Method for manufacturing wiring circuit board

Abstract

This method for manufacturing a wiring circuit board comprises: a step for forming an insulating layer atop an elongated metal support substrate by means of a roll-to-roll process; and a step for forming a plating resist layer, which includes a photosensitive material, atop the insulating layer by means of the roll-to-roll process. In addition, this method for manufacturing a wiring circuit board comprises: a step for exposing the plating resist layer using a prescribed pattern by means of the roll-to-roll process; a step for developing the plating resist layer exposed using the prescribed pattern by means of the roll-to-roll process, and thereby forming, in the plating resist layer, an opening having the prescribed pattern or an opposite pattern to the prescribed pattern; and a step for forming a conductor layer inside the opening by means of the roll-to-roll process. The step for forming the plating resist layer includes applying a photosensitive resist liquid on the insulating layer and then performing a heat treatment on the liquid film of the applied resist liquid.

Description

Method for manufacturing a printed circuit board

[0001] The present invention relates to a method for manufacturing a printed circuit board.

[0002] Conventionally, roll-to-roll methods have been widely used in manufacturing wired circuit boards such as flexible wired circuit boards. In roll-to-roll methods, for example, a roll around which a long support substrate is wound is prepared. The support substrate is unwound from the prepared roll. The unwound support substrate is subjected to a predetermined treatment, and the treated support substrate is wound into a roll (see, for example, Patent Document 1).

[0003] In the method for manufacturing a suspension board with circuit described in Patent Document 1, the predetermined process involves forming a base insulating layer, a chromium thin film, and a copper thin film in this order on a support substrate. Furthermore, a plating resist is formed on the copper thin film using a dry film resist. The plating resist has openings that are the reverse of the predetermined pattern. Furthermore, a conductor layer of a predetermined pattern is formed as wiring on the copper thin film exposed in the areas where the plating resist is not formed. Thereafter, the plating resist and the copper thin film in the areas where the conductor layer is not formed are removed.

[0004] Roll-to-roll manufacturing makes it possible to carry out part or all of the above series of processes continuously, thereby improving the production efficiency of wired circuit boards and reducing production costs.

[0005] Japanese Patent Application Laid-Open No. 2005-135981

[0006] In recent years, as the applications of flexible printed circuit boards have become more diverse, there has been a demand for finer conductor patterns. However, the manufacturing method described in Patent Document 1 has limitations on how fine the conductor patterns can be made.

[0007] An object of the present invention is to provide a method for manufacturing a wired circuit board that can manufacture a wired circuit board having a fine conductor pattern with high production efficiency.

[0008] As described above, a dry film resist is used to form a plating resist on the support substrate and insulating layer. The dry film resist has a structure in which a film made of a photosensitive material and a protective film are laminated, and can be easily applied to the support substrate and insulating layer. The dry film resist applied to the support substrate and insulating layer is exposed and developed. This forms a plating resist with openings in a predetermined pattern.

[0009] To achieve finer conductor patterns, it is necessary to further refine the opening patterns in the plating resist. To further refine the opening patterns, it is desirable to reduce the thickness of the plating resist, i.e., to thin the dry film resist. However, when considering the strength required for roll-to-roll applications, there is a limit to how thin the dry film resist can be. The present inventors have focused on the above points and devised the following invention.

[0010] (1) A method for manufacturing a wired circuit board according to one aspect of the present invention includes the steps of: preparing a laminate in which an insulating layer is formed on a long metal supporting substrate; forming a plating resist layer containing a photosensitive material on the insulating layer by roll-to-roll; exposing the plating resist layer to light in a predetermined pattern by roll-to-roll; developing the plating resist layer exposed to light in the predetermined pattern by roll-to-roll, thereby forming openings in the plating resist layer in the predetermined pattern or a pattern opposite to the predetermined pattern; and forming a conductor layer in the openings by roll-to-roll, wherein the step of forming the plating resist layer includes applying a photosensitive plating resist liquid onto the insulating layer and subjecting the applied plating resist liquid to heat treatment.

[0011] In the method for manufacturing the wired circuit board, the steps of forming a plating resist layer, exposing the plating resist layer to a predetermined pattern, forming an opening in the plating resist layer, and forming a conductor layer are each performed by roll-to-roll, thereby enabling the wired circuit board to be manufactured with high production efficiency.

[0012] The plating resist layer is formed by applying a plating resist solution onto an insulating layer and then subjecting the applied plating resist solution to a heat treatment. Here, the thickness of the plating resist solution film formed on the insulating layer can be reduced by adjusting the amount of plating resist solution supplied to the insulating layer. In this case, the thickness of the plating resist layer can be made sufficiently smaller than that of a plating resist layer formed using a dry film resist. A thinner plating resist layer allows for the formation of openings in a finer pattern in the plating resist layer.

[0013] As a result, it becomes possible to manufacture printed circuit boards having fine conductor patterns with high productivity.

[0014] (2) The step of exposing the plating resist layer to a predetermined pattern may include contact exposure in which a mask corresponding to the predetermined pattern and the plating resist layer are brought into contact with each other, and exposure light is irradiated onto the plating resist layer through the mask.

[0015] In this case, the mask and the plating resist layer come into contact with each other, thereby fixing the positional relationship between the mask and the plating resist layer. Also, since no gap (space) is formed between the mask and the plating resist layer, the spread of exposure light is suppressed. As a result, exposure of fine patterns can be performed with higher accuracy.

[0016] (3) The contact exposure may include applying a pressure equal to or greater than a predetermined pressure between the mask and the plating resist layer while the mask and the plating resist layer are in contact with each other, thereby enabling exposure of finer patterns with even higher precision.

[0017] (4) The metal supporting board may be made of stainless steel. A metal supporting board made of stainless steel has higher rigidity than, for example, a metal supporting board made of copper. This reduces the occurrence of undulations in a portion of the metal supporting board located between the unwinding roll and the winding roll in a roll-to-roll process. Therefore, the shape of the metal supporting board is likely to be maintained flat during transportation. In this case, the thickness of the plating resist layer formed on the metal supporting board is less likely to vary, enabling exposure of a fine pattern with high precision. Furthermore, deformation of the opening pattern formed in the plating resist layer due to deformation of the metal supporting board is reduced.

[0018] Furthermore, stainless steel has a relatively low thermal conductivity as a metal material. For example, a metal supporting board made of stainless steel has a lower thermal conductivity than a metal supporting board made of copper. As a result, when the plating resist solution is subjected to a heat treatment, the metal supporting board prevents the temperature of the plating resist solution from rising sharply. This allows the solvent components of the plating resist solution to be appropriately removed.

