Wiring board and manufacturing method thereof

Abstract

To facilitate identification of a front surface and a rear surface of a wiring board.SOLUTION: A wiring board which is a mirror substrate has a region where an insulating layer of a first color is formed as an outermost layer, and an identification mark where an insulating layer of a second color different from the first color is formed as an outermost layer, on either a front surface or a rear surface. In the wiring board, the other surface different from any one of the front surface and the back surface has a region where the insulating layer of the first color is formed as an outermost layer, and the identification mark is provided at an end portion of any one of the surfaces and in a region of any one of the surfaces where the component is not mounted.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a wiring board, a manufacturing method, and the like. [Background technology]

[0002] It may be difficult to distinguish between the front and back sides of a wiring board. Patent Document 1 describes an example of a wiring board in which different colors are used for the insulating layer formed as the outermost layer on one side of the wiring board and the insulating layer formed as the outermost layer on the other side of the wiring board, and the front and back sides are distinguished by the difference in color. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-01158 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of a mirror-mounted board, the front and back surfaces of the printed wiring board look similar, making it more difficult for workers to distinguish between the front and back surfaces.

[0005] An example of an object of the present disclosure is to provide a wiring board or the like that can facilitate identification of the front and back surfaces. [Means for solving the problem]

[0006] A wiring substrate according to an aspect of the present disclosure is a wiring substrate that is a mirror substrate, Either the front or back surface has a region in which an insulating layer of a first color is formed as an outermost layer, and an identification mark in which an insulating layer of a second color different from the first color is formed as an outermost layer, the other surface of the front surface and the back surface, which is different from either one of the surfaces, has a region in which the insulating layer of the first color is formed as an outermost layer; The identification mark is provided at an edge of one of the surfaces, in an area of ​​the surface where no components are mounted.

[0007] A method for manufacturing a wiring substrate according to one aspect of the present disclosure is a method for manufacturing a wiring substrate that is a mirror substrate, comprising: forming an insulating layer of a first color on the surface; forming an insulating layer of a first color on the back surface; forming an insulating layer on the surface, the insulating layer having a second color different from the first color; Equipped with the step of forming the insulating layer of the first color on the surface includes a step of exposing and developing the insulating layer of the first color so that the insulating layer of the first color is not formed in the area corresponding to the identification mark; The step of forming an insulating layer of a second color on the surface includes a step of exposing and developing the insulating layer of the second color in an area corresponding to the identification mark; The identification mark is formed at the edge of the surface, in an area of ​​the surface where no components are mounted. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to easily distinguish between the front and back surfaces of a wiring board. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1 is an explanatory diagram (part 1) showing an example of a wiring board that is a mirror mounting board. [Figure 1B] FIG. 2 is an explanatory diagram (part 2) showing an example of a wiring board that is a mirror mounting board. [Figure 2] FIG. 10 is an explanatory diagram showing an example of an identification mark formed by silk printing. [Figure 3A] 10 is an explanatory diagram showing an example in which soldering is performed on a wiring board using a solder printing jig; FIG. [Figure 3B] 10 is an explanatory diagram showing an example in which soldering is performed on a wiring board with silk printing using a solder printing jig; FIG. [Figure 4]10 is an explanatory diagram showing an example in which copper foil on the surface of a wiring board is used as an identification mark; FIG. [Figure 5] FIG. 10 is an explanatory diagram showing an example in which copper foil comes into contact with a non-insulating material. [Figure 6] 10 is an explanatory diagram showing an example in which an identification mark with a very small width is created on the edge of a substrate. FIG. [Figure 7] 10A and 10B are explanatory diagrams showing an example in which a semicircular notch is formed on the end surface of a substrate. [Figure 8A] FIG. 2 is an explanatory diagram illustrating an example of a surface of a wiring substrate. [Figure 8B] FIG. 2 is an explanatory diagram showing an example of a rear surface of a wiring board. [Figure 9A] FIG. 1 is an explanatory diagram (part 1) showing a simplified method for creating an identification mark. [Figure 9B] FIG. 2 is a simplified explanatory diagram (part 2) showing a method for creating an identification mark. [Figure 10] FIG. 10 is an explanatory diagram showing an example of a wiring board on which an identification mark is formed. [Figure 11] 10 is an explanatory diagram showing an example in which wiring boards on which identification marks are formed are arranged on a board loader; FIG. [Figure 12] 10 is an explanatory diagram showing another example in which wiring boards on which identification marks are formed are arranged on a board loader. FIG. [Figure 13A] 10A and 10B are explanatory diagrams showing a flow for forming a first color solder resist on the rear and front surfaces without creating an identification mark. [Figure 13B] FIG. 10 is an explanatory diagram showing a flow when an identification mark is created on a surface. [Figure 14] FIG. 10 is an explanatory diagram showing the flow of a solder resist forming process. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a wiring substrate and a method for manufacturing a wiring substrate according to the present disclosure will be described in detail with reference to the accompanying drawings. However, the disclosed technology is not limited to these embodiments.

