Print circuit board and design method of print circuit board

Abstract

To provide a print circuit board capable of performing evaluation of a stable tracking resistance.SOLUTION: Each of print circuit boards (100A, 100B, 100C, 100D, and 100E) of the present disclosure comprises: a base material (10); and a first wiring pattern (20) and a second wiring pattern (30) that are arranged onto the base material. The first wiring pattern includes a first end (20a). The second wiring pattern includes a second end (30a). The first end and the second end are opposite to each other in a first direction (DR1) while having a gap therebetween. The first wiring pattern is extended along the first direction from the first end. The second wiring pattern is extended along the first direction that is opposite to the first wiring pattern from the second end. A distance (DIS) between the first end and the second end is changed along a second direction (DR2) orthogonal to the first direction, and becomes a minimal length only in one position in the second direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a printed wiring board and a method for designing a printed wiring board. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 2017-15411 (Patent Document 1) describes a printed wiring board. The printed wiring board described in Patent Document 1 has an insulating substrate, a first wiring pattern, and a second wiring pattern. The first wiring pattern and the second wiring pattern are disposed on the insulating substrate. The first wiring pattern has a first end. The first wiring pattern has a second end opposed to the first end with a gap therebetween. The first wiring pattern extends from the first end along a first direction. The second wiring pattern extends from the second end along the first direction opposite to the first wiring pattern. Each of the first end and the second end is formed of a side extending along the second direction. The second direction is a direction perpendicular to the first direction.

[0003] The tracking resistance is evaluated using the printed wiring board described in Patent Document 1. First, an electrolyte is dropped between the first end and the second end. The dropped electrolyte is in contact with both the first end and the second end. Second, a voltage is applied between the first wiring pattern and the second wiring pattern to evaluate the tracking resistance of the printed wiring board described in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-15411 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the printed wiring board described in Patent Document 1, the first end and the second end are each formed by a side extending along the second direction, so the distance between the first end and the second end in the first direction does not change depending on the position in the second direction. As a result, in the printed wiring board described in Patent Document 1, the position where tracking occurs is not constant.

[0006] The present disclosure has been made in consideration of the problems of the conventional techniques as described above. More specifically, the present disclosure provides a printed wiring board that enables stable evaluation of tracking resistance. [Means for solving the problem]

[0007] The printed wiring board of the present disclosure includes a substrate, and a first wiring pattern and a second wiring pattern disposed on the substrate. The first wiring pattern has a first end. The second wiring pattern has a second end. The first end and the second end face each other with a gap in between in a first direction. The first wiring pattern extends from the first end along the first direction. The second wiring pattern extends from the second end along the first direction on a side opposite to the first wiring pattern. The distance between the first end and the second end varies along a second direction perpendicular to the first direction, and is the shortest distance only at one position in the second direction. Effect of the Invention

[0008] According to the printed wiring board of the present disclosure, it is possible to stably evaluate the tracking resistance. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view of a printed wiring board 100A. [Diagram 2] FIG. 2 is a schematic front view of the evaluation device 200. [Diagram 3] FIG. 2 is a schematic plan view of an evaluation device 200. [Figure 4] FIG. 2 is a schematic perspective view of an evaluation device 200. [Diagram 5]FIG. 1 is a first schematic diagram illustrating an evaluation of tracking resistance using a printed wiring board 100A. [Figure 6] FIG. 2 is a second schematic diagram illustrating evaluation of tracking resistance using the printed wiring board 100A. [Figure 7] FIG. 11 is a third schematic diagram illustrating evaluation of tracking resistance using the printed wiring board 100A. [Figure 8] FIG. 2 is a plan view of a printed wiring board 300. [Figure 9] FIG. 2 is a perspective view of a printed wiring board 300. [Figure 10] FIG. 1 is a first schematic diagram illustrating an evaluation of tracking resistance using a printed wiring board 300. [Figure 11] 2 is a second schematic diagram illustrating evaluation of tracking resistance using the printed wiring board 300. FIG. [Figure 12] FIG. 2 is a plan view of a printed wiring board 100B. [Figure 13] FIG. 2 is a plan view of a printed wiring board 100C. [Figure 14] FIG. 11 is a plan view of a printed wiring board 100C according to a modified example. [Figure 15] FIG. 1 is a plan view of a printed wiring board 100D. [Figure 16] FIG. 2 is a plan view of a printed wiring board 100E. [Figure 17] 1A to 1C are schematic diagrams showing a method for designing a printed wiring board 100A. [Figure 18] 1 is a schematic diagram illustrating a case where a printed wiring board 100A is designed using a line 81 that does not have a width. [Figure 19] 1A and 1B are explanatory diagrams for explaining effects of the printed wiring board 100A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and redundant description will not be repeated.