[0019] (5) The plating resist solution may be made of a positive photosensitive resin, and the method for manufacturing a wiring circuit board may further include, after the step of forming the conductor layer, a step of exposing the entire plating resist layer by roll-to-roll, and a step of developing the plating resist layer whose entire surface has been exposed by roll-to-roll, thereby removing the plating resist layer on the insulating layer.

[0020] In this case, the entire plating resist layer formed adjacent to the conductor layer is dissolved in the developer. Therefore, the unnecessary plating resist layer can be easily removed from the metal supporting board after the conductor layer is formed. This prevents part of the plating resist layer from remaining as foreign matter on the produced wired circuit board.

[0021] (6) After the step of forming the conductor layer, in the step of exposing the entire plating resist layer, the exposure dose of the plating resist layer is 5 mJ / cm ２In this case, by supplying a developer to the exposed plating resist layer, the plating resist layer on the insulating layer is smoothly dissolved in the developer. As a result, even if the plating resist layer is present between a plurality of fine wirings made of the conductor layer, the plating resist layer can be smoothly removed in a short time without damaging the conductor layer.

[0022] (7) The insulating layer may be made of photosensitive polyimide. In this case, forming the insulating layer using photolithography technology allows for a thinner insulating layer. Furthermore, the insulating layer can be easily formed into a desired pattern. Furthermore, when the insulating layer is formed of photosensitive polyimide, the surface of the insulating layer can be made mirror-finished without the need for mechanical or chemical processing. When the surface of the insulating layer is mirror-finished, scattering of the exposure light incident on the insulating layer during exposure of the plating resist layer is suppressed. This makes it possible to form openings in an even finer pattern in the plating resist layer.

[0023] (8) The method may further include a step of forming a seed layer on the insulating layer by roll-to-roll processing after the step of preparing the laminate and before the step of forming the plating resist layer, wherein in the step of forming the plating resist layer, the plating resist layer is formed on the insulating layer via the seed layer, and the step of forming the conductor layer may include forming the conductor layer by electrolytic plating on the seed layer exposed in the opening. In this case, the conductor layer can be formed by electrolytic plating.

[0024] According to the present invention, it becomes possible to manufacture a printed circuit board having a fine conductor pattern with high production efficiency.

[0025] FIG. 1 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 2 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 3 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 4 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 5 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 6 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 7 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 8 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 9 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 10 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 11 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 12 is a manufacturing process diagram illustrating a method for manufacturing a wired circuit board according to an embodiment of the present invention. FIG. 13 is a schematic diagram illustrating an example of the configuration of a roll-to-roll apparatus used in the method for manufacturing a wired circuit board. Fig. 14 is a schematic diagram showing another example of the configuration of a roll-to-roll apparatus used in the method for manufacturing a wired circuit board. Fig. 15 is a schematic diagram showing another example of the configuration of a roll-to-roll apparatus used in the method for manufacturing a wired circuit board.

[0026] A method for manufacturing a wired circuit board according to an embodiment of the present invention will now be described with reference to the drawings. As an example of the method for manufacturing a wired circuit board, a method for manufacturing a flexible wired circuit board applicable to semiconductor devices and the like will be described. In the following description, the flexible wired circuit board will be abbreviated as the wired circuit board.

[0027] 1 to 12 are manufacturing process diagrams illustrating a manufacturing method for a wired circuit board according to one embodiment of the present invention. First, a roll (hereinafter referred to as a pay-out roll) around which a long metal supporting board 1 is wound is prepared, and the metal supporting board 1 is paid out from the prepared pay-out roll. The metal supporting board 1 paid out from the pay-out roll is taken up on another roll (hereinafter referred to as a take-up roll). FIG. 1 shows a part of the metal supporting board 1 paid out from the pay-out roll. The metal supporting board 1 according to this embodiment is a supporting board made of stainless steel.

[0028] The thickness of the metal supporting board 1 is preferably 10 μm or more and 100 μm or less, and is 20 μm in this embodiment. When the thickness of the metal supporting board 1 is 10 μm or more, the rigidity required for producing a wired circuit board by roll-to-roll is ensured in the metal supporting board 1. When the thickness of the metal supporting board 1 is 100 μm or less, the flexibility required for producing a wired circuit board by roll-to-roll is ensured.

[0029] 2 , an insulating layer 2 made of photosensitive polyimide is formed in a predetermined region on the upper surface of the unwound metal supporting board 1. The thickness of the insulating layer 2 is 1 μm or more and 30 μm or less. Note that the insulating layer 2 may be formed so as to cover the entire upper surface of the metal supporting board 1.

[0030] Next, as shown in FIG. 3 , a seed layer 3 is formed so as to cover the upper surface of the insulating layer 2, the side surfaces of the insulating layer 2, and portions of the upper surface of the metal supporting board 1 where the insulating layer 2 is not formed. The seed layer 3 has a configuration in which a copper thin film is further laminated on an underlayer formed of two or more thin films selected from a chromium thin film, a nickel thin film, a titanium thin film, and a chromium-nickel alloy thin film. The seed layer 3 may also have a configuration in which one thin film selected from a chromium thin film, a nickel thin film, a titanium thin film, and a chromium-nickel alloy thin film is used as an underlayer, and a copper thin film is laminated on the underlayer. Each thin film constituting the seed layer 3 is formed by, for example, sputtering or electroless plating. The thickness of the seed layer 3 is 0.01 μm or more and 1 μm or less.

[0031] 4, a resist liquid 4p is applied onto the seed layer 3. As a result, a liquid film 4 of the resist liquid 4p is formed on the seed layer 3. The application of the resist liquid 4p onto the seed layer 3 is performed by a resist application device 30. The resist application device 30 includes a coating nozzle 31 that extends, for example, in a direction perpendicular to the transport direction of the metal supporting board 1 (hereinafter referred to as the transverse direction).

[0032] The coating nozzle 31 is provided at a position above the metal supporting board 1 transported between the pay-out roll and the take-up roll, and has a slit-shaped liquid discharge port 31s extending in the transverse direction. The coating nozzle 31 discharges the resist liquid 4p in a curtain shape from the slit-shaped liquid discharge port 31s toward the transported metal supporting board 1. In this embodiment, a positive photosensitive resin is used as the resist liquid 4p. More specifically, a positive photosensitive phenolic resin or a positive acrylic resin is used as the resist liquid 4p. The amount of the resist liquid 4p supplied onto the metal supporting board 1 is adjusted so that the liquid film 4 is 1 μm or more and 15 μm or less.

[0033] Next, the liquid film 4 of the resist liquid 4p is subjected to a heat treatment. The resist liquid 4p contains a solvent component. The heat treatment removes the solvent component contained in the liquid film 4, and a hardened resist layer 5 is formed as shown in FIG. 5. The thickness of the resist layer 5 is 1 μm or more and 5 μm or less.

[0034] Next, the resist layer 5 is exposed to light in a predetermined pattern. The exposure of the resist layer 5 is performed by a first exposure device 50 shown in FIG. 6. The first exposure device 50 includes a mask 51, a light source 52, and a contact drive unit 59. The mask 51 has a light-transmitting portion 51a and a light-shielding portion 51b, and is placed above the metal supporting board 1 being transported. The light-transmitting portion 51a is formed in a predetermined pattern in the mask 51. The light source 52 is mainly composed of a lamp 52a and a mirror 52b, and is placed so as to face the resist layer 5 with the mask 51 in between. The lamp 52a generates exposure light corresponding to the resist layer 5. The mirror 52b reflects the exposure light generated by the lamp 52a toward the mask 51.

[0035] Here, in the method for manufacturing the wired circuit board according to the present embodiment, before the exposure of the resist layer 5, the metal supporting board 1 is pressed toward the mask 51 by the contact driving unit 59 as shown by the hollow arrow in Fig. 6. Alternatively, the mask 51 is pressed toward the metal supporting board 1 by the contact driving unit 59. This brings the upper surface of the resist layer 5 into contact with the lower surface of the mask 51. At this time, a pressure equal to or greater than a predetermined pressure (compression force) is applied between the resist layer 5 and the mask 51.

[0036] The contact driving unit 59 may have, for example, a lower surface contact member that comes into contact with the lower surface of the metal supporting board 1, and an actuator that moves the lower surface contact member so that the metal supporting board 1 is pressed toward the mask 51. Alternatively, the contact driving unit 59 may have an upper surface contact member that comes into contact with the upper surface of the mask 51, and an actuator that moves the upper surface contact member so that the mask 51 is pressed toward the metal supporting board 1. Alternatively, the contact driving unit 59 may have a configuration that applies a pressure equal to or greater than a predetermined pressure (compression force) between the mask 51 and the resist layer 5 by reducing the air pressure in the space surrounding the contact portion when the lower surface of the mask 51 and the resist layer 5 are in contact with each other. The value of the predetermined pressure may be set to a different value depending on the configuration of the contact driving unit 59 that brings the mask 51 and the resist layer 5 into contact with each other.

[0037] With the resist layer 5 pressed against the lower surface of the mask 51, exposure light is generated from a light source 52, as shown in Fig. 7. In this case, light that passes through the light-transmitting portions 51a of the mask 51 is incident on the resist layer 5. This exposes the resist layer 5 in a predetermined pattern. This process of bringing the resist layer 5 and the mask 51 into contact with each other and performing exposure while applying a pressure between the resist layer 5 and the mask 51 that is equal to or greater than a predetermined pressure value is called hard contact exposure.

[0038] Next, as shown in FIG. 8 , the exposed resist layer 5 is developed. At this time, the resist layer 5 is developed by a first developing device 60. The first developing device 60 includes a plurality of developing nozzles 61. Each developing nozzle 61 is a spray nozzle arranged at a position above the transported metal supporting board 1, and sprays a developer toward the metal supporting board 1. When the resist layer 5 is made of a positive photosensitive resin, the exposed portions are dissolved in the developer and removed. As a result, openings 5 ​​a of a predetermined pattern are formed in the resist layer 5. In the openings 5 ​​a, the seed layer 3 is exposed upward. Of the openings 5 ​​a formed to extend in one direction, the pattern width of the openings 5 ​​a in a cross section perpendicular to the one direction is 1 μm or more and 6 μm or less.

[0039] Next, as shown in Fig. 9, a conductor layer 6 having a predetermined pattern is formed by electrolytic plating on the portion of the seed layer 3 exposed in the opening 5a (Fig. 8) of the resist layer 5. The thickness of the conductor layer 6 is 1 µm or more and 6 µm or less. Furthermore, the pattern width of the conductor layer 6 formed to extend in one direction in a cross section perpendicular to the one direction is 1 µm or more and 5 µm or less.

[0040] 10 , the entire resist layer 5 formed on the seed layer 3 is exposed so that the exposure light is incident on the entire resist layer 5 (hereinafter referred to as full-surface exposure). The exposure of the resist layer 5 is performed by a second exposure device 80. The second exposure device 80 includes a light source 81 but does not have a mask. Like the light source 52, the light source 81 mainly consists of a lamp 81 a and a mirror 81 b. Note that the second exposure device 80 may also include a transparent mask, i.e., a mask consisting only of a light-transmitting portion 51 a without a light-shielding portion 51 b.

[0041] The energy of exposure light irradiated per unit area of ​​an object when the object is exposed is called exposure dose. The unit of exposure dose is, for example, "mJ / cm ２". The exposure dose of the resist layer 5 is the integrated light amount of the exposure light irradiated from the second exposure device 80 toward the resist layer 5, and is determined by the illuminance of the exposure light irradiated toward the resist layer 5 and the irradiation time of the exposure light on the resist layer 5. Therefore, when the second exposure device 80 irradiates the resist film 5 with exposure light at a constant illuminance, the exposure dose of the resist layer 5 can be easily adjusted by adjusting the irradiation time. In the full exposure according to this embodiment, the exposure dose of the resist layer 5 is 5 mJ / cm ２ The exposure dose of the resist layer 5 is 100 mJ / cm ２ It is preferable that the concentration is 500 mJ / cm or more. ２ More preferably, it is equal to or greater than this.

[0042] 11 , the exposed resist layer 5 is developed. The resist layer 5 is developed by a second developing device 90. The second developing device 90 includes a plurality of developing nozzles 91, similar to the first developing device 60. Each developing nozzle 91 is a spray nozzle arranged above the metal supporting board 1 being transported, and sprays a developing solution toward the metal supporting board 1.

[0043] When the resist layer 5 is made of a positive photosensitive resin, the entire resist layer 5 is dissolved in a developer and removed. This exposes the portion of the seed layer 3 where the conductor layer 6 is not formed. Finally, as shown in FIG. 12 , the exposed unnecessary portion of the seed layer 3 is removed by, for example, wet etching. In this way, a laminate of the metal supporting board 1, the insulating layer 2, the seed layer 3, and the conductor layer 6 is completed as the wiring circuit board 7. The seed layer 3 and the conductor layer 6 formed in a predetermined pattern on the insulating layer 2 constitute the wiring of the wiring circuit board 7. The completed wiring circuit board 7 is taken up on a take-up roll.

[0044] [2] Configuration Example of a Roll-to-Roll Apparatus The above series of processes are continuously performed, for example, in a single roll-to-roll apparatus. Fig. 13 is a schematic diagram showing a configuration example of a roll-to-roll apparatus used in the method for manufacturing a wired circuit board.

[0045] The roll-to-roll apparatus 100 in Figure 13 includes a payout roll 110, an insulating layer forming apparatus 10, a seed layer forming apparatus 20, a resist coating apparatus 30, a heat treatment apparatus 40, a first exposure apparatus 50, a first developing apparatus 60, a plating apparatus 70, a second exposure apparatus 80, a second developing apparatus 90, an etching apparatus 95, and a take-up roll 120.

[0046] In the pay-out roll 110, a long metal supporting board 1 ( FIG. 1 ) is wound around a bobbin (not shown). When the pay-out roll 110 rotates, the metal supporting board 1 is paid out from the pay-out roll 110. The paid-out metal supporting board 1 is sent to the insulating layer forming apparatus 10. In FIG. 13 , the transport direction of the metal supporting board 1 paid out from the pay-out roll 110 is indicated by a dotted arrow.

[0047] 2 , the insulating layer forming apparatus 10 forms an insulating layer 2 on the metal supporting board 1. The metal supporting board 1 on which the insulating layer 2 has been formed is sent to the seed layer forming apparatus 20. As shown in the example of FIG. 3 , the seed layer forming apparatus 20 forms a seed layer 3 on the metal supporting board 1 so as to cover the insulating layer 2. The laminate consisting of the metal supporting board 1, the insulating layer 2, and the seed layer 3 is sent to the resist coating apparatus 30.

[0048] As shown in the example of FIG. 4 , the resist coating device 30 includes a coating nozzle 31 and forms a liquid film 4 of resist liquid 4p on the seed layer 3. The laminate with the liquid film 4 formed thereon is sent to a heat treatment device 40. The heat treatment device 40 includes, for example, a heater, and applies heat treatment to the liquid film 4 of resist liquid 4p ( FIG. 4 ). As a result, a resist layer 5 is formed on the seed layer 3, as shown in the example of FIG. 5 . The laminate with the resist layer 5 formed thereon is sent to a first exposure device 50.

[0049] 6 and 7 , the first exposure device 50 includes a mask 51, a light source 52, and a contact drive unit 59. The first exposure device 50 exposes the resist layer 5 in a predetermined pattern while bringing the resist layer 5 into contact with the mask 51. The laminate in which the resist layer 5 has been exposed in the predetermined pattern is sent to the first developing device 60.

[0050] 8 , the first developing device 60 includes a plurality of developing nozzles 61, and supplies a developer from the plurality of developing nozzles 61 onto the exposed resist layer 5. As a result, the exposed portions of the resist layer 5 are removed by the developer, and openings 5a of a predetermined pattern are formed in the resist layer 5. The laminate including the developed resist layer 5 is sent to a plating device 70.

[0051] As shown in the example of FIG. 9 , the plating device 70 forms a conductor layer 6 in the openings 5 ​​a ( FIG. 8 ) of the resist layer 5 by electrolytic plating. The laminate on which the conductor layer 6 of a predetermined pattern has been formed is sent to a second exposure device 80. As shown in the example of FIG. 10 , the second exposure device 80 is equipped with a light source 81. The second exposure device 80 exposes the entire surface of the resist layer 5. The laminate on which the entire resist layer 5 has been exposed is sent to a second developing device 90.

[0052] 11 , the second developing device 90 includes a plurality of developing nozzles 91, and supplies a developer from the plurality of developing nozzles 91 onto the exposed resist layer 5. As a result, the exposed resist layer 5 is entirely removed by the developer. The laminate from which the resist layer 5 has been removed is sent to an etching device 95.

[0053] 12 , the etching device 95 removes the exposed portion of the seed layer 3, for example, by wet etching. As a result, the seed layer 3 and the conductor layer 6 present on the insulating layer 2 are formed as wiring, completing the wired circuit board 7. The wired circuit board 7 completed in the etching device 95 is taken up on a take-up roll 120.

[0054] [3] Other Examples of Roll-to-Roll Apparatus In the present embodiment, the wired circuit board 7 may be produced using the following roll-to-roll apparatus instead of the roll-to-roll apparatus 100 of FIG. 13 . FIGS. 14 and 15 are schematic diagrams showing other configuration examples of roll-to-roll apparatuses used in the method for producing a wired circuit board. In this example, two roll-to-roll apparatuses 200 and 300 are used instead of the roll-to-roll apparatus 100 of FIG. 13 . The roll-to-roll apparatus 200 of FIG. 14 performs roughly the first half of the series of steps for producing the wired circuit board 7. On the other hand, the roll-to-roll apparatus 300 of FIG. 15 performs roughly the second half of the series of steps for producing the wired circuit board 7.

[0055] 14 includes a payout roll 110, an insulating layer forming apparatus 10, a seed layer forming apparatus 20, a resist coating apparatus 30, a heat treatment apparatus 40, and an intermediate take-up roll 130. In the roll-to-roll apparatus 200, the metal supporting board 1 paid out from the payout roll 110 is sent sequentially to the insulating layer forming apparatus 10, the seed layer forming apparatus 20, the resist coating apparatus 30, and the heat treatment apparatus 40. In Fig. 14, as in the example of Fig. 13, the transport direction of the metal supporting board 1 paid out from the payout roll 110 is indicated by a dotted arrow.

[0056] The insulating layer forming apparatus 10, seed layer forming apparatus 20, resist coating apparatus 30, and heat treatment apparatus 40 in Fig. 14 have the same configurations as the components denoted by the same reference numerals in Fig. 13. As a result, the insulating layer 2, seed layer 3, and resist layer 5 are formed sequentially on the metal supporting board 1. The laminate ML after the resist layer 5 is formed by the heat treatment apparatus 40 is taken up by the intermediate take-up roll 130.

[0057] 15 includes an intermediate payout roll 140, a first exposure unit 50, a first developing unit 60, a plating unit 70, a second exposure unit 80, a second developing unit 90, an etching unit 95, and a take-up roll 120. As the intermediate payout roll 140, the intermediate take-up roll 130 of the roll-to-roll apparatus 200 of FIG.

[0058] In the roll-to-roll apparatus 300, the laminate ML unwound from the intermediate feed roll 140 is sequentially sent to the first exposure device 50, the first developing device 60, the plating device 70, the second exposure device 80, the second developing device 90, and the etching device 95. In Fig. 15, similar to the example of Fig. 13, the transport direction of the laminate ML unwound from the intermediate feed roll 140 is indicated by a dotted arrow.

[0059] The first exposure device 50, first developing device 60, plating device 70, second exposure device 80, second developing device 90, and etching device 95 in Figure 15 have the same configurations as the components denoted by the same reference numerals in Figure 13. As a result, the resist layer 5 formed on the metal supporting board 1 is exposed to light in a predetermined pattern and developed. Furthermore, a conductor layer 6 is formed in the openings 5a of the resist layer 5 formed by development. Furthermore, the entire surface of the resist layer 5 is exposed to light and developed. Furthermore, the exposed seed layer 3 is removed. The wired circuit board 7 after the seed layer 3 has been removed by the etching device 95 is taken up on the take-up roll 120.

[0060] [4] Effects (1) In the present embodiment, after the feeding roll 110 of the metal supporting board 1 is prepared, all of the multiple processing steps until the wired circuit board 7 is completed are performed by roll-to-roll. This makes it possible to manufacture the wired circuit board 7 with high production efficiency.

[0061] The resist layer 5 is formed by applying a resist liquid 4p onto the insulating layer 2 and then heat-treating the liquid film 4 of the applied resist liquid 4p. The thickness of the liquid film 4 formed on the insulating layer 2 can be reduced by adjusting the amount of resist liquid 4p supplied onto the insulating layer. In this case, the thickness of the resist layer 5 can be made sufficiently smaller than that of a resist layer formed using a dry film resist. A smaller thickness of the resist layer 5 makes it possible to form openings 5a in the resist layer 5 in a finer pattern.

[0062] As a result, it becomes possible to manufacture the wired circuit board 7 having a fine conductor pattern with high production efficiency.

[0063] (2) When the resist layer 5 is exposed using the mask 51, a pressure equal to or greater than a predetermined pressure acts between the mask 51 and the resist layer 5 while the mask 51 and the resist layer 5 are in contact with each other. This fixes the positional relationship between the mask 51 and the resist layer 5. Furthermore, since no gap (space) is formed between the mask 51 and the resist layer 5, the spread of exposure light is suppressed. As a result, it is possible to expose a fine pattern with high precision.

[0064] (3) In this embodiment, a supporting board made of stainless steel is used as the metal supporting board 1. The metal supporting board 1 made of stainless steel has relatively high rigidity. For example, the metal supporting board 1 made of stainless steel has higher rigidity than a metal supporting board made of copper. This reduces the occurrence of undulations in the part of the metal supporting board 1 located between the payout roll and the take-up roll in roll-to-roll printing. Therefore, the shape of the metal supporting board 1 is easily maintained flat during transportation. In this case, the thickness of the resist layer 5 formed on the metal supporting board 1 is less likely to vary, enabling exposure of a fine pattern with high accuracy. Furthermore, because the metal supporting board 1 made of stainless steel is less likely to deform, the positional accuracy during exposure is improved. Therefore, deformation of the pattern of the openings 5 ​​a formed in the resist layer 5 due to deformation of the metal supporting board 1 is reduced.

[0065] Furthermore, stainless steel has a relatively low thermal conductivity as a metal material. For example, a metal supporting board 1 made of stainless steel has a lower thermal conductivity than a metal supporting board made of copper. As a result, when the liquid film 4 of the resist liquid 4p is subjected to a heat treatment, the metal supporting board 1 prevents the temperature of the liquid film 4 from rising sharply. As a result, the solvent component of the liquid film 4 is appropriately removed.

[0066] (4) In this embodiment, the resist layer 5 is made of a positive photosensitive resin. After the conductor layer 6 is formed, the entire resist layer 5 is exposed and developed. Therefore, after the conductor layer 6 is formed in the opening 5 a of the resist layer 5, the portion of the resist layer 5 adjacent to the conductor layer 6 is dissolved in a developer (alkaline solution). This makes it possible to easily remove unnecessary resist layer 5 from the metal supporting board 1 after the conductor layer 6 is formed. As a result, it is possible to prevent a portion of the resist layer 5 from remaining as foreign matter on the produced wired circuit board 7. It is also possible to prevent poor removal of the seed layer 3 due to a portion of the resist layer 5 remaining. Therefore, it is possible to prevent short circuits from occurring between multiple wirings on the wired circuit board 7.

[0067] (5) In this embodiment, the insulating layer 2 is made of photosensitive polyimide. In this case, forming the insulating layer 2 using photolithography technology allows the insulating layer 2 to be thinned. Also, the insulating layer 2 can be easily formed into a desired pattern. Furthermore, when the insulating layer 2 is formed of photosensitive polyimide, the surface of the insulating layer 2 can be made mirror-finished without the need for mechanical or chemical processing. When the surface of the insulating layer 2 is mirror-finished, scattering of exposure light incident on the insulating layer 2 at the surface of the insulating layer 2 during exposure of the resist layer 5 is suppressed. This makes it possible to form openings 5a in an even finer pattern in the resist layer 5.

[0068] [5] Other Embodiments (1) In the above embodiment, the multiple processing steps for forming the wired circuit board 7 are performed by one roll-to-roll apparatus 100 or two roll-to-roll apparatuses 200, 300, but the present invention is not limited to this. The multiple processing steps for forming the wired circuit board 7 may be performed using three or more roll-to-roll apparatuses. Alternatively, each of the multiple processing steps for forming the wired circuit board 7 may be performed by a separate roll-to-roll apparatus.

[0069] (2) In the above embodiment, the payout roll 110 around which the long metal supporting board 1 is wound is first prepared, but the present invention is not limited to this. Instead of the payout roll 110 of the metal supporting board 1, a roll of a two-layer base material in which the metal supporting board 1 and the insulating layer 2 are laminated may be prepared as the payout roll 110. In this case, the step of forming the insulating layer 2 on the metal supporting board 1 ( FIG. 2 ) can be omitted.

[0070] (3) In the above embodiment, during exposure to form the openings 5 ​​a of the predetermined pattern in the resist layer 5, the resist layer 5 is pressed against the lower surface of the mask 51 with a predetermined force. Alternatively, the mask 51 is pressed against the upper surface of the resist layer 5 with a predetermined force. However, the present invention is not limited to these examples. During exposure to form the openings 5 ​​a of the predetermined pattern in the resist layer 5, the resist layer 5 and the mask 51 may be kept spaced apart from each other.