[0011] A mirrored assembly board is a board that has a mirror image of a typical printed wiring board layout. It is used in manufacturing processes where components are mounted on the backside of a wiring board, or when required for a specific application. In surface mount technology (SMT) manufacturing processes, components are mounted on the top surface of the board.

[0012] It is possible to mount components on both sides of a board called a mirror mounting board. Specifically, the layout and wiring design of a PWB (Printed Wiring Board) is mirror-inverted, and components are mounted on the reverse side as well.

[0013] 1A and 1B are explanatory diagrams showing an example of a wiring board that is a mirror-mounted board. In FIGS. 1A and 1B, the entire wiring board 100 is a mirror-mounted board. For example, in FIGS. 1A and 1B, the entire wiring board 100 has an A-substrate and a B-substrate. In FIGS. 1A and 1B, the same mounting is performed on the front surface 101 of the A-substrate and the back surface 104 of the B-substrate, and the same mounting is performed on the back surface 103 of the A-substrate and the front surface 102 of the B-substrate. The A-substrate and the B-substrate are vertically symmetrical with respect to a vertical symmetry axis. Note that when the A-substrate and the B-substrate are cut at the center of the vertical symmetry axis, they become the same product.

[0014] The ink that forms the insulating film that covers the surface of the wiring board is called solder resist. In reality, the wiring board is covered with copper foil, and that copper foil is then covered with solder resist. The area where solder resist is not applied is also called solder resist runout.

[0015] Before describing specific embodiments, the inventors will first explain the consideration of providing an identification mark on either the front or back surface of a wiring board in order to distinguish between the front and back surfaces.

[0016] At the beginning of the process of mounting components on printed wiring boards, the printed wiring boards are lined up in a board loader. A board loader is a device that automatically supplies printed wiring boards to machines on a production line. Workers may manually line up printed wiring boards on the board loader. When printed wiring boards are mirror-mounted boards, the front and back surfaces look similar, making it difficult for workers to distinguish between them. In such cases, the inventors considered providing an identification mark on one of the surfaces. For example, the identification mark should be displayed in a position that allows workers to distinguish between the front and back surfaces of the printed wiring boards even when the printed wiring boards are lined up in the board loader. For example, when printed wiring boards are lined up in the board loader with their front surfaces facing up, we considered providing an identification mark on the front edge of the printed wiring board, the edge facing in the direction of removal from the board loader. For example, the identification mark should be partially formed within 5 mm of the edge opposite the direction in which the wiring board is inserted into the board loader. Furthermore, it is desirable for the identification mark to have contrast with the solder resist portion, which is another insulating layer. Even if a printed wiring board is placed in the board loader with its back side facing up when it should be placed with its front side facing up, the worker can easily realize that he or she has mistakenly placed the board with its back side facing up if he or she cannot check the identification mark on the printed wiring board.

[0017] There are several ways to realize the identification mark depending on the PWB design specifications, including forming the identification mark by silk screen printing or exposing the copper foil.

[0018] First, we looked at an example where an identification mark is applied to a printed wiring board by silk screen printing. Silk screen printing is abbreviated to "silk printing." Silk printing on printed wiring boards is used to print identification marks such as letters and symbols on the wiring board.

[0019] FIG. 2 is an explanatory diagram showing an example of an identification mark formed by silk printing. In FIG. 2, the entire wiring board 200 is a mirror wiring board. The wiring board 200 in FIG. 2 is wiring board 100 shown in FIGS. 1A and 1B, with a throwaway board 213 further provided. The throwaway board 213 is a board that is provided around the periphery of the portion of the actual wiring board that will become the product by using a V-cut or perforations. In FIG. 2, an identification mark 214 is printed by silk printing in the area of ​​the throwaway board 213 on the surface of wiring board 200.

[0020] For example, the identification mark 214 is provided within 5 mm from the end opposite to the insertion direction d in which the wiring board 200 is inserted into the board loader.

[0021] If silk printing is used, the thickness of the indicia 214 may affect the soldering process of the component.

[0022] 3A is an explanatory diagram showing an example of soldering using a solder printing jig on wiring board 200. In Fig. 3A, wiring board 200 has original board 217 covered with copper foil 216. Furthermore, wiring board 200 has green solder resist 215 formed as the outermost insulating layer.

[0023] As shown in Fig. 3A, components may be mounted by solder on this wiring board 200 using a solder printing jig 20. As shown in Fig. 3A, the solder printing jig 20 is parallel to the surface of the wiring board 200, and the solder is pressed evenly.

[0024] 3B is an explanatory diagram showing an example of soldering using a solder printing jig on a wiring board 200 with silk printing. When mounting components with solder, the silk-printed identification mark 214 has thickness, so there are areas where the solder printing jig 20 does not adhere to the wiring board 200. This can result in uneven solder application and an uneven amount of solder. This can result in a deterioration in product quality.

[0025] In this way, if the identification mark 214 is created by silk printing, there is a risk that the thickness will increase on the surface of the wiring board 200. Since it is necessary to suppress the thickness from the surface of the wiring board 200, it is expected that it will be difficult to use silk printing.

[0026] Next, the inventors considered using the copper foil on the surface of the wiring board as an identification mark.

[0027] FIG. 4 is an explanatory diagram showing an example in which copper foil on the surface of a wiring board is used as an identification mark. The inventors did not use silk printing, but instead created an area in part of waste board 313 of wiring board 300 where no green solder resist was formed. This area is shown as resist escape area 316 in FIG. 4. The inventors then considered exposing copper foil 315 on the surface of wiring board 300 in resist escape area 316, thereby using copper foil 315 as an identification mark. This creates a contrast between the green solder resist and copper foil 315. Therefore, copper foil 315 serves as an identification mark.

[0028] FIG. 5 is an explanatory diagram showing an example where copper foil comes into contact with a non-insulating material. There are cases where it is not possible to use a disposable board. For this reason, the inventors considered creating the identification mark shown in FIG. 4 inside the product. In such cases, as shown in FIG. 5, the wiring board 400 has a resist-relief area 416 where no green solder resist is formed, similar to FIG. 4. The exposed signal wiring 17 causes a short circuit when the copper foil 415 comes into contact with a non-insulating material. For this reason, from a safety standpoint, it is difficult to use an identification mark using copper foil 415 inside the product.

[0029] For this reason, the identification mark using copper foil can be used when a board that supports the wiring board is attached during product manufacturing, called a throwaway board, as shown in Figure 4.

[0030] However, there are requirements for the design of wiring boards that do not allow silk printing and do not require the use of throwaway boards. For this reason, the inventors have considered creating an identification mark inside a board that is not a throwaway board.

[0031] Fig. 6 is an explanatory diagram showing an example in which an extremely small identification mark is created on the edge of a substrate. In Fig. 6, a resist relief portion 518 is formed as an identification mark with a width of about 0.5 mm in the copper foil prohibited area on the edge of the wiring substrate 500 so that the copper foil inside the wiring substrate 500 is not exposed.

[0032] However, because it is at the end of wiring board 500, it is difficult to distinguish between light and dark even though the width is reduced. This makes it difficult for workers to find the identification mark, and therefore, even though an identification mark is provided, it becomes difficult to identify it.

[0033] FIG. 7 is an explanatory diagram showing an example in which a semicircular notch is created on the edge surface of a substrate. Next, the inventors considered adding a semicircular notch 19 (groove) with a radius of about 1 millimeter to the edge of wiring substrate 600, as shown in FIG. 7. This allows workers to distinguish between the front and back surfaces of wiring substrate 600 by checking notch 19. However, this results in differences in the external shape of the product substrate, such as products with and without notches. Furthermore, there are cases in which adding a notch to wiring substrate 600 is not possible due to structural design considerations.

[0034] As described above, the inventors have considered various methods. When an effective marking cannot be ensured, it takes time for an operator to distinguish the marking by visual inspection alone. Therefore, as will be described using the embodiments, the inventors have discovered a wiring board in which an identification mark is formed on one surface of the wiring board using an insulating film of a different color from the insulating film of the outermost layer.

[0035] (Embodiment) Fig. 8A is an explanatory diagram showing an example of the front surface of a wiring substrate, and Fig. 8B is an explanatory diagram showing an example of the back surface of a wiring substrate.

[0036] The wiring board 1 shown in Figures 8A and 8B is a mirror mounting board. The entire wiring board 1 has an A-substrate and a B-substrate. As explained in Figures 1A and 1B, in Figures 8A and 8B as well, the same mounting is performed on the front surface 11 of the A-substrate and the back surface 14 of the B-substrate, and the same mounting is performed on the back surface 13 of the A-substrate and the front surface 12 of the B-substrate. The A-substrate and the B-substrate are vertically symmetrical when bent about the vertical symmetry axis.

