Manufacturing method of copper-clad laminates

Abstract

To provide a copper-clad laminate in which the cross-sectional shape of a wiring can be easily made rectangular and in which abnormality in current supply to a conductor layer is less likely to occur when the wiring pattern is formed with the semi-additive method.SOLUTION: A copper-clad laminate 1 includes a conductor layer 20 formed on the surface of a base film 10. In the conductor layer 20, a power feeding region A1 which is a region near one or both edges along the MD direction is thicker than a wiring forming region A2 which is all or a part of the other region. Since the conductor layer 20 in the wiring forming region A2 is thin, it is easy to make the cross-sectional shape of the wiring rectangular when the wiring pattern is formed by the semi-additive method. Furthermore, since the conductor layer 20 in the power feeding region A1 is thick, current supply abnormalities in the conductor layer 20 are less likely to occur.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a copper-clad laminate. Manufacturing method More specifically, the present invention relates to a copper-clad laminate used in the manufacture of flexible printed wiring boards (FPCs) and the like. Manufacturing method

Background Art

[0002] In electronic devices such as liquid crystal panels, notebook computers, digital cameras, and mobile phones, flexible printed wiring boards having wiring patterns formed on the surfaces of resin films are used.

[0003] A flexible printed wiring board can be obtained by forming a wiring pattern on a copper-clad laminate by a semi-additive method, a subtractive method, or the like. In particular, when fine wiring formation or high-precision wiring dimensions are required, the semi-additive method is used.

[0004] The manufacture of a flexible printed wiring board by the semi-additive method is carried out in the following procedure. First, a resist layer is formed on the surface of the conductor layer of the copper-clad laminate. Next, openings are formed in the portion of the resist layer where the wiring pattern is to be formed. Next, electrolytic plating is carried out with the conductor layer exposed from the openings of the resist layer as the cathode to form the wiring portion. Next, the resist layer is removed, and the conductor layer other than the wiring portion is removed by flash etching or the like. Thereby, a flexible printed wiring board is obtained.

[0005] In the semi-additive method, unnecessary portions of the conductor layer of the copper-clad laminate are removed by etching. If the conductor layer is too thick, the etching time becomes long, and the etching of the wiring portion also progresses, making it difficult to make the cross-sectional shape of the wiring rectangular. Therefore, from the viewpoint of making the cross-sectional shape of the wiring rectangular, it is preferable that the conductor layer of the copper-clad laminate be thin.

[0006] However, if the conductor layer is thin, problems can arise when forming the wiring section by electroplating. Specifically, to form the wiring section by electroplating, electrode terminals are connected to the edge of the conductor layer and power is supplied to the conductor layer. Here, if the conductor layer is thin, the electrical resistance is high, making it difficult to supply sufficient current. In addition, the part of the conductor layer that comes into contact with the electrode terminals becomes high voltage, which can cause dissolution or abnormal deposition of the conductor layer, hindering the current supply.

[0007] Therefore, by setting a low current density in electroplating, the dissolution of the conductive layer is prevented. For example, Patent Document 1 describes forming wiring on a substrate having a nickel-chromium alloy film with a thickness of 10 nm and a copper layer with a thickness of 100 nm using a semi-additive method, where the current density is set to 1 A / dm 2 It is stated that this should be done. However, if the current density is too low, stable electroplating becomes difficult. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2010-108964 [Overview of the project] [Problems that the invention aims to solve]

[0009] In view of the above circumstances, the present invention provides a copper-clad laminate that makes it easier to form a rectangular cross-sectional shape of the wiring when forming a wiring pattern by the semi-additive method, and that is less prone to current supply abnormalities in the conductor layer. Manufacturing method The purpose is to provide. [Means for solving the problem]

[0010] The present invention provides a method for manufacturing a copper-clad laminate, comprising: an electrolytic plating step to obtain an intermediate copper-clad laminate by conveying a substrate by roll-to-roll and forming a copper plating film on the surface of the substrate by electrolytic plating; and a cutting step to obtain a final copper-clad laminate by cutting the intermediate copper-clad laminate with a slitter, wherein in the electrolytic plating step, a shielding plate is placed between the substrate and the anode to reduce the current density in a predetermined region of the substrate, thereby forming a conductive layer having a strip-shaped thick film region and a thin film region along the MD direction; and in the cutting step, the intermediate copper-clad laminate is cut in the thick film region to form a final copper-clad laminate having a conductive layer in which the power supply region, which is the region near the edge along the MD direction, is thicker than the wiring formation region, which is all or part of the other region. [Effects of the Invention]

[0011] According to the present invention, since the conductor layer in the wiring formation region is thin, when forming a wiring pattern by the semi-additive method, it is easy to make the cross-sectional shape of the wiring rectangular. Also, since the conductor layer in the power supply region is thick, abnormal current supply of the conductor layer is unlikely to occur.