[0071] Alternatively, during exposure to form openings 5 ​​a of a predetermined pattern in resist layer 5, resist layer 5 and mask 51 may be kept in contact with each other at a pressure lower than the predetermined pressure in the above embodiment. This process of bringing resist layer 5 and mask 51 into contact with each other and performing exposure while applying a pressure lower than a predetermined value between resist layer 5 and mask 51 is called soft contact exposure.

[0072] (4) In the above embodiment, a positive photosensitive phenolic resin or a positive acrylic resin is used as the material for the resist layer 5, but the present invention is not limited to this. The resist layer 5 may be made of a positive epoxy resin or a positive photosensitive polyimide.

[0073] (5) In the above embodiment, a positive photosensitive resin is used as the material for the resist layer 5, but the present invention is not limited to this. Instead of a positive photosensitive resin, a negative photosensitive resin may be used as the material for the resist layer 5. In this case, when removing the resist layer 5 after the conductor layer 6 is formed, the resist layer 5 is removed using, for example, a solvent or a stripping solution containing the same components as the developer for the photosensitive resin. This eliminates the need for a process of exposing and developing the entire resist layer 5.

[0074] (6) In the above embodiment, a supporting substrate made of stainless steel is used as the metal supporting substrate 1, but the present invention is not limited to this. As the metal supporting substrate 1, a supporting substrate made of copper, a supporting substrate made of nickel, a supporting substrate made of a copper alloy, or the like can also be used instead of a supporting substrate made of stainless steel.

[0075] (7) In the above embodiment, the seed layer 3 is formed on the insulating layer 2 in order to form the conductor layer 6 by electrolytic plating, but the present invention is not limited to this. If the conductor layer 6 is formed by, for example, electroless plating, the seed layer 3 does not need to be formed.

[0076] (8) In the above embodiment, photosensitive polyimide is used as the material of the insulating layer 2, but the present invention is not limited to this. Resins other than photosensitive polyimide (such as phenolic resin, acrylic resin, or epoxy resin) may also be used as the material of the insulating layer 2.

[0077] (9) In the above embodiment, the resist layer 5 formed on the seed layer 3 can be removed without exposure and development by using a stripping solution containing the same components as the developer for the photosensitive resin. Therefore, after the conductor layer 6 is formed, the unnecessary resist layer 5 may be removed using a stripping solution instead of exposing the entire surface of the resist layer 5 to light and developing it.

[0078] When removing the resist layer 5 using a stripper, it takes longer to dissolve the resist layer 5 than when removing the resist layer 5 by full-surface exposure and development. In this case, the processing environment must be maintained at a temperature higher than room temperature (e.g., about 40°C to 50°C) to promote and stabilize the reaction between the resist layer 5 and the stripper. This may result in oxidation of the previously formed conductor layer 6 by the stripper, resulting in a deterioration in the electrical properties of the wiring. Therefore, it is preferable to remove the resist layer 5 by full-surface exposure and development, as shown in the above embodiment.

[0079] [6] Correspondence between each component of the claims and each part of the embodiments Examples of correspondence between each component of the claims and each element of the embodiments will be described below, but the present invention is not limited to the following examples. In the above-described embodiments, the wired circuit board 7 is an example of a wired circuit board, the metal supporting board 1 is an example of a metal supporting board, the insulating layer 2 is an example of an insulating layer, and the resist layer 5 is an example of a plating resist layer. Also, the opening 5a is an example of an opening, the conductor layer 6 is an example of a conductor layer, the mask 51 is an example of a mask, and the seed layer 3 is an example of a seed layer. Various other elements having the configuration or function described in the claims can also be used as each component of the claims.

[0080] [7] Line and Space Verification Test (Example and Comparative Example) In order to confirm the effects of the method for manufacturing a wired circuit board according to the above embodiment, the inventors fabricated wired circuit boards of Example 1 and Comparative Examples 1 to 4, which were manufactured by different methods. When fabricating these wired circuit boards, a test mask was used in which a light-projecting portion was formed with a pattern corresponding to multiple types of line and space. Here, line and space refers to the width of the wiring and the spacing between adjacent wiring in the wired circuit board, and is expressed as L / S.

[0081] Specifically, the test masks used to fabricate the wired circuit boards of Example 1 and Comparative Examples 1 to 4 had light-projecting portions formed in nine patterns corresponding to nine L / Ss of 1 μm / 1 μm, 2 μm / 2 μm, 3 μm / 3 μm, 4 μm / 4 μm, 5 μm / 5 μm, 6 μm / 6 μm, 7 μm / 7 μm, 8 μm / 8 μm, and 9 μm / 9 μm. The inventors compared the minimum L / S that allowed wiring to be formed for the wired circuit boards of Example 1 and Comparative Examples 1 to 4.

[0082] The wired circuit board of Example 1 was fabricated according to the method for manufacturing a wired circuit board according to the above-described embodiment (see FIGS. 1 to 12 ). Specifically, when fabricating the wired circuit board of Example 1, an insulating layer 2 made of photosensitive polyimide was formed on a metal supporting board 1, and a seed layer 3 was further formed on the insulating layer 2. Furthermore, a resist liquid 4p was applied to the seed layer 3 and heat-treated, thereby forming a resist layer 5 made of a positive photosensitive resin on the seed layer 3. The thickness of the resist layer 5 was 3 μm. Furthermore, when exposing the resist layer 5, hard contact exposure was performed using the above-described test mask. In this hard contact exposure, the metal supporting board 1 was pressed against the mask 51 so that a pressure of 0.5 MPa was applied between the resist layer 5 and the mask 51.

[0083] In the completed wired circuit board of Example 1, wiring with an L / S of 2 μm / 2 μm to 9 μm / 9 μm was formed. On the other hand, wiring with an L / S of 1 μm / 1 μm was not formed. That is, for the wired circuit board of Example 1, the minimum L / S at which wiring could be formed was 2 μm / 2 μm. The thickness of the wiring formed on the wired circuit board of Example 1 was 2 μm.

[0084] The wired circuit board of Comparative Example 1 was produced by the same method as the wired circuit board of Example 1, except for the following points. When producing the wired circuit board of Comparative Example 1, a resist layer 5 was formed by attaching a dry film resist to a seed layer 3. The resist layer 5 was made of a negative photosensitive resin and had a thickness of 10 μm. When producing the wired circuit board of Comparative Example 1, after the conductor layer 6 was formed, the film-like resist layer 5 was peeled off from the seed layer 3. In the completed wired circuit board of Comparative Example 1, wiring with an L / S of 6 μm / 6 μm to 9 μm / 9 μm was formed. On the other hand, wiring with an L / S of 1 μm / 1 μm to 5 μm / 5 μm was not formed. That is, for the wired circuit board of Comparative Example 1, the minimum L / S at which wiring could be formed was 6 μm / 6 μm. The thickness of the wiring formed on the wired circuit board of Comparative Example 1 was 6 μm.