[0037] In this embodiment, a wiring board 1 having two substrates, an A substrate and a B substrate, is used as an example of a mirror-mounted substrate. For example, the identification marks 10 may be provided on a total of four mirror-mounted substrates, i.e., two A substrates and two B substrates, or the identification marks 10 may be provided on a total of six wiring boards, i.e., two A substrates, two B substrates, and two C substrates. In this way, a mirror-mounted substrate is a substrate in which multiple substrates are integrated together and the front and back surfaces have the same component arrangement. Furthermore, a mirror-mounted substrate refers to a substrate design that allows components to be mounted on both surfaces without rearranging the production line. In this way, the wiring board 1 on which the identification marks 10 are provided is not limited to the examples shown in FIGS. 8A and 8B .

[0038] 8A and 8B, a first-color insulating layer is formed as the outermost layer on the front and back surfaces of the A-substrate and the B-substrate. The insulating layer is sometimes called a solder resist. On the front surface 12 of the B-substrate, there is an area where the first-color solder resist 5 is not formed, in a part of the area where components are not arranged.

[0039] 9A and 9B are explanatory diagrams illustrating a simplified method for creating an identification mark. FIGS. 9A and 9B show a cross section AA-AA' of FIG. 8A. For example, in FIG. 9A, a copper foil is covered on a substrate. Then, a first-color solder resist 5 is covered on the copper foil. At this time, in FIG. 9A, a resist relief area 6 is present in a portion of the cross section AA-AA'. As shown in FIG. 9B, a second-color solder resist 7 is formed in the resist relief area 6. This second-color solder resist serves as the identification mark. As shown in FIG. 9B, a second-color solder resist is formed with the same thickness as the first-color solder resist 5. In this way, the second-color solder resist 7 is also formed as the outermost layer, just like the first-color solder resist 5. That is, as shown in FIG. 9A, the second-color solder resist 7 and the first-color solder resist 5 are formed on approximately the same plane. Therefore, the identification mark has no thickness, which can prevent any adverse effects on the component soldering process.

[0040] FIG. 10 is an explanatory diagram showing an example of a wiring board on which an identification mark is formed. The wiring board 1 is, for example, a mirror wiring board. Either the front or back surface of the wiring board 1 has an area where an insulating layer of a first color is formed as the outermost layer, and an identification mark 10 where an insulating layer of a second color different from the first color is formed as the outermost layer. Either the front or back surface and the other surface have an area where an insulating layer of the first color is formed as the outermost layer. The identification mark 10 is provided at the edge of either surface, in an area where no components are mounted.

[0041] 10, wiring board 1 has substrate A and substrate B. Surface 12 of substrate B is provided with identification mark 10, on which a solder resist of a second color is formed. It is desirable that the first color and the second color have a contrast that allows a worker to distinguish between light and dark.

[0042] For example, the first color may be green, which is a common color for solder resist. White may be used as a second color that is easily distinguishable from green. The combination of the first and second colors is not particularly limited as long as it is distinguishable by the worker. For example, the first color may be black and the second color may be white. For example, the first color may be black and the second color may be green. For example, the first color may be black and the second color may be yellow.

[0043] White solder resist, yellow solder resist, and the like have a high reflectance to visible light, making them easy to identify by visual inspection. In this way, a light-colored solder resist with a high reflectance to visible light may be used as the identification mark 10. That is, to make it easy to identify by visual inspection, the second color of the identification mark 10 may be a light color and the first color may be a dark color. However, the first color may be a light color and the second color may be a dark color. Designers can use a solder resist of an appropriate color, taking into consideration factors such as soldering reliability, ease of visual inspection, and device characteristics.

[0044] Furthermore, for example, when the wiring board 1 is a mirror mounting board, it is not possible to display by silk printing, it is not possible to add a throwaway board, and signal wiring is arranged up to the edge of the wiring board, but even in this case, it is possible to create the light and dark identification mark 10. Note that although the example has been given in which the wiring board 1 is a mirror wiring board, the identification mark 10 may be provided on boards other than mirror wiring boards.

[0045] In FIG. 10 , the identification mark 10 is partially formed within 5 mm of the edge opposite the insertion direction d of the printed wiring board into the board loader. For example, the reason why the identification mark 10 is located within 5 mm of the edge of the wiring board 1 is that it is located in a position where a worker can see the identification mark 10 when the wiring board is lined up in the board loader. If the identification mark 10 were located more than 5 mm inside the edge of the wiring board 1, the identification mark 10 would be hidden by the overlapping wiring boards 1 in the board loader, which could make the worker unable to see the identification mark 10. Thus, the area within 5 mm is an example of the edge portion of the wiring board 1, and the position where the identification mark 10 is located may be determined appropriately depending on the size of the wiring board 1 and the board loader.

[0046] In FIG. 10 , the size of the identification mark 10 in the insertion direction d is represented by x1, and the size of the identification mark 10 in the direction perpendicular to the insertion direction d is represented by y1. x1 is preferably, for example, approximately 3 to 5 mm. In particular, x1 is preferably approximately 5 mm. y1 is preferably approximately 10 to 20 mm. In particular, y1 is preferably approximately 20 mm. For example, if an identification mark is provided by silk printing or the like, the size of the identification mark 10 is preferably 5 mm × 20 mm or more. However, the area on the wiring board 1 where no components are mounted is narrow. Therefore, if the identification mark 10 is rectangular, for example, x1 is preferably approximately 5 mm and y1 is preferably approximately 20 mm, because this makes the identification mark 10 easy for workers to see. Generally, the width that can be used for resist formation is 0.3 mm or more. The size of the identification mark 10 may be large enough to be easily distinguishable by workers and can be changed as appropriate depending on the position of the components mounted on the wiring board 1. In addition, although the sides of the identification mark 10 are approximately parallel to the inserting direction d in FIG. 10, this is not particularly limited.

[0047] In FIG. 10 , the identification mark 10 is, for example, rectangular in shape. For example, a linear shape such as a rectangle makes it easier to design an exposure mask and facilitates exposure. In particular, a rectangular shape such as a rectangle or a quadrilateral is preferable for the identification mark 10. For example, the task of arranging the wiring boards 1 on the board loader is a manual task, and the task of distinguishing between the front and back sides of the wiring boards 1 is a visual task. Therefore, a rectangular shape is easier to understand when the contrast between the identification mark 10 and the first color solder resist 5 is rectangular. However, the shape of the identification mark 10 is not particularly limited to a circle, triangle, or the like. For example, in the rectangular identification mark 10 shown in FIG. 10 , the side in the insertion direction d into the board loader is shorter than the side approximately perpendicular to the insertion direction d.

[0048] Even if the design specifications of the wiring board require that silk printing not be used, the wiring board 1 allows the identification mark 10 to be displayed on the wiring board, allowing the front and back surfaces to be easily distinguished from each other. Furthermore, the wiring board 1 allows the identification mark 10 to be formed with the same thickness as the original outermost insulating film. The original outermost insulating film is, for example, the first-color solder resist 5 in FIGS. 9A and 10 . In other words, the original outermost insulating film and the identification mark 10 are formed on approximately the same plane as shown in FIG. 9A . Therefore, even if the identification mark 10 is displayed on the wiring board 1, the impact on the soldering process, such as connecting components to the wiring board 1, can be suppressed. Furthermore, even if the design requirements require that disposable boards not be used, the wiring board 1 allows the identification mark 10 to be formed inside the board.

[0049] FIG. 11 is an explanatory diagram showing an example in which wiring boards on which identification marks are formed are arranged on a board loader. In FIG. 11, wiring board 1 is shown simply, with parts not used in the explanation omitted. As described above, at the beginning of the process of mounting components on wiring board 1, wiring boards 1 are arranged on board loader 15. Board loader 15 is a device that automatically supplies wiring boards to machines on a production line. In some cases, a worker arranges wiring boards on board loader 15 manually.

[0050] As shown in FIG. 11, it is preferable that the identification mark 10 of the wiring board 1 be provided in a position that is visible to the worker even after the wiring boards 1 have been arranged on the board loader 15.

[0051] 11, five wiring boards, 1-1 to 1-5, are arranged on board loader 15. Identification marks 10-1 to 10-5 are formed on the surfaces of wiring boards 1-1 to 1-5, respectively. For example, when wiring boards 1 are arranged on board loader 15 with the surface facing up, the worker can see identification marks 10 of each wiring board 1.

[0052] FIG. 12 is an explanatory diagram showing another example in which wiring boards 1 each having an identification mark 10 formed thereon are arranged in a board loader 15. As with FIG. 11, the wiring boards 1 in FIG. 12 are simply shown, with portions not relevant to the explanation omitted. For example, in FIG. 12, the identification mark 10-4 is not visible on the fourth wiring board 1-4 from the top. This allows the worker to realize that the fourth wiring board 1-4 has been mistakenly placed in the board loader 15 with its back side facing up.