Brief Description of the Drawings

[0012] [Figure 1] It is a partially enlarged cross-sectional view of a copper-clad laminate according to an embodiment. [Figure 2] FIG. (A) is a plan view of a copper-clad laminate according to an embodiment. FIG. (B) is a cross-sectional view of the same copper-clad laminate. [Figure 3] It is an explanatory diagram showing a manufacturing procedure of a flexible printed wiring board by the semi-additive method. [Figure 4] FIG. (B) is a cross-section of a copper-clad laminate of the second embodiment. FIG. (B) is a cross-section of a copper-clad laminate of the third embodiment. FIG. (B) is a cross-section of a copper-clad laminate of the fourth embodiment. [Figure 5] It is an explanatory diagram showing a manufacturing procedure of a copper-clad laminate. [Figure 6] It is an explanatory diagram showing a manufacturing procedure of other embodiments.

Modes for Carrying Out the Invention

[0013] Next, embodiments of the present invention will be described based on the drawings. 〔Copper-Clad Laminate〕 As shown in FIG. 1, a copper-clad laminate 1 according to an embodiment of the present invention includes a base film 10 and a conductor layer 20 formed on the surface of the base film 10.

[0014] As the base film 10, a resin film such as a polyimide film or a liquid crystal polymer (LCP) film can be used. Although not particularly limited, the thickness of the base film 10 is generally 10 to 100 μm.

[0015] The conductor layer 20 is composed of a metal layer 21 formed by a dry film-forming method such as sputtering and a copper plating film 22 formed by electrolytic plating. The metal layer 21 and the copper plating film 22 are laminated in this order on the surface of the base film 10.

[0016] The metal layer 21 is composed of an underlayer metal layer 21a and a copper thin film layer 21b. The underlayer metal layer 21a and the copper thin film layer 21b are laminated in this order on the surface of the base film 10. Generally, the underlayer metal layer 21a is made of nickel, chromium, or a nickel-chromium alloy. The underlayer metal layer 21a may not be provided. The copper thin film layer 21b may be formed on the surface of the base film 10 via the underlayer metal layer 21a, or may be directly formed on the surface of the base film 10 without passing through the underlayer metal layer 21a. The thickness of the underlayer metal layer 21a is generally 5 to 50 nm, and the thickness of the copper thin film layer 21b is generally 50 to 400 nm.

[0017] As shown in FIGS. 2(A) and 2(B), the main surface of the copper-clad laminate 1 has a power supply region A1 and a wiring formation region A2. The conductor layer 20 is thicker in the power supply region A1 than in the wiring formation region A2. As will be described later, when processing the copper-clad laminate 1 by the semi-additive method, an electrolytic plating electrode terminal is connected to the power supply region A1, and a wiring pattern is formed in the wiring formation region A2.

[0018] The power supply region A1 is a strip-shaped region near the edge along the MD direction (Machine Direction) of the copper-clad laminate 1. The copper-clad laminate 1 of the present embodiment has two power supply regions A1 along both the left and right edges. The wiring formation region A2 is all or a part of the region other than the power supply region A1. In the present embodiment, the wiring formation region A2 is a strip-shaped region between the two power supply regions A1.

[0019] In this embodiment, the copper-clad laminate 1 has an intermediate region between the wiring formation region A2 and the power supply region A1. In this sense, the wiring formation region A2 is a part of the region other than the power supply region A1. The conductor layer 20 gradually thins in the intermediate region from the power supply region A1 side toward the wiring formation region A2 side. The intermediate region does not have to exist in substance. That is, the thickness of the conductor layer 20 may change in a stepwise manner between the wiring formation region A2 and the power supply region A1. In this case, the wiring formation region A2 is the entire region other than the power supply region A1.

[0020] The width of the first power supply area A1 is not particularly limited, but is 5 to 50 mm, as long as it is wide enough to connect the electrode terminals of the electroplating. The wiring formation area A2 usually occupies most of the main surface of the copper-clad laminate 1. Although not particