using the positive type photoresist  25 . 
     As shown in  FIG. 11 , the shape of the dummy portion  35  is a generally triangular shape when viewed from the top, and the shape thereof is not limited to the above-described shape as long as the dummy portion  35  is overlapped with the second portion  28  in the thickness direction. 
     The dummy portion  35  is overlapped with only the second portion  28  corresponding to the first arc portion  11 , and furthermore, can be also overlapped with the second portion  28  corresponding to the first linear portion  12 . 
     Fourth Embodiment 
     In the fourth embodiment, for the members and steps that are the same as the first to third embodiments, the same reference numerals are given and detailed descriptions thereof are omitted. 
     In the first embodiment to the third embodiment, as shown in  FIG. 1  and  FIG. 2 , the first conductive pattern  4  has the first arc portion  11 . 
     However, as shown in  FIG. 15 , in the fourth embodiment, the first conductive pattern  4  has a third linear portion  36 . 
     1. First Conductive Pattern 
     In the first conductive pattern  4 , when viewed from the top, the first wire  10  integrally includes the two first linear portions  12  that are relatively far from the second linear portion  22  of the second conductive pattern  6 , the third linear portion  36  that is closer relative to the second linear portion  22 , and a second connecting portion  37  that connects the first linear portion  12  and the third linear portion  36 . 
     The two first linear portions  12  are disposed in spaced-apart relation in the front-back direction. Each of the two first linear portions  12  extends in the front-back direction. To be specific, each of the two first linear portions  12  is parallel with the second linear portion  22  of the second conductive pattern  6  when viewed from the top. The two first linear portions  12  are overlapped when projected in the front-back direction. That is, a distance L0 between one first linear portion  12  and the second linear portion  22  in the width direction is the same as the distance L0 between the other first linear portion  12  and the second linear portion  22  in the width direction. 
     The third linear portion  36  is disposed between the two first linear portions  12  when projected in the width direction. The third linear portion  36  extends in the front-back direction. The third linear portion  36  is parallel with the first linear portion  12 . The third linear portion  36  is parallel with the second linear portion  22  of the second conductive pattern  6 . The third linear portion  36  is positioned at one side in the width direction relative to the two first linear portions  12  when projected in the front-back direction. That is, when viewed from the top, a distance (interval) L1 between the third linear portion  36  and the second linear portion  22  in the width direction is smaller than the distance (interval) L0 between the two first linear portions  12  and the second linear portion  22  in the width direction. 
     When viewed from the top, the distance (interval) L1 between the third linear portion  36  and the second linear portion  22  in the width direction is, for example, more than 7.5 μm, and for example, 22.5 μm or less, preferably 17.5 μm or less, more preferably 12.5 μm or less. The distance L1 (μm) satisfies the formula (2).
 
 L 1≤−2× W 2+37.5  (2)
 
W2 is a width of the second linear portion  22  of the second conductive pattern  6  and an example of the width W of the wire. The unit is μm.
 
     That is, as the width W2 of the second linear portion  22  becomes smaller, the distance L1 is allowed to be long. 
     When the distance L1 and the width W2 of the second linear portion  22  described above do not satisfy the above-described formula (2), that is, the left side is larger than the right side in the formula (2), deformation of the second wire  20  caused by the reflected light B′ reaching the first portion  23  of the photoresist  25  can be solved without providing the dummy wire  21  in the wired circuit board  1 . Then, providing the dummy wire  21  may have no significance. 
     Meanwhile, when viewed from the top, the distance (interval) L0 between the first linear portion  12  and the second linear portion  22  in the width direction is, for example, 25 μm or more, preferably 30 μm or more, and for example, 1000 μm or less. 
     The second connecting portion  37  independently includes a portion connecting the front end portion of the third linear portion  36  to the back end portion of the front-side first linear portion  12 , and a portion connecting the back end portion of the third linear portion  36  to the front end portion of the back-side first linear portion  12 . 
     Accordingly, the first wire  10  bends toward one side in the width direction, when reaching from the front-side first linear portion  12  to the front-side second connecting portion  37 ; next, bends toward the other side in the width direction, when reaching from the front-side second connecting portion  37  to the third linear portion  36 ; then, bends toward the other side in the width direction, when reaching from the third linear portion  36  to the back-side second connecting portion  37 ; and bends toward one side in the width direction, when reaching from the back-side second connecting portion  37  to the back-side first linear portion  12 . 
     2. Intermediate Insulating Layer 
     As shown in  FIG. 16C  and  FIG. 17C , the intermediate insulating layer  5  has the inclination face  15  corresponding to the ridgeline portion  13  at one side in the width direction of the first wire  10  (including the third linear portion  36 ). 
     A distance L2 (example of L) between one end portion in the width direction (rising portion) of the inclination face  15  corresponding to the third linear portion  36  and the other end portion in the width direction of the second linear portion  22  is, more than 5 μm, and 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less. 
     When the distance L2 is more than the above-described upper limit, deformation of the second wire  20  caused by the reflected light B′ reaching the first portion  23  of the photoresist  25  can be solved without providing the dummy wire  21  in the wired circuit board  1 . Then, providing the dummy wire  21  may have no significance. 
     Along with the width W2 (μm) of the second linear portion  22 , the distance L2 (μm) satisfies the formula (1).
 
 L 2≤−2× W 2+35  (1)
 
     That is, as the width W2 of the second linear portion  22  becomes smaller, the distance L2 is allowed to be long. In the graph shown in  FIG. 25 , the distance L2 and the width W2 include the straight line of “L2=−2×W2+35” and should be in the left-lower region of the straight line. 
     When the distance L2 and the width W2 of the second linear portion  22  described above do not satisfy the above-described formula (1), that is, the left side is larger than the right side in the formula (1), deformation of the second wire  20  caused by the reflected light B′ reaching the first portion  23  of the photoresist  25  can be solved without providing the dummy wire  21  in the wired circuit board  1 . Then, providing the dummy wire  21  may have no significance. 
     On the other hand, when the distance L1 and the width W2 of the second linear portion  22  satisfy the above-described formula (2), as shown in  FIG. 8A , in the width W2 of the second linear portion  22 , the distance L1 between the third linear portion  36  and the metal thin film  33  corresponding to the first portion  23  is a distance (short distance) of the reflected light B′ reaching the first portion  23  when viewed from the top. Therefore, by providing the dummy wire  21 , deformation of the second linear portion  22  having the width W2 needs to be prevented. 
     A length (=L2−L1) obtained by subtracting the distance L1 from the distance L2 described above is, for example, more than 0 μm, preferably 1 μm or more, and for example, 10 pin or less. 
     Meanwhile, a distance L3 between one end portion in the width direction (rising portion) of the inclination face  15  corresponding to the first linear portion  12  and the other end portion in the width direction of the second linear portion  22  is, for example, 20 μm or more, furthermore 25 μm or more, and for example, 1000 μm or less. 
     3. Second Conductive Pattern 
     3-1. Second Linear Portion 
     The second linear portion  22  has the width W2 of, for example, 15 μm or less, preferably 12.5 μm or less, more preferably 10 μm or less, and for example, 1 μm or more, preferably 5 μm or more. 
     When the width W2 of the second linear portion  22  is more than the above-described upper limit, deformation of the second wire  20  caused by the reflected light B′ reaching the first portion  23  of the photoresist  25  can be solved without providing the dummy wire  21  in the wired circuit board  1 . Then, providing the dummy wire  21  may have no significance. 
     3-2. Dummy Wire 
     The dummy wire  21  is provided corresponding to the third linear portion  36 . To be specific, the dummy wire  21  is provided corresponding to the ridgeline portion  13  at one side in the width direction of the third linear portion  36 . The dummy wire  21  has a generally linear shape similar to the linear shape of the ridgeline portion  13  at one side in the width direction. Furthermore, the dummy wire  21  is overlapped with the inclination face  15  when viewed from the top. The dummy wire  21  is disposed next to the second linear portion  22  at the other side in the width direction in spaced-apart relation when viewed from the top. The dummy wire  21  is shorter than the second linear portion  22  in the front-back direction. 
     Meanwhile, the dummy wire  21  is not provided corresponding to the first linear portion  12 . The dummy wire  21  is not overlapped with the first linear portion  12  when projected in the thickness direction. 
     4. Method for Producing a Wired Circuit Board 
     The production method of the wired circuit board  1  of the fourth embodiment is the same production method as that of the first embodiment. 
     In the fourth embodiment, when the distance L2 and the width W2 described above are set in the above-described range and the above-described formula (1) is satisfied, the photomask  24  does not have the second light shield portion  32 , and upon performing the step (4), as shown in  FIG. 8A , the reflected light B′ at the inclination face  15  is generated, and then, the first portion  23  is exposed to light caused by the reflected light B′. That is, the first portion  23  remains by the unintended reflected light B′ corresponding to the inclination face  15 , and therefore, the reliability of the second wire  20  is decreased. 
     To be specific, in Comparative Examples 3 to 6, 9 to 11, and 14 described later in detail, the distance L2, the width W2, and the formula (1) are satisfied, so that as shown in  FIG. 8A , the distance (short distance) of the reflected light B′ reaching the first portion  23  is achieved, the amount of light at the first portion  23  is high, to be specific, the amount of light is the amount of light that allows the first portion  23  to remain in developing, or even more. Thus, the evaluation of the shape of the second wire  20  is bad. 
     Accordingly, as in the fourth embodiment, the photomask  24  is disposed so that the third portion  29  is shielded from light. That is, the second light shield portion  32  faces the third portion  29 . Thus, as shown in  FIG. 16A , in the step (4), the first portion  23  is surely shielded from light and the photoresist  25  can be exposed to light. Thereafter, as shown in  FIG. 16B , in the step (5), the metal thin film  33  corresponding to the first portion  23  can be surely exposed. Then, as shown in  FIG. 16C , in the step (6), the second wire  20  in which deformation is suppressed can be surely provided. 