[0053] Providing the identification mark 10 on the wiring board 1 makes it easier to distinguish between the front and back surfaces of the wiring board 1. As mentioned above, when the wiring board 1 is a mirror-mounted board, the front and back surfaces look similar, making it difficult for workers to distinguish between the front and back surfaces. For this reason, the identification mark 10 is particularly useful for mirror-mounted boards. Furthermore, having the identification mark 10 in a position that is visible when the board is placed in the board loader 15 makes work more efficient.

[0054] 13A is an explanatory diagram showing a flow for forming solder resist of a first color on the rear and front surfaces without forming the identification mark 10. Here, the first color is explained using green as an example.

[0055] For example, in a method for manufacturing a wiring board, a step of forming a green solder resist on the front surface is carried out (step S11). Next, for example, in a method for manufacturing a wiring board, a step of forming a green solder resist on the back surface is carried out (step S12). As a result, solder resist is formed as the outermost layer on both surfaces.

[0056] FIG. 13B is an explanatory diagram showing a flow when forming an identification mark 10 on the surface. Here, an example will be described in which the identification mark 10 is formed on the surface of the wiring board 1. An example will be described in which the first color is green and the second color is white. For example, in the manufacturing method of the wiring board 1, a step of forming a green solder resist 5 on the surface is carried out (step S21). Next, for example, in the manufacturing method of the wiring board 1, a step of forming a green solder resist 5 on the back surface is carried out (step S22).

[0057] Then, for example, in the method for manufacturing the wiring board 1, a step of forming a white solder resist 7 on the surface is carried out (step S23). This completes the description of the method for manufacturing the wiring board 1.

[0058] As shown in FIG. 13B, after green solder resist 5 is formed on both sides, white solder resist 7 is formed on the surface. As a result, wiring board 1 having identification mark 10 formed thereon as shown in FIG. 10 is obtained. In this manner, in the method for manufacturing wiring board 1, identification mark 10 can be formed by adding a step of forming solder resist to the step shown in FIG. 13A. Furthermore, in the method for manufacturing wiring board 1, the thickness of green solder resist 5 on the surface of wiring board 1 and the thickness of white solder resist 7 for identification mark 10 are formed to be approximately the same.

[0059] The process order of forming a green solder resist 5 on the front surface, then forming a green solder resist 5 on the back surface, and then forming a white solder resist 7 on the front surface is given as an example because it is expected to be efficient for current board manufacturers in terms of work setup. The order of the processes shown in FIG. 13B is not particularly limited, and the order of the processes may be changed as appropriate to improve the efficiency of the board manufacturer. For example, a green solder resist 5 may be formed on the back surface, a green solder resist 5 may be formed on the front surface, and a white solder resist 7 may be formed on the front surface. For example, a white solder resist 7 may be formed on the front surface, a green solder resist 5 may be formed on the front surface, and a green solder resist 5 may be formed on the back surface.

[0060] 14 is an explanatory diagram showing the flow of the solder resist forming process. For example, the solder resist forming process, which is each step shown in FIG. 13A and FIG. 13B, will be described in detail.

[0061] Specifically, the solder resist forming process includes four steps: an application step (step S31) of applying the solder resist, an exposure step (step S32) of exposing the solder resist, a development step (step S33) of developing the solder resist, and a peeling step (step S34) of peeling the solder resist.

[0062] In step S31, a liquid resist is sprayed onto the wiring board in a coating process.

[0063] In the exposure process in step S32 and the development process in step S33, a mask film shaped like an area where the resist is not to be formed is used to expose and develop the area where the resist is to be formed.

[0064] In the stripping step in step S34, unnecessary resist that has not been exposed or developed is washed away.

[0065] Here, when the identification mark 10 is formed on the surface of the wiring board 1, the process of forming a first-color insulating layer on the surface includes a process of exposing and developing the first-color insulating layer (solder resist 5) so that the first-color insulating layer is not formed in the area corresponding to the identification mark 10. The process of forming a second-color insulating layer (solder resist 7) ​​on the surface includes a process of exposing and developing the second-color insulating layer (solder resist 7) ​​in the area corresponding to the identification mark 10. That is, the mask film for the first-color solder resist 5 is shaped so that the first-color solder resist 5 is not formed in the area where the identification mark 10 is formed. The mask film for the white solder resist 7 is shaped so that the second-color solder resist 7 is formed in the area where the identification mark 10 is formed, but is not formed in the area other than the identification mark 10. This prevents the two different colors of solder resist from being overcoated. Therefore, the two colors of solder resist can be applied separately without increasing the thickness on the surface of the wiring board.

[0066] In the area where the components are arranged, wiring, pads, via holes, etc. are exposed from each insulating layer, but the manufacturing method for these may be performed using existing technology, so detailed description will be omitted.