[0085] The wired circuit board of Comparative Example 2 was produced using the same method as the wired circuit board of Comparative Example 1, except that the thickness of the dry film resist used was changed. When producing the wired circuit board of Comparative Example 2, the thickness of the resist layer 5 formed on the seed layer 3 was 15 μm. In the completed wired circuit board of Comparative Example 2, wiring with an L / S of 8 μm / 8 μm to 9 μm / 9 μm was formed. On the other hand, wiring with an L / S of 1 μm / 1 μm to 7 μm / 7 μm was not formed. That is, for the wired circuit board of Comparative Example 2, the minimum L / S at which wiring could be formed was 8 μm / 8 μm. The thickness of the wiring formed on the wired circuit board of Comparative Example 2 was 8 μm.

[0086] The wired circuit board of Comparative Example 3 was fabricated using the same method as the wired circuit board of Comparative Example 1, except that the exposure method for the resist layer 5 was changed. When fabricating the wired circuit board of Comparative Example 3, when exposing the resist layer 5 to a predetermined pattern, exposure light was irradiated onto the resist layer 5 from an exposure device while the resist layer 5 and the test mask were spaced apart by a small distance. This type of exposure process is called proximity exposure. In proximity exposure, the distance between the resist layer 5 and the mask (in this example, the test mask) is maintained at, for example, approximately several tens of μm. In the completed wired circuit board of Comparative Example 3, wiring with an L / S of 6 μm / 6 μm to 9 μm / 9 μm was formed. On the other hand, wiring with an L / S of 1 μm / 1 μm to 5 μm / 5 μm was not formed. That is, for the wired circuit board of Comparative Example 3, the minimum L / S at which wiring could be formed was 6 μm / 6 μm. The thickness of the wiring formed on the wired circuit board of Comparative Example 3 was 6 μm.

[0087] The wired circuit board of Comparative Example 4 was produced by the same method as the wired circuit board of Comparative Example 3, except that the thickness of the dry film resist used was changed. When producing the wired circuit board of Comparative Example 4, the thickness of the resist layer 5 formed on the seed layer 3 was 20 μm. In the completed wired circuit board of Comparative Example 4, wiring with an L / S of 6 μm / 6 μm to 9 μm / 9 μm was formed. On the other hand, wiring with an L / S of 1 μm / 1 μm to 5 μm / 5 μm was not formed. That is, for the wired circuit board of Comparative Example 4, the minimum L / S at which wiring could be formed was 6 μm / 6 μm. The thickness of the wiring formed on the wired circuit board of Comparative Example 4 was 6 μm.

[0088] The differences between the manufacturing methods of the wired circuit boards of Example 1 and Comparative Examples 1 to 4 and the evaluation results of the completed wired circuit boards (the minimum L / S at which wiring could be formed) are shown in the following Table 1. For the wired circuit boards of Example 1 and Comparative Examples 1 to 4, a metal supporting board 1 made of stainless steel and having a thickness of 20 μm was used.

[0089]

[0090] As described above, the thickness (3 μm) of the resist layer 5 formed on the wired circuit board of Example 1 is sufficiently smaller than the thickness (10 μm to 20 μm) of the resist layer 5 formed on the wired circuit boards of Comparative Examples 1 to 4. This shows that when the resist liquid 4 p is applied and heat treated, it is possible to form a resist layer 5 that is sufficiently thinner than when an existing dry film resist is used.

[0091] As a result, in the completed wired circuit boards of Example 1 and Comparative Examples 1 to 4, the minimum L / S of Example 1 (2 μm / 2 μm) is sufficiently smaller than the minimum L / S of Comparative Example 1 (6 μm / 6 μm), the minimum L / S of Comparative Example 2 (8 μm / 8 μm), the minimum L / S of Comparative Example 3 (6 μm / 6 μm), and the minimum L / S of Comparative Example 4 (6 μm / 6 μm).

[0092] [8] Confirmation Test for Peeling of Resist Layer (Examples and Comparative Examples) As described above, in the method for producing a wired circuit board according to one aspect of the present invention, the unnecessary resist layer 5 after the formation of the conductor layer 6 may be removed by performing full-surface exposure and development, or may be removed using a stripping solution without performing full-surface exposure and development. The inventors produced wired circuit boards of Examples 1 to 6 and Comparative Examples 1 to 4, which were produced by different manufacturing methods, in order to confirm the peeling ability of the unnecessary resist layer 5 after the formation of the conductor layer 6 according to the removal method and removal conditions.

[0093] The wired circuit board of Example 1 used in this confirmation test is the same as the wired circuit board of Example 1 produced in the line-and-space confirmation test. As described above, the wired circuit board of Example 1 was produced according to the method for producing a wired circuit board shown in FIGS.

[0094] In the production of the wired circuit board of Example 1, the exposure dose of the resist layer 5 was set to 2000 mJ / cm 2 during the entire surface exposure for removing unnecessary resist layer 5 after the formation of the conductor layer 6. ２In this overall exposure, an ultraviolet irradiator (model UV-2001M-ND) manufactured by Minaga Electric Manufacturing Co., Ltd. was used. In the overall exposure, the energy (illuminance) of the exposure light (ultraviolet rays including at least a part of g-rays, h-rays, and i-rays) irradiated from the ultraviolet irradiator onto the resist layer 5 per unit area and per unit time was 90 mJ / cm. ２ It was.

[0095] Furthermore, in the production of the wired circuit board of Example 1, a developer (P-10) manufactured by Tokyo Ohka Kogyo Co., Ltd. was used during development to remove unnecessary resist layer 5 after the formation of conductor layer 6. This development was performed in a temperature environment set to 25°C and for a development time of 100 seconds.

[0096] The wired circuit boards of Examples 2 to 5 used in this confirmation test were produced in the same manner as the wired circuit board of Example 1, except that the exposure dose of the resist layer 5 during the entire surface exposure of the resist layer 5 was different. Specifically, the wired circuit board of Example 2 was produced by setting the exposure dose of the resist layer 5 to 5 mJ / cm during the entire surface exposure. ２ In the printed circuit board of Example 3, the exposure dose of the resist layer 5 during the entire surface exposure was 100 mJ / cm ２ In the printed circuit board of Example 4, the exposure dose of the resist layer 5 during the entire surface exposure was 500 mJ / cm ２ In the printed circuit board of Example 5, the exposure dose of the resist layer 5 during the entire surface exposure was 1000 mJ / cm ２ It was decided.