     To be specific, in each of Examples 2 to 9 corresponding to the above-described Comparative Examples 3 to 6, 9 to 11, and 14, the evaluation of the shape of the second wire  20  is good. 
     As shown in  FIG. 15  and  FIG. 17A , the first portion  23  corresponding to the second linear portion  22  is disposed relatively far from the first linear portion  12 , so that as shown in  FIG. 17B  and  FIG. 17C , even when the dummy wire  21  corresponding to the first linear portion  12  is not provided, the reflected light B′ at the second portion  28  corresponding to the third linear portion  36  does not reach the first portion  23 . Thus, deformation of the second linear portion  22  does not occur, and there is no need for providing the dummy wire  21 . 
     5. Modified Example of Fourth Embodiment 
     As shown in  FIG. 15 , in the fourth embodiment, the third linear portion  36  is provided in the first conductive pattern  4 , and the dummy wire  21  that is overlapped with the third linear portion  36  is provided when projected in the thickness direction. 
     However, as shown in  FIG. 18 , a fourth linear portion  38  is provided in the second conductive pattern  6 , and the dummy wire  21  can be disposed next to the fourth linear portion  38  at the other side in the width direction when viewed from the top. 
     As shown in  FIG. 18 , the first wire  10  consists of only the first linear portion  12 . 
     When viewed from the top, the second wire  20  integrally includes the two second linear portions  22  that are relatively far from the first linear portion  12 , the fourth linear portion  38  that is closer relative to the second linear portion  22 , and a first connecting portion  39  that connects the second linear portion  22  and the fourth linear portion  38 . 
     The dummy wire  21  is short relative to the first linear portion  12  in the front-back direction. Meanwhile, when projected in the width direction, the dummy wire  21  is overlapped with the fourth linear portion  38 , to be more specific, positioned at the same position as the fourth linear portion  38 . 
     The wired circuit board  1  in the modified example is produced in the same manner as that of the wired circuit board  1  of the first embodiment, and achieves the same operations and effects as those of the first embodiment. 
     As shown in  FIG. 19 , the first wire  10  may not have the first linear portion  12  and the second connecting portion  37  (ref:  FIG. 15 ) and may consist of only the third linear portion  36 , and the second wire  20  may not have the second linear portion  22  and the first connecting portion  39  (ref:  FIG. 18 ) and may consist of only the fourth linear portion  38 . In such a case, the dummy wire  21  is parallel with the first wire  10  and the second wire  20 , and extends long in the front-back direction. The dummy wire  21  has a linear shape along the front-back direction. The dummy wire  21  is overlapped with the inclination face  15  corresponding to the ridgeline portion  13  at one side in the width direction of the first wire  10  (third linear portion  36 ) when projected in the thickness direction. 
     The wired circuit board  1  of the fourth embodiment is produced using the negative type photoresist  25 . In the modified example, though not shown, the wired circuit board  1  of the fourth embodiment can be also produced using the positive type photoresist  25 . 
     Fifth Embodiment 
     In the fifth embodiment, for the members and steps that are the same as the first to fourth embodiments, the same reference numerals are given and detailed descriptions thereof are omitted. 
     In the fifth embodiment, as shown in  FIG. 20  and  FIG. 21 , the second conductive pattern  6  includes the dummy portion  35 . 
     In the fifth embodiment, each of the first wire  10  and the second wire  20  is the same as the first wire  10  and the second wire  20  of the fourth embodiment. 
     1. Dummy Portion 
     As shown in  FIG. 20  and  FIG. 21 , in the fifth embodiment, the dummy portion  35  that continues from the second wire  20  is included. 
     The dummy portion  35  projects from the other end portion in the width direction of the second wire  20  so as to reach one end portion in the width direction of the third linear portion  36  when projected in the thickness direction. That is, the dummy portion  35  is a projection portion that projects from the second wire  20  toward the other side in the width direction. The dummy portion  35  has a generally rectangular shape or a generally trapezoidal shape when viewed from the top. The dummy portion  35  continues from the second wire  20  in the width direction. 
     The maximum length in the projection direction (width direction) of the dummy portion  35  is set suitably, for example, 3 μm or more, preferably 5 μm or more, and for example, 300 μm or less, preferably 100 μm or less. 