[0067] The above describes an example in which the identification mark 10 is formed on the surface of the wiring board 1, particularly on the surface 12 of the B substrate. For example, the identification mark 10 may be formed on the surface 11 of the A substrate of the wiring board 1. Furthermore, in a mirror-mounted substrate, the front and back surfaces look the same, so the space in which the identification mark 10 can be formed is also the same on the front and back surfaces. For example, the identification mark 10 may be formed on the back surface 13 of the A substrate or the back surface 14 of the B substrate of the wiring board 1. Furthermore, the wiring board 1 may be a substrate other than a mirror substrate. In the case of a wiring board 1 other than a mirror-mounted substrate, it may be determined appropriately whether the identification mark 10 is formed on the front or back surface of the wiring board 1.

[0068] An example of a method for manufacturing a wiring board 1 in which an identification mark 10 is formed on the back surface of the wiring board 1 will be described. For example, in the method for manufacturing the wiring board 1, a step of forming a first-color solder resist 5 on the back surface is carried out. Next, for example, in the method for manufacturing the wiring board 1, a step of forming the first-color solder resist 5 on the front surface is carried out. Then, for example, in the method for manufacturing the wiring board 1, a step of forming a white solder resist 7 on the back surface is carried out. When the identification mark 10 is formed on the front surface of the wiring board 1, the step of forming a first-color insulating layer on the back surface includes a step of exposing and developing the solder resist 5 so that the first-color insulating layer (solder resist 5) is not formed in the area corresponding to the identification mark 10. Then, the step of forming a second-color insulating layer (solder resist 7) ​​on the back surface includes a step of exposing and developing the solder resist 5 so that the second-color insulating layer (solder resist 7) ​​is formed in the area corresponding to the identification mark 10. As with the example formed on the front surface, the mask film for the first-color solder resist, which is the mask film for the back surface, is shaped so that the first-color solder resist 5 is not formed in the area where the identification mark 10 is formed. The mask film for the second color solder resist 7 is shaped so that the second color solder resist 7 is formed in the area where the identification mark 10 is to be formed, and so that the second color solder resist 7 is not formed in the area other than the identification mark 10. This prevents the solder resists of two different colors from being applied on top of each other.

[0069] Also, for example, the method for manufacturing wiring board 1 may include a step of forming solder resist 5 of a first color on the front surface. Next, for example, the method for manufacturing wiring board 1 may include a step of forming solder resist 5 of the first color on the back surface. Then, for example, the method for manufacturing wiring board 1 may include a step of forming solder resist 7 of a second color on the back surface.

[0070] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above embodiments. The configuration and details of the present disclosure may include embodiments to which various modifications that would be apparent to those skilled in the art are applied within the scope of the present disclosure. The present disclosure may include embodiments in which the features described herein are appropriately combined or substituted as necessary. For example, features described using a particular embodiment may also be applied to other embodiments to the extent that no contradiction occurs. For example, although multiple operations are described in sequence in the form of a flowchart, the order of description does not limit the order in which the multiple operations are performed. Therefore, when implementing the embodiments, the order of the multiple operations may be changed as long as the content is not affected.

[0071] Some or all of the above-described embodiments can be described as follows: However, some or all of the above-described embodiments are not limited to the following.

[0072] (Appendix 1) A wiring substrate that is a mirror substrate, Either the front or back surface has a region in which an insulating layer of a first color is formed as an outermost layer, and an identification mark in which an insulating layer of a second color different from the first color is formed as an outermost layer, the other surface of the front surface and the back surface, which is different from either one of the surfaces, has a region in which the insulating layer of the first color is formed as an outermost layer; The identification mark is provided at an edge portion of one of the surfaces, in an area of ​​the one of the surfaces where no components are mounted. Wiring board.

[0073] (Appendix 2) The identification mark is provided at a position that is visible when the substrates are aligned with the substrate loader. 2. The wiring substrate of claim 1.

[0074] (Appendix 3) The end portion of any one of the surfaces is the end portion opposite to the direction in which the substrate is inserted into the substrate loader. 3. The wiring board according to claim 1 or 2.

[0075] (Appendix 4) The identification mark is provided partially within 5 mm from the edge of either of the surfaces. 4. The wiring board according to claim 1.

[0076] (Appendix 5) The shape of the identification mark is rectangular. 5. The wiring board according to any one of appendices 1 to 4.

[0077] (Appendix 6) The second color is lighter than the first color. 6. The wiring board according to any one of appendices 1 to 5.

[0078] (Appendix 7) the first color is green; the second color is white; 7. The wiring board according to claim 6.