[0011] Embodiment 1 A printed wiring board according to a first embodiment (hereinafter referred to as "printed wiring board 100A") will be described.

[0012] (Configuration of printed wiring board 100A) The configuration of printed wiring board 100A will be described below.

[0013] Fig. 1 is a plan view of a printed wiring board 100A. As shown in Fig. 1, the printed wiring board 100A has a substrate 10, a wiring pattern 20, and a wiring pattern 30. The printed wiring board 100A is a printed wiring board used for evaluating tracking resistance.

[0014] The substrate 10 has a first surface 10a and a second surface 10b (see FIG. 2). The first surface 10a and the second surface 10b are end surfaces in the thickness direction of the substrate 10. The second surface 10b is the surface opposite to the first surface 10a. A view seen from the first surface 10a side along the normal direction of the first surface 10a is called a plan view. The substrate 10 is made of an insulating material.

[0015] The wiring pattern 20 is disposed on the substrate 10. More specifically, the wiring pattern 20 is disposed on the first surface 10a. The wiring pattern 20 has an end 20a. In a plan view, the wiring pattern 20 extends from the end 20a along a first direction DR1. In a plan view, the wiring pattern 20 extends linearly. The wiring pattern 20 is made of a conductive material. A specific example of the material of the wiring pattern 20 is copper.

[0016] The wiring pattern 30 is disposed on the substrate 10. More specifically, the wiring pattern 30 is disposed on the first surface 10a. The wiring pattern 30 has an end 30a. The end 30a faces the end 20a with a gap in between in the first direction DR1. The wiring pattern 30 extends from the end 30a along the first direction DR1 toward the opposite side to the wiring pattern 20 (end 20a) in a plan view. The wiring pattern 30 extends linearly in a plan view. The wiring pattern 30 is made of a conductive material. A specific example of the material of the wiring pattern 30 is copper.

[0017] The end 20a is composed of a side 20aa and a side 20ab. The side 20aa extends linearly in a plan view. The side 20aa is inclined with respect to the first direction DR1. The side 20ab extends linearly in a plan view. The side 20ab is inclined with respect to the first direction DR1 on the side opposite to the side 20aa. The sides 20aa and 20ab are connected to each other at a vertex 20ac. The vertex 20ac may be rounded. The angle between the sides 20aa and 20ab may be less than 180°.

[0018] The end 30a is composed of a side 30aa and a side 30ab. The side 30aa extends linearly in a plan view. The side 30aa is inclined with respect to the first direction DR1. The side 30ab extends linearly in a plan view. The side 30ab is inclined with respect to the first direction DR1 on the side opposite to the side 30aa. The sides 30aa and 30ab are connected to each other at a vertex 30ac. The vertex 30ac may be rounded. The angle between the sides 30aa and 30ab may be less than 180°.

[0019] The vertex 30ac is preferably opposed to the vertex 20ac with a gap therebetween in the first direction DR1. That is, the position of the vertex 20ac in the second direction DR2 is preferably consistent with the position of the vertex 30ac in the second direction DR2. However, the position of the vertex 20ac in the second direction DR2 may be shifted from the position of the vertex 30ac in the second direction DR2. The second direction DR2 is a direction perpendicular to the first direction DR1 in a plan view.

[0020] The distance between the end 20a and the end 30a is a distance DIS. The distance DIS changes along the second direction DR2. The distance DIS is the shortest distance only at one position in the second direction DR2, more specifically, between the vertex 20ac and the vertex 30ac. This shortest distance is, for example, 1 mm or more and 4 mm or less.

[0021] (Evaluation of tracking resistance using printed wiring board 100A) A method for evaluating the tracking resistance using printed wiring board 100A will be described below.

[0022] FIG. 2 is a schematic front view of the evaluation device 200. FIG. 3 is a schematic plan view of the evaluation device 200. FIG. 4 is a schematic perspective view of the evaluation device 200. In FIGS. 3 and 4, only the electrodes 40 and 41 are shown as an excerpt from the configuration of the evaluation device 200. As shown in FIGS. 2 to 4, the evaluation device 200 includes the electrodes 40 and 41, a DC power source 50, an ammeter 51, a voltmeter 52, a dripping device 60, and a control device 70.

[0023] The electrode 40 is in contact with one of the wiring pattern 20 and the wiring pattern 30, and the electrode 41 is in contact with the other of the wiring pattern 20 and the wiring pattern 30. In the example shown in Figures 2 to 4, the electrode 40 and the electrode 41 are in contact with the wiring pattern 20 and the wiring pattern 30, respectively.

[0024] The DC power supply 50 is electrically connected to the electrodes 40 and 41. As a result, a DC voltage is applied between the electrodes 40 and 41. The voltage output by the DC power supply 50, i.e., the voltage applied between the electrodes 40 and 41, is, for example, about 10 V. The current output by the DC power supply 50 is, for example, about 10 mA. The ammeter 51 is electrically connected in series to the DC power supply 50. The ammeter 51 measures the current flowing between the wiring pattern 20 and the wiring pattern 30. The voltmeter 52 is electrically connected in parallel to the DC power supply 50. The voltmeter 52 measures the voltage between the electrodes 40 and 41.

[0025] The dripping device 60 has an electrolyte tank 61, a nozzle 62, and a valve 63. The electrolyte tank 61 stores an electrolyte EL. The electrolyte EL is, for example, an aqueous solution of ammonium chloride. However, the electrolyte EL is not limited to this. The nozzle 62 is connected to the electrolyte tank 61 at one end. That is, the electrolyte EL flows through the nozzle 62. The other end of the nozzle 62 is a drip port, which is located above the first surface 10a between the end 20a and the end 30a. The valve 63 is attached to the nozzle 62. By opening and closing the valve 63, the electrolyte EL is dripped from the drip port of the nozzle 62 onto the first surface 10a between the end 20a and the end 30a.

[0026] The control device 70 has a voltage control unit 71, a timer unit 72, and a drip interval control unit 73. The voltage control unit 71 outputs a control signal to the DC power supply 50. This adjusts the voltage output by the DC power supply 50. The drip interval control unit 73 outputs a control signal to the drip device 60 (more specifically, the valve 63) based on the current measured by the ammeter 51, the voltage measured by the voltmeter 52, and time information output from the timer unit 72. This causes the electrolyte EL to be dripped onto the first surface 10a between the ends 20a and 30a. The amount of the electrolyte EL to be dripped is selected so that the space between the ends 20a and 30a is filled with the electrolyte EL. The amount of the electrolyte EL to be dripped is, for example, 0.001 g or more and 0.1 g or less.

[0027] The evaluation of tracking resistance using the printed wiring board 100A is performed by applying a voltage between the electrodes 40 and 41 in a state where the space between the ends 20a and 30a is filled with the electrolyte EL. The electrical resistance value between the electrodes 40 and 41 is measured in a state where a current is passed between the electrodes 40 and 41. This electrical resistance value is calculated by dividing the value of the voltage applied between the electrodes 40 and 41 by the value of the current flowing between the electrodes 40 and 41.

[0028] When a current is applied between the electrodes 40 and 41, the wiring patterns 20 and 30 are corroded and dissolved. Fig. 5 is a first schematic diagram for explaining evaluation of tracking resistance using the printed wiring board 100A. Fig. 6 is a second schematic diagram for explaining evaluation of tracking resistance using the printed wiring board 100A. Fig. 7 is a third schematic diagram for explaining evaluation of tracking resistance using the printed wiring board 100A.

[0029] 5 to 7, as the corrosion and dissolution of the wiring patterns 20 and 30 progresses, the corrosion and dissolution products accumulate, and a bridge connection portion 10c is formed on the first surface 10a between the ends 20a and 30a so as to connect the ends 20a and 30a. The smaller the distance DIS, the more electric field concentration occurs, so the bridge connection portion 10c is likely to be formed at a location where the distance DIS is the shortest.

[0030] When the bridge connection portion 10c is formed, the electrical resistance value between the electrodes 40 and 41 decreases. Therefore, when the electrical resistance value between the electrodes 40 and 41 becomes equal to or less than a predetermined threshold value (bridge determination resistance value), it can be determined that tracking has occurred between the wiring pattern 20 and the wiring pattern 30.

[0031] (Effects of printed wiring board 100A) The effects of printed wiring board 100A will be described below in comparison with a printed wiring board according to a comparative example (hereinafter referred to as "printed wiring board 300").

[0032] FIG. 8 is a plan view of the printed wiring board 300. FIG. 9 is a perspective view of the printed wiring board 300. Electrode 40 and electrode 41 are also shown in FIGS. 8 and 9. As shown in FIGS. 8 and 9, the printed wiring board 300 has a substrate 10, a wiring pattern 20, and a wiring pattern 30. In this respect, the configuration of the printed wiring board 300 is common to the configuration of the printed wiring board 100A. In the printed wiring board 300, each of the end 20a and the end 30a is formed by a side that extends linearly along the second direction DR2. In this respect, the configuration of the printed wiring board 300 is different from the configuration of the printed wiring board 100A.

[0033] The tracking resistance using printed wiring board 300 is also evaluated by passing a current between wiring pattern 20 and wiring pattern 30 using electrodes 40 and 41, and monitoring the electrical resistance value between wiring pattern 20 and wiring pattern 30.

[0034] FIG. 10 is a first schematic diagram for explaining evaluation of tracking resistance using the printed wiring board 300. FIG. 11 is a second schematic diagram for explaining evaluation of tracking resistance using the printed wiring board 300. In the printed wiring board 300, the end 20a and the end 30a are each formed by sides extending linearly along the second direction DR2, so the distance DIS does not change depending on the position in the second direction DR2. As a result, in the printed wiring board 300, as shown in FIG. 10 and FIG. 11, the bridge connection portion 10c is not formed in a constant manner due to the spreading of the electrolyte solution EL, and the tracking resistance cannot be stably evaluated.

[0035] On the other hand, in the printed wiring board 100A, the distance DIS is the shortest only at one position in the second direction DR2, more specifically, between the vertices 20ac and 30ac. Therefore, in the printed wiring board 100A, the bridge connection portion 10c is always formed at one position in the second direction DR2 (specifically, between the vertices 20ac and 30ac), and it is possible to stably evaluate the tracking resistance.

[0036] Embodiment 2 A printed wiring board according to the second embodiment (hereinafter referred to as "printed wiring board 100B") will be described. Here, differences from printed wiring board 100A will be mainly described, and overlapping descriptions will not be repeated.

[0037] (Configuration of printed wiring board 100B) The configuration of printed wiring board 100B will be described below.

[0038] FIG. 12 is a plan view of the printed wiring board 100B. As shown in FIG. 12, the printed wiring board 100B has a substrate 10, a wiring pattern 20, and a wiring pattern 30. In this respect, the configuration of the printed wiring board 100B is common to that of the printed wiring board 100A. In the printed wiring board 100B, the end 30a is composed of a side 30ad. The side 30ad extends linearly in a plan view. The side 30ad is, for example, along the second direction DR2. Therefore, the distance DIS is the shortest only between the vertex 20ac and one position on the side 30ad (more specifically, the intersection of the side 30ad and a perpendicular line from the vertex 20ac to the side 30ad). In these respects, the configuration of the printed wiring board 100B is different from that of the printed wiring board 100A.

[0039] (Effects of printed wiring board 100B) The effects of printed wiring board 100B will be described below.

[0040] As with printed wiring board 100A, in printed wiring board 100B, distance DIS is the shortest at only one position in the second direction DR2, so that the position at which bridge connection portion 10c is formed is constant, enabling stable evaluation of tracking resistance.

[0041] Embodiment 3 A printed wiring board according to a third embodiment (hereinafter referred to as "printed wiring board 100C") will be described. Here, differences from printed wiring board 100A will be mainly described, and overlapping descriptions will not be repeated.