     2. Method for Producing a Wired Circuit Board 
     The wired circuit board  1  of the fifth embodiment is produced by the same production method as that of the third embodiment (ref:  FIG. 13A  to  FIG. 13C ). 
     The fifth embodiment also achieves the same operations and effects as those of the fourth embodiment. 
     Furthermore, as shown in  FIG. 20 , the dummy portion  35  continues from the second wire  20 , so that a simpler configuration can be achieved than the fourth embodiment (ref:  FIG. 15 ) in which the second wire  20  and the dummy wire  21  are separately provided. 
     3. Modified Example of Fifth Embodiment 
     As shown in  FIG. 20  and  FIG. 21 , in the fifth embodiment, the third linear portion  36  is provided in the first conductive pattern  4 , and the dummy portion  35  that is overlapped with the third linear portion  36  is provided when projected in the thickness direction. 
     However, as shown in  FIG. 22 , the fourth linear portion  38  is provided in the second conductive pattern  6 , and the dummy portion  35  can continue from the fourth linear portion  38  at the other side in the width direction when viewed from the top. 
     The dummy portion  35  is a projection portion that projects from the other end portion in the width direction of the fourth linear portion  38  toward the other side in the width direction. 
     As shown in  FIG. 23 , the first wire  10  may not have the first linear portion  12  and the second connecting portion  37  (ref:  FIG. 20 ) and may consist of only the third linear portion  36 , and the second wire  20  may not have the second linear portion  22  and the first connecting portion  39  (ref:  FIG. 22 ) and may consist of only the fourth linear portion  38 . In such a case, the dummy portion  35  can be formed to be parallel with the first wire  10  and the second wire  20 , and extend long and wide in the front-back direction. 
     The dummy portion  35  is overlapped with the inclination face  15  corresponding to the ridgeline portion  13  at one side in the width direction of the first wire  10  (third linear portion  36 ) when projected in the thickness direction. The dummy portion  35  is a pattern of being overlapped with one end portion in the width direction of the first wire  10  in the entire front-back direction when viewed from the top. The second conductive pattern  6  having the dummy portion  35  is a wider wiring pattern than the first conductive pattern  4 . 
     In the wired circuit board  1  of the fifth embodiment, either the negative type photoresist  25  or the positive type photoresist  25  can be used. 
     Modified Example of First to Fifth Embodiments 
     The inclination face  15  of the intermediate insulating layer  5  of the first to fifth embodiments corresponds to the ridgeline portion  13  of the first conductive pattern  4 . 
     However, for example, as shown in  FIG. 24 , the inclination face  15  does not correspond to the first conductive pattern  4 , and the insulating base layer  3  as an example of the insulating layer simply has a plurality of a thickness T 1  and a thickness T 2 , so that the insulating base layer  3  can also have the inclination face  15 . The thickness T 1  is the thickness of the insulating base layer  3  in the first flat face  14 . The thickness T 2  is the thickness of the insulating base layer  3  in the second flat face  16 . 
     The wired circuit board  1  includes the insulating base layer  3 , the first conductive pattern  4  that is provided on the insulating base layer  3 , and has the second wire  20  and the dummy wire  21 , and the insulating cover layer  7  that is provided on the insulating base layer  3  so as to cover the first conductive pattern  4 . 
     Meanwhile, the wired circuit board  1  does not include the intermediate insulating layer  5  and the first conductive pattern  4 . 
     The modified example also achieves the same operations and effects as those of the first to fifth embodiments. 
     As the wired circuit board of the present invention, the wired circuit board  1  is used. However, the wired circuit board of the present invention is not limited to this, and a suspension board with circuit including a metal supporting board  2  can be also used. In such a case, the suspension board with circuit includes the metal supporting board  2 , the insulating base layer  3 , the first conductive pattern  4 , the intermediate insulating layer  5 , the second conductive pattern  6 , and the insulating cover layer  7 . 
     The intermediate insulating layer  5  has the second flat face  16 , but does not have to have the second flat face  16  as long as at least the inclination face  15  is included. 
     The above-described first to fifth embodiments can be suitably combined. For example, the second conductive pattern  6  can also include both of the dummy wire  21  (ref:  FIG. 1 ) and the dummy portion  35  (ref:  FIG. 15 ). 
     The intermediate insulating layer  5  can also include both of the bent portion  17  (ref:  FIG. 1 ) and the inclination face  15  corresponding to the third linear portion  36 . 
     EXAMPLES 