[0097] The wired circuit board of Example 6 used in this confirmation test was produced in the same manner as the wired circuit board of Example 1, except that after the formation of the conductor layer 6, the unnecessary resist layer 5 was removed using a stripping solution without performing full-surface exposure and development.

[0098] The wired circuit boards of Comparative Examples 1 to 4 used in this confirmation test were the same as those produced in the line-and-space confirmation test. As described above, when producing the wired circuit boards of Comparative Examples 1 to 4, a resist layer 5 was formed using a dry film resist. Furthermore, after the formation of the conductor layer 6, the unnecessary resist layer 5 was removed by physically peeling it off from the seed layer 3. In this way, for the wired circuit boards of Comparative Examples 1 to 4, the unnecessary resist layer 5 after the formation of the conductor layer 6 was not subjected to full-surface exposure and development.

[0099] In the following description, the part of the resist layer 5 remaining on the wirings and their surrounding areas after the unnecessary resist layer 5 has been removed will be referred to as resist residue.

[0100] The present inventors confirmed the presence or absence of resist residues for the wired circuit boards of Examples 1 to 6 and Comparative Examples 1 to 4 produced as described above by acquiring secondary electron images using a SEM (scanning electron microscope) at an acceleration voltage of 15 kV and a magnification of 1500 times. As a result, the presence of resist residues was not observed for the wired circuit boards of Examples 1 to 5. On the other hand, the presence of resist residues was observed for the wired circuit boards of Example 6 and Comparative Examples 1 to 4.

[0101] The present inventors also examined the wired circuit boards of Examples 1 to 6 and Comparative Examples 1 to 4 prepared as described above using an optical microscope at a magnification of 20x to check for the presence or absence of resist residue. As a result, the presence of resist residue was not observed in the wired circuit boards of Examples 1 to 6. On the other hand, the presence of resist residue was observed in the wired circuit boards of Comparative Examples 1 to 4.

[0102] Furthermore, the inventors determined resist residue occurrence levels A, B, and C for the wired circuit boards of Examples 1 to 6 and Comparative Examples 1 to 4 as comprehensive confirmation results regarding resist residues from the results of confirmation of each wired circuit board using an SEM and an optical microscope. Here, resist residue occurrence level A represents a case in which no resist residue was observed in the confirmation results using either an SEM or an optical microscope. Resist residue occurrence level B represents a case in which no resist residue was observed in the confirmation results using either an SEM or an optical microscope. Resist residue occurrence level C represents a case in which resist residue was observed in the confirmation results using both an SEM and an optical microscope.

[0103] In this case, the level of resist residue generation for the wired circuit boards of Examples 1 to 5 is A. On the other hand, the level of resist residue generation for the wired circuit boards of Example 6 and Comparative Example 4 is B. On the other hand, the level of resist residue generation for the wired circuit boards of Comparative Examples 1 to 3 is C. The results of the confirmation test regarding the peeling of the resist layer are shown in Table 2 below. Table 2 below shows the test results, as well as whether or not full-surface exposure was performed when removing unnecessary resist layer 5 after formation of conductor layer 6, and the exposure amount during full-surface exposure.

[0104]

[0105] As described above, the unnecessary resist layer 5 in the wired circuit boards of Examples 1 to 6 was removed by 5 mJ / cm ２ In the wired circuit boards of Examples 1 to 5 obtained by full-surface exposure and development at the above exposure dose, the generation of resist residue was not observed. In contrast, the generation of resist residue was observed by SEM in the wired circuit board of Example 6, in which the unnecessary resist layer 5 was removed with a stripping solution without full-surface exposure and development, among the wired circuit boards of Examples 1 to 6. Furthermore, the generation of resist residue was observed at least by SEM in the wired circuit boards of Comparative Examples 1 to 4, in which the unnecessary resist layer 5 was removed by peeling off the dry film resist. Therefore, in order to suppress the generation of resist residue, it is necessary to remove the unnecessary resist layer 5 at 5 mJ / cm ２It was found that it is preferable to expose the entire surface with the above exposure amount and then develop.

Claims

1. A step of preparing a laminate in which an insulating layer is formed on a long metal supporting board; forming a plating resist layer containing a photosensitive material on the insulating layer by roll-to-roll; exposing the plating resist layer to a predetermined pattern by roll-to-roll exposure; developing the plating resist layer exposed in the predetermined pattern by roll-to-roll processing to form openings in the plating resist layer having the predetermined pattern or a pattern opposite to the predetermined pattern; forming a conductor layer in the opening by roll-to-roll; The step of forming the plating resist layer includes applying a photosensitive plating resist liquid onto the insulating layer, and subjecting the applied plating resist liquid to a heat treatment.

2. 2. The method for manufacturing a printed circuit board according to claim 1, wherein the step of exposing the plating resist layer to the predetermined pattern includes performing contact exposure in which a mask corresponding to the predetermined pattern and the plating resist layer are brought into contact with each other and exposure light is irradiated onto the plating resist layer through the mask.

3. 3. The method for producing a printed circuit board according to claim 2, wherein the contact exposure includes applying a pressure equal to or greater than a predetermined pressure between the mask and the plating resist layer while the mask and the plating resist layer are in contact with each other.

4. The method for producing a wired circuit board according to any one of claims 1 to 3, wherein the metal supporting board is made of stainless steel.

5. The plating resist liquid is made of a positive photosensitive resin, The method for producing the printed circuit board includes: a step of exposing the entire plating resist layer by roll-to-roll after the step of forming the conductor layer; The method for producing a wired circuit board according to any one of claims 1 to 3, further comprising the step of developing the plating resist layer entirely exposed by roll-to-roll to remove the plating resist layer on the insulating layer.

6. After the step of forming the conductor layer, in the step of exposing the entirety of the plating resist layer, the exposure dose of the plating resist layer is 5 mJ / cm ２ The method for producing a wired circuit board according to claim 5, wherein the wiring circuit board is made of a material selected from the group consisting of fluororesin, ...rubber, and fluororesin.

7. The method for producing a wired circuit board according to any one of claims 1 to 3, wherein the insulating layer is made of a photosensitive polyimide.

8. The method further includes forming a seed layer on the insulating layer by roll-to-roll after the step of preparing the laminate and before the step of forming the plating resist layer, In the step of forming a plating resist layer, the plating resist layer is formed on the insulating layer via the seed layer, 4. The method for producing a wired circuit board according to claim 1, wherein the step of forming the conductor layer includes forming the conductor layer on the seed layer exposed in the opening by electrolytic plating.