[0042] (Configuration of printed wiring board 100C) The configuration of printed wiring board 100C will be described below.

[0043] Fig. 13 is a plan view of printed wiring board 100C. As shown in Fig. 13, printed wiring board 100C has a substrate 10, a wiring pattern 20, and a wiring pattern 30. In this regard, the configuration of printed wiring board 100C is common to the configuration of printed wiring board 100A.

[0044] In the printed wiring board 100C, the end 20a has an arc 20ad, and the end 30a has an arc 30ae. The radius of the arc 20ad is, for example, equal to 0.5 times the width of the wiring pattern 20 in the second direction DR2. The radius of the arc 30ae is, for example, equal to 0.5 times the width of the wiring pattern 30 in the second direction DR2. For example, the end point (first end point) of the arc 20ad in the first direction DR1 faces the end point (second end point) of the arc 30ae in the first direction DR1 with a gap in between in the first direction DR1. Therefore, the distance DIS is the shortest distance only at one position in the second direction DR2 (more specifically, between the first end point and the second end point). In these respects, the configuration of the printed wiring board 100C is different from that of the printed wiring board 100A.

[0045] <Modification> Fig. 14 is a plan view of a printed wiring board 100C according to a modified example. As shown in Fig. 14, the radius of the arc 20ad may be less than 0.5 times the width of the wiring pattern 20 in the second direction DR2, and the radius of the arc 30ae may be less than 0.5 times the width of the wiring pattern 30 in the second direction DR2. That is, in the printed wiring board 100C, the end 20a may not be composed of only the arc 20ad, and the end 30a may not be composed of only the arc 30ae.

[0046] (Effects of printed wiring board 100C) The effects of printed wiring board 100C will be described below.

[0047] As with printed wiring board 100A, in printed wiring board 100C, distance DIS is shortest only at one position in second direction DR2, so that the position at which bridge connection portion 10c is formed is constant, enabling stable evaluation of tracking resistance.

[0048] Embodiment 4 A printed wiring board according to a fourth embodiment (hereinafter referred to as "printed wiring board 100D") will be described. Here, differences from printed wiring board 100C will be mainly described, and overlapping descriptions will not be repeated.

[0049] (Configuration of printed wiring board 100D) The configuration of printed wiring board 100D will be described below.

[0050] Fig. 15 is a plan view of printed wiring board 100D. As shown in Fig. 15, printed wiring board 100D has a substrate 10, a wiring pattern 20, and a wiring pattern 30. In printed wiring board 100D, end 20a has a circular arc 20ad. In these respects, the configuration of printed wiring board 100D is common to the configuration of printed wiring board 100C.

[0051] In printed wiring board 100D, end 30a is formed by side 30ad. Therefore, distance DIS is the shortest distance only between the first end point of arc 20ad and one position on side 30ad (more specifically, the intersection point between side 30ad and a perpendicular line drawn from the first end point of arc 20ad to side 30ad). In these respects, the configuration of printed wiring board 100D is different from that of printed wiring board 100C.

[0052] (Effects of printed wiring board 100D) The effects of printed wiring board 100D will be described below.

[0053] As with printed wiring board 100C, in printed wiring board 100D, distance DIS is shortest only at one position in the second direction DR2, so that the position at which bridge connection portion 10c is formed is constant, enabling stable evaluation of tracking resistance.

[0054] Embodiment 5. A printed wiring board according to the fifth embodiment (hereinafter referred to as "printed wiring board 100E") will be described. Here, differences from printed wiring board 100C will be mainly described, and overlapping descriptions will not be repeated.

[0055] (Configuration of printed wiring board 100E) The configuration of printed wiring board 100E will be described below.

[0056] Fig. 16 is a plan view of printed wiring board 100E. As shown in Fig. 16, printed wiring board 100E has a substrate 10, a wiring pattern 20, and a wiring pattern 30. In printed wiring board 100E, end 20a has a circular arc 20ad. In these respects, the configuration of printed wiring board 100E is common to the configuration of printed wiring board 100C.

[0057] In printed wiring board 100E, end 30a is composed of side 30aa and side 30ab. Therefore, distance DIS is the shortest only at one position in second direction DR2 (more specifically, between the first end point of arc 20ad and vertex 30ac). In these respects, it is different from the configuration of printed wiring board 100C.