     The present invention will hereinafter be described based on Examples and Comparative Examples below. The present invention is however not limited by the following Examples and Comparative Examples. The specific numerical values in mixing ratio (content ratio), property value, and parameter used in the following description will be replaced with upper limits (numerical values defined as “or less” or “less than”) or lower limits (numerical values defined as “or more” or “more than”) of corresponding numerical values in mixing ratio (content ratio), property value, and parameter described in the above-described “DESCRIPTION OF EMBODIMENTS”. 
     Example 1 (Example Corresponding to First Embodiment) 
     As shown in  FIG. 3A , first, the insulating base layer  3  made of polyimide having a thickness of 10 μm was prepared (step (i)). 
     As shown in  FIG. 3B , next, the first conductive pattern  4  made of copper was provided on the insulating base layer  3  (step (ii)). As shown in  FIG. 1 , the first conductive pattern  4  integrally includes the first arc portion  11  and the two first linear portions  12 . The first conductive pattern  4  had a thickness of 9 μm and the width W1 of 20 μm. The virtual circle along the first arc portion  11  had the radius R1 of 50 μm. The central angle α of the first arc portion  11  was 90 degrees. 
     As shown in  FIG. 3C , next, the intermediate insulating layer  5  made of polyimide was provided on the insulating base layer  3  so as to cover the first conductive pattern  4  (step (1)). The intermediate insulating layer  5  has the first flat face  14 , the inclination face  15 , and the second flat face  16 . The inclination face  15  has the bent portion  17 . The supplementary angle β to the angle β′ formed with the bent portion  17  and the first flat face  14  was 30 degrees. The virtual circle along the bent portion  17  had the radius R2 of 40 μm. 
     As shown in  FIG. 4D , next, the metal thin film  33  consisting of a chromium thin film having a thickness of 30 nm and a copper thin film having a thickness of 70 μm was provided on the intermediate insulating layer  5  by a sputtering method (step (2)). 
     As shown in  FIG. 4E , next, the photoresist  25  having a thickness of 20 μm was provided on the metal thin film  33  (step (3)). 
     As shown in  FIG. 4F , next, the photomask  24  was disposed so that the first portion  23  and the third portion  29  in the photoresist  25  were shielded from light (step (4)). To be specific, the photomask  24  was disposed so that the first light shield portion  31  faced the first portion  23 , and the second light shield portion  32  faced the third portion  29 . 
     As shown in the arrow of  FIG. 4F , subsequently, the photoresist  25  was exposed to light thorough the photomask  24  (step (4)). 
     As shown in  FIG. 5G , next, by developing, the first portion  23  and the third portion  29  in the photoresist  25  were removed, and the metal thin film  33  corresponding to the first portion  23  and the third portion  29  was exposed (step (5)). 
     As shown in  FIG. 5H , next, by electrolytic copper plating in which electricity is supplied from the metal thin film  33 , the second conductive pattern  6  was provided on the metal thin film  33  exposed from the photoresist  25  (step (6)). As shown  FIG. 1 , the second conductive pattern  6  includes the second wire  20 , and the dummy wire  21  in an arc shape when viewed from the top that is independent from the second wire  20 . The second conductive pattern  7  had a thickness of 9 μm. The second linear portion  22  had the width W2 of 10 μm. The dummy wire  21  had the width W3 of 20 μm. The virtual circle along the dummy wire  21  had the radius R3 of 35 μm. The central angle of the arc of the dummy wire  21  was 90 degrees. 
     As shown in  FIG. 5I , next, the photoresist  25  was removed by etching (step (iii)). 
     As shown in  FIG. 6J , next, the metal thin film  33  corresponding to the photoresist  25  was removed by peeling (step (iv)). 
     As shown in  FIG. 6K , next, the insulating cover layer  7  made of polyimide having a thickness of 5 μm was provided on the intermediate insulating layer  5  so as to cover the second conductive pattern  6  (step (v)). 
     In this manner, a suspension board with circuit  1  was produced. 
     When the obtained suspension board with circuit  1  was observed, deformation such as breakage was not observed in the second wire  20 . 
     Comparative Example 1 (Comparative Example Corresponding to Example 1) 
     The suspension board with circuit  1  was obtained in the same manner as that in Example 1, except that the dummy wire  21  was not provided in the second conductive pattern  6  ( FIG. 7 , FIG.  8 A to  FIG. 8C ). That is, in the step (4), as shown in  FIG. 8A , in the photomask  24 , the light shield portion  27  does not have the second light shield portion  32  corresponding to the third portion  29  (ref:  FIG. 4F ), and has only the first light shield portion  31  corresponding to the first portion  23 . 
     However, as shown in  FIG. 8A , in the step (4), a light shielding failure of the first portion  23  caused by generation of the reflected light B′ in the metal thin film  33  corresponding to the first portion  23  occurred; as shown in  FIG. 8B , in the step (5), the first portion  23  could not be removed; and as shown in the solid line of  FIG. 8C , at the center CP (ref:  FIG. 7 ) and near the center CP, deformation of the second wire  20  occurred. 