[0079] (Appendix 8) the any one of the faces is the surface, The other surface is the back surface. 8. The wiring board according to any one of appendices 1 to 7.

[0080] (Appendix 9) A method for manufacturing a wiring substrate that is a mirror substrate, comprising: forming an insulating layer of a first color on the surface; forming an insulating layer of a first color on the back surface; forming an insulating layer on the surface, the insulating layer having a second color different from the first color; Equipped with The step of forming the insulating layer of the first color on the surface includes a step of exposing and developing the insulating layer of the first color so that the insulating layer of the first color is not formed in an area corresponding to the identification mark; The step of forming an insulating layer of a second color on the surface includes a step of exposing and developing the insulating layer of the second color in an area corresponding to the identification mark; the identification mark is formed at an edge of the surface, in an area of ​​the surface where no components are mounted; A method for manufacturing a wiring board.

[0081] (Appendix 10) The identification mark is provided at a position that is visible when the substrates are aligned with the substrate loader. The manufacturing method described in Appendix 9.

[0082] (Appendix 11) The end portion of any one of the surfaces is the end portion opposite to the direction in which the substrate is inserted into the substrate loader. The method of manufacturing according to claim 9 or 10.

[0083] (Appendix 12) The identification mark is provided partially within 5 mm from the edge of either of the surfaces. A method for producing a compound according to any one of claims 9 to 11.

[0084] (Appendix 13) The shape of the identification mark is rectangular. A method for producing a compound according to any one of claims 9 to 12.

[0085] (Appendix 14) The second color is lighter than the first color. A method for producing a compound according to any one of claims 9 to 13.

[0086] (Appendix 15) the first color is green; the second color is white; The manufacturing method described in Appendix 14.

[0087] (Appendix 16) the any one of the faces is the surface, The other surface is the back surface. A method for producing a compound according to any one of claims 9 to 15. [Explanation of symbols]

[0088] 1, 1-1, 1-2, 1-3, 1-4, 1-5 Wiring board 5 First color solder resist 6 Resist escape area 7 Second color solder resist 10, 10-1, 10-2, 10-3, 10-4 Identification mark 11 A board surface 12 B Surface of the board 13 Back side of A board 14 Back side of B board 15 Board Loader 17 Exposure 20 Printing jig 100 wiring board 101 A board surface 102 B substrate surface 103 A Backside of the board 104 B Backside of board 200 wiring board 213 Disposable PCB 214 Identification mark 215 Green solder resist 216 Copper foil 217 Substrate 300 Wiring board 313 Disposable PCB 315 Copper foil 316 locations 400 wiring board 415 Copper foil 416 locations 500 wiring board 518 locations 600 Wiring board AA-AA' cross section d Feeding direction

Claims

1. A wiring substrate that is a mirror substrate, Either the front or back surface has a region in which an insulating layer of a first color is formed as an outermost layer, and an identification mark in which an insulating layer of a second color different from the first color is formed as an outermost layer, the other surface of the front surface and the back surface, which is different from either one of the surfaces, has a region in which the insulating layer of the first color is formed as an outermost layer; The identification mark is provided at an edge portion of one of the surfaces, in an area of ​​the one of the surfaces where no components are mounted. Wiring board.

2. The identification mark is provided at a position that is visible when the substrates are aligned with the substrate loader. The wiring board according to claim 1 .

3. The end portion of any one of the surfaces is the end portion opposite to the direction in which the substrate is inserted into the substrate loader. The wiring board according to claim 1 .

4. A part of the identification mark is provided in an area within 5 mm from an edge of any one of the surfaces. The wiring board according to claim 1 .

5. The shape of the identification mark is rectangular. The wiring board according to claim 1 .

6. The second color is lighter than the first color. The wiring board according to claim 1 .

7. the first color is green; The second color is white. The wiring board according to claim 6 .

8. the any one of the faces is the surface, The other surface is the back surface. The wiring board according to claim 1 .

9. A method for manufacturing a wiring substrate that is a mirror substrate, comprising: forming an insulating layer of a first color on the surface; forming an insulating layer of a first color on the back surface; forming an insulating layer on the surface, the insulating layer having a second color different from the first color; Equipped with The step of forming the insulating layer of the first color on the surface includes a step of exposing and developing the insulating layer of the first color so that the insulating layer of the first color is not formed in an area corresponding to the identification mark, The step of forming an insulating layer of a second color on the surface includes a step of exposing and developing the insulating layer of the second color in an area corresponding to the identification mark, the identification mark is formed at an edge of the surface, in an area of ​​the surface where no components are mounted; A method for manufacturing a wiring board.

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