[0058] (Effects of Printed Wiring Board 100E) The effects of printed wiring board 100E will be described below.

[0059] As with printed wiring board 100C, in printed wiring board 100E, distance DIS is shortest only at one position in second direction DR2, so that the position at which bridge connection portion 10c is formed is constant, enabling stable evaluation of tracking resistance.

[0060] Embodiment 6 A method for designing a printed wiring board according to the sixth embodiment will be described. Here, a method for designing printed wiring board 100A will be described as an example. Note that the method for designing a printed wiring board according to the sixth embodiment can also be applied to the design of printed wiring boards 100B to 100E.

[0061] (Design method for printed wiring board 100A) A method for designing printed wiring board 100A will be described below.

[0062] The printed wiring board 100A is designed using CAD (Computer Aided Design). Fig. 17 is a schematic diagram showing a method for designing the printed wiring board 100A. As shown in Fig. 17, in the design data (CAD data) of the printed wiring board 100A, the areas that will become the wiring patterns 20 and 30 are represented as lines 80 with width, i.e., data including apertures.

[0063] (Effect of the design method of the printed wiring board 100A) A method for designing printed wiring board 100A will be described below.

[0064] Fig. 18 is a schematic diagram of a case where a printed wiring board 100A is designed using a line 81 with no width. As shown in Fig. 18, in the design data of the printed wiring board 100A, the outline of the area that will become the wiring pattern 20 and the wiring pattern 30 can be represented by a line 81 with no width. In this case, the design is easy because it is only necessary to trace the outline of the area that will become the wiring pattern 20 and the wiring pattern 30 at the design stage.

[0065] When the outline of the area that will become the wiring pattern 20 and the wiring pattern 30 is represented by a line 81 with no width, the design data cannot be used for manufacturing as it is, so the line 81 needs to be converted to a line 82 with width at the manufacturing stage. FIG. 19 is an explanatory diagram for explaining the effect of the printed wiring board 100A. When performing the above conversion, how to set the line 82 is left to the manufacturer. Therefore, the width of the line 82 may be narrow or wide. Then, as shown in FIG. 19, a shift occurs in the position of the vertex 20ac (vertex 30ac) when the width of the line 82 is set wide and when it is set narrow, and the shortest distance of the distance DIS changes. As a result, it becomes difficult to stably evaluate the tracking resistance.

[0066] On the other hand, if the areas that will become wiring patterns 20 and 30 in the design data are represented by lines 80 with width at the design stage, there is no need to convert the lines 80 when the design data is used for manufacturing. Therefore, according to the design method for printed wiring board 100A, it is possible to design printed wiring board 100A that allows stable evaluation of tracking resistance.

[0067] (Additional Note) Aspects of the present disclosure are summarized in the appendix.

[0068] <Appendix 1> A substrate; a first wiring pattern and a second wiring pattern disposed on the base material; the first wiring pattern has a first end, the second wiring pattern has a second end, the first end and the second end face each other with a gap in between in a first direction, the first wiring pattern extends from the first end along the first direction, the second wiring pattern extends from the second end to an opposite side to the first wiring pattern along the first direction, A printed wiring board, wherein the distance between the first end and the second end varies along a second direction perpendicular to the first direction, and is the shortest distance only at one position in the second direction.

[0069] <Appendix 2> The first end is composed of a first side and a second side extending linearly, the first side is inclined with respect to the first direction, the second side is inclined with respect to the first direction on a side opposite to the first side, the first side and the second side are connected to each other at a first vertex, The second end is composed of a third side and a fourth side extending linearly, the third side is inclined with respect to the first direction, the fourth side is inclined with respect to the first direction on a side opposite to the third side, the third side and the fourth side are connected to each other at a second vertex, 2. The printed wiring board of claim 1, wherein the distance between the first vertex and the second vertex is the shortest distance.

[0070] <Appendix 3> The first end is composed of a first side and a second side extending linearly, the first side is inclined with respect to the first direction, the second side is inclined with respect to the first direction on a side opposite to the first side, the first side and the second side are connected to each other at a first vertex, The second end is formed by a fifth side extending linearly, 2. The printed wiring board of claim 1, wherein the distance between the first vertex and the fifth side is the shortest distance.

[0071] <Appendix 4> the first end has a first arc; the second end has a second arc; 2. The printed wiring board of claim 1, wherein the distance between the first arc and the second arc is the shortest distance.

[0072] <Appendix 5> the first end has a first arc; The second end is formed by a fifth side extending linearly, 2. The printed wiring board of claim 1, wherein the distance between the first arc and the fifth side is the shortest distance.

[0073] <Appendix 6> the first end has a first arc; The second end is composed of a third side and a fourth side extending linearly, the third side is inclined with respect to the first direction, the fourth side is inclined with respect to the first direction on a side opposite to the third side, the third side and the fourth side are connected to each other at a second vertex, 2. The printed wiring board of claim 1, wherein the distance between the first arc and the second vertex is the shortest distance.

[0074] <Appendix 7> A method for designing a printed wiring board according to any one of Supplementary Note 1 to Supplementary Note 6, A method for designing a printed wiring board, wherein the external shapes of the first wiring pattern and the second wiring pattern are designed as data including an aperture.

[0075] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of this application is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0076] 10 substrate, 10a first surface, 10b second surface, 10c bridge connection portion, 20 wiring pattern, 20a, 30a end, 20aa, 20ab side, 20ac vertex, 20ad arc, 30 wiring pattern, 30aa, 30ab side, 30ac vertex, 30ad side, 30ae arc, 40, 41 electrode, 50 DC power source, 51 ammeter, 52 voltmeter, 60 dripping device, 61 electrolyte tank, 62 nozzle, 63 valve, 70 control device, 71 voltage control portion, 72 timer portion, 73 drip interval control portion, 80, 81, 82 line, 100A, 100B, 100C, 100D, 100E, 300 printed wiring board, 200 evaluation device, DIS distance, DR1 first direction, DR2 Second direction, EL electrolyte.

Claims

1. A substrate; a first wiring pattern and a second wiring pattern disposed on the base material; the first wiring pattern has a first end; the second wiring pattern has a second end; the first end and the second end face each other with a gap in between in a first direction, the first wiring pattern extends from the first end along the first direction, the second wiring pattern extends from the second end to a side opposite to the first wiring pattern along the first direction, A printed wiring board, wherein the distance between the first end and the second end varies along a second direction perpendicular to the first direction, and is the shortest distance only at one position in the second direction.

2. The first end is composed of a first side and a second side extending linearly, The first side is inclined with respect to the first direction, the second side is inclined with respect to the first direction on a side opposite to the first side, the first side and the second side are connected to each other at a first vertex, The second end is composed of a third side and a fourth side extending linearly, The third side is inclined with respect to the first direction, the fourth side is inclined with respect to the first direction on a side opposite to the third side, the third side and the fourth side are connected to each other at a second vertex, The printed wiring board according to claim 1 , wherein the distance between the first vertex and the second vertex is the shortest distance.

3. The first end is composed of a first side and a second side extending linearly, The first side is inclined with respect to the first direction, the second side is inclined with respect to the first direction on a side opposite to the first side, the first side and the second side are connected to each other at a first vertex, The second end is formed by a fifth side extending linearly, The printed wiring board according to claim 1 , wherein the distance between the first vertex and the fifth side is the shortest distance.

4. the first end has a first arc; the second end has a second arc; The printed wiring board according to claim 1 , wherein the distance between the first arc and the second arc is the shortest distance.

5. the first end has a first arc; The second end is formed by a fifth side extending linearly, The printed wiring board according to claim 1 , wherein the distance between the first arc and the fifth side is the shortest distance.

6. the first end has a first arc; The second end is composed of a third side and a fourth side extending linearly, The third side is inclined with respect to the first direction, the fourth side is inclined with respect to the first direction on a side opposite to the third side, the third side and the fourth side are connected to each other at a second vertex, The printed wiring board according to claim 1 , wherein the distance between the first arc and the second vertex is the shortest distance.

7. A method for designing a printed wiring board according to any one of claims 1 to 6, comprising the steps of: A method for designing a printed wiring board, wherein the external shapes of the first wiring pattern and the second wiring pattern are designed as data including an aperture.

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