     Example 2 (Example Corresponding to Fourth Embodiment) 
     As shown in  FIG. 3A , first, the insulating base layer  3  made of polyimide having a thickness of 10 μm was prepared (step (i)). 
     As shown in  FIG. 3B , next, the first conductive pattern  4  made of copper was provided on the insulating base layer  3  (step (ii)). As shown in  FIG. 15 , the first conductive pattern  4  integrally includes the two first linear portions  12 , the third linear portion  36 , and the second connecting portion  37  connecting the first linear portions  12  and the third linear portion  36 . The first conductive pattern  4  had a thickness of 9 μm and the width W1 of 20 μm. 
     As shown in  FIG. 3C , next, the intermediate insulating layer  5  made of polyimide was provided on the insulating base layer  3  so as to cover the first conductive pattern  4  (step (1)). The intermediate insulating layer  5  has the first flat face  14 , the inclination face  15 , and the second flat face  16 . The angle β formed with the inclination face  15  and the first flat face  14  was 30 degrees. 
     As shown in  FIG. 4D , next, the metal thin film  33  consisting of a chromium thin film having a thickness of 30 nm and a copper thin film having a thickness of 70 μm was provided on the intermediate insulating layer  5  by a sputtering method (step (2)). 
     As shown in  FIGS. 16A and 17A , next, the photoresist  25  having a thickness of 20 μm was provided on the metal thin film  33  (step (3)). 
     Next, the photomask  24  was disposed so that the first portion  23  and the third portion  29  in the photoresist  25  were shielded from light (step (4)). To be specific, the photomask  24  was disposed so that the first light shield portion  31  faced the first portion  23 , and the second light shield portion  32  faced the third portion  29 . 
     As shown in the arrow of  FIG. 16A  and  FIG. 17A , subsequently, the photoresist  25  was exposed to light thorough the photomask  24  (step (4)). 
     As shown in  FIGS. 16B and 17B , next, by developing, the first portion  23  and the third portion  29  in the photoresist  25  were removed, and the metal thin film  33  corresponding to the first portion  23  and the third portion  29  was exposed (step (5)). 
     Next, by electrolytic copper plating in which electricity is supplied from the metal thin film  33 , the second conductive pattern  6  was provided on the metal thin film  33  exposed from the photoresist  25  (step (6)). The second conductive pattern  6  includes the second wire  20  and the dummy wire  21  that is independent from the second wire  20 . The second conductive pattern  6  had a thickness of 9 μm. The second linear portion  22  had the width W2 of 7.5 μm. The dummy wire  21  had the width W3 of 20 μm. When viewed from the top, the distance (interval) L1 between the third linear portion  36  and the second linear portion  22  in the width direction was 20 μm. The distance L2 between the inclination face  15  and the second linear portion  22  was 17.5 μm. The length (=L2−L1) obtained by subtracting the distance L1 from the distance L2 was 2.5 μm. 
     Next, as shown in  FIG. 5I , the photoresist  25  was removed by etching (step (iii)). 
     Next, as shown in  FIG. 6J , the metal thin film  33  corresponding to the photoresist  25  was removed by peeling (step (iv)). 
     As shown in  FIG. 16C  and  FIG. 17C , next, the insulating cover layer  7  made of polyimide having a thickness of 5 μm was provided on the intermediate insulating layer  5  so as to cover the second conductive pattern  6  (step (v)). 
     In this manner, the wired circuit board  1  was produced. 
     When the obtained wired circuit board  1  was observed, deformation such as breakage was not observed in the second wire  20 . 
     Comparative Example 2 (Comparative Example Corresponding to Example 2) 
     The wired circuit board  1  was obtained in the same manner as that in Example 2, except that the dummy wire  21  was not provided in the second conductive pattern  6 . 
     In the second conductive pattern  6 , deformation such as breakage was observed. 
     Example 3 to Example 9 
     The wired circuit board  1  was obtained in the same manner as that in Example 2, except that the above-described W2 and L2 (and L1) were changed according to the descriptions in Table 1 to Table 4. In Example 3 to Example 9, in the second wire  20 , deformation such as breakage was not observed. 
     Comparative Example 2 to Comparative Example 16 
     The wired circuit board  1  was obtained in the same manner as that in Example 2, except that the above-described W2 and L2 (and L1) were changed according to the descriptions in Table 1 to Table 4, and furthermore, the dummy wire  21  was not provided in the second conductive pattern  6 . 
     In the second wire  20 , evaluation of the shape such as breakage was described in Table 1 to Table 4. 
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                 Distance L2 
                   
                   
                   
                   
               
               
                   
                   
                   
                 between 
                   
                   
                   
                   
               
               
                   
                   
                   
                 Inclination Face 
                   
                 Distance L1 
                   
                   
               
               
                   
                   
                   
                 Corresponding to 
                   
                 between Third 
                   
                   
               
               
                   
                   
                   
                 Third Linear 
                   
                 Linear Portion 
                   
                   
               
               
                   
                   
                   
                 Portion and 
                   
                 and Second 
                   
                 Evaluation 
               
               
                   
                 Presence or Absence  
                 Width W2 of  
                 Second Linear 
                   
                 Linear Portion 
                   
                 of 
               
               
                   
                 of Dummy Wire 
                 Second Wire (μm) 
                 Portion (μm) 
                 Formula (1) *1 
                 (μm) 
                 Formula (2) *2 
                 Breakage 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Comp. Ex. 2 
                 — 
                 7.5 
                 22.5 
                 unsatisfactory 
                 25 
                 unsatisfactory 
                 Good 
               
               
                 Comp. Ex. 3 
                 — 
                 7.5 
                 17.5 
                 satisfactory 
                 20 
                 satisfactory 
                 Bad 
               
               
                 Ex. 2 
                 Dummy Wire 
                 7.5 
                 17.5 
                 satisfactory 
                 20 
                 satisfactory 
                 Good 
               
               
                 Comp. Ex. 4 
                 — 
                 7.5 
                 12.5 
                 satisfactory 
                 15 
                 satisfactory 
                 Bad 
               
               
                 Ex. 3 
                 Dummy Wire 
                 7.5 
                 12.5 
                 satisfactory 
                 15 
                 satisfactory 
                 Good 
               
               
                 Comp. Ex. 5 
                 — 
                 7.5 
                 7.5 
                 satisfactory 
                 10 
                 satisfactory 
                 Bad 
               
               
                 Ex. 4 
                 Dummy Wire 
                 7.5 
                 7.5 
                 satisfactory 
                 10 
                 satisfactory 
                 Good 
               
               
                 Comp. Ex. 6 
                   
                 7.5 
                 2.5 
                 satisfactory 
                 5 
                 satisfactory 
                 Bad 
               
               
                 Ex. 5 
                 Dummy Wire 
                 7.5 
                 2.5 
                 satisfactory 
                 5 
                 satisfactory 
                 Good 
               
               
                   
               
               
                 *1 L2 ≤ −2 × W + 37.5 
               
               
                 *2 L2 ≤ −2 × W + 35 
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                   
                 Distance L2 
                   
                   
                   
                   
               
               
                   
                   
                   
                 between 
                   
                   
                   
                   
               
               
                   
                   
                   
                 Inclination Face 
                   
                 Distance L1 
                   
                   
               
               
                   
                   
                   
                 Corresponding to 
                   
                 between Third 
                   
                   
               
               
                   
                 Presence or  
                   
                 Third Linear 
                   
                 Linear Portion 
                   
                   
               
               
                   
                 Absence  
                   
                 Portion and 
                   
                 and Second 
                   
                 Evaluation 
               
               
                   
                 of Dummy 
                 Width W2 of  
                 Second Linear 
                   
                 Linear Portion 
                   
                 of 
               
               
                   
                 Wire  
                 Second Wire (μm) 
                 Portion (μm) 
                 Formula (1) *1 
                 (μm) 
                 Formula (2) *2 
                 Breakage 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Comp. Ex. 7 
                 — 
                 10 
                 22.5 
                 unsatisfactory 
                 25 
                 unsatisfactory 
                 Good 
               
               
                 Comp. Ex. 8 
                 — 
                 10 
                 17.5 
                 unsatisfactory 
                 20 
                 unsatisfactory 
                 Good 
               
               
                 Comp. Ex. 9 
                 — 
                 10 
                 12.5 
                 satisfactory 
                 15 
                 satisfactory 
                 Bad 
               
               
                 Ex. 6 
                 Dummy Wire 
                 10 
                 12.5 
                 satisfactory 
                 15 
                 satisfactory 
                 Good 
               
               
                 Comp. Ex. 10 
                 — 
                 10 
                 7.5 
                 satisfactory 
                 10 
                 satisfactory 
                 Bad 
               
               
                 Ex. 7 
                 Dummy Wire 
                 10 
                 7.5 
                 satisfactory 
                 10 
                 satisfactory 
                 Good 
               
               
                 Comp. Ex. 11 
                 — 
                 10 
                 2.5 
                 satisfactory 
                 5 
                 satisfactory 
                 Bad 
               
               
                 Ex. 8 
                 Dummy Wire 
                 10 
                 2.5 
                 satisfactory 
                 5 
                 satisfactory 
                 Good 
               
               
                   
               
               
                 *1 L2 ≤ −2 × W + 37.5 
               
               
                 *2 L2 ≤ −2 × W + 35 
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                   
                   
                   
                 Distance L2 
                   
                   
                   
                   
               
               
                   
                   
                   
                 between 
                   
                   
                   
                   
               
               
                   
                   
                   
                 Inclination Face 
                   
                 Distance L1 
                   
                   
               
               
                   
                   
                   
                 Corresponding to 
                   
                 between Third 
                   
                   
               
               
                   
                   
                   
                 Third Linear 
                   
                 Linear Portion 
                   
                   
               
               
                   
                 Presence or  
                   
                 Portion and 
                   
                 and Second 
                   
                 Evaluation 
               
               
                   
                 Absence of  
                 Width W2 of  
                 Second Linear 
                   
                 Linear Portion 
                   
                 of 
               
               
                   
                 Dummy Wire 
                 Second Wire (μm) 
                 Portion (μm) 
                 Formula (1) *1 
                 (μm) 
                 Formula (2) *2 
                 Breakage 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Comp. Ex. 12 
                 — 
                 15 
                 12.5 
                 unsatisfactory 
                 15 
                 unsatisfactory 
                 Good 
               
               
                 Comp. Ex. 13 
                 — 
                 15 
                 7.5 
                 unsatisfactory 
                 10 
                 unsatisfactory 
                 Good 
               
               
                 Comp. Ex. 14 
                 — 
                 15 
                 2.5 
                 satisfactory 
                 5 
                 satisfactory 
                 Good 
               
               
                 Ex. 9 
                 Dummy Wire 
                 15 
                 2.5 
                 satisfactory 
                 5 
                 satisfactory 
                 Good 
               
               
                   
               
               
                 *1 L2 ≤ −2 × W + 37.5 
               
               
                 *2 L2 ≤ −2 × W + 35 
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                   
                   
                   
                 Distance L2 
                   
                   
                   
                   
               
               
                   
                   
                   
                 between 
                   
                   
                   
                   
               
               
                   
                   
                   
                 Inclination Face 
                   
                 Distance L1 
                   
                   
               
               
                   
                   
                   
                 Corresponding to 
                   
                 between Third 
                   
                   
               
               
                   
                   
                   
                 Third Linear 
                   
                 Linear Portion 
                   
                   
               
               
                   
                 Presence or  
                   
                 Portion and 
                   
                 and Second 
                   
                 Evaluation 
               
               
                   
                 Absence of  
                 Width W2 of  
                 Second Linear 
                   
                 Linear Portion 
                   
                 of 
               
               
                   
                 Dummy Wire 
                 Second Wire (μm) 
                 Portion (μm) 
                 Formula (1) *1 
                 (μm) 
                 Formula (2) *2 
                 Breakage 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Comp. Ex. 15 
                 — 
                 20 
                 7.5 
                 unsatisfactory 
                 10 
                 unsatisfactory 
                 Good 
               
               
                 Comp. Ex. 16 
                 — 
                 20 
                 2.5 
                 unsatisfactory 
                 5 
                 unsatisfactory 
                 Good 
               
               
                   
               
               
                 *1 L2 ≤ −2 × W + 37.5 
               
               
                 *2 L2 ≤ −2 × W + 35 
               
            
           
         
       
     
     While the illustrative embodiments of the present invention are provided in the above description, such is for illustrative purpose only and it is not to be construed as limiting the scope of the present invention. Modification and variation of the present invention that will be obvious to those skilled in the art is to be covered by the following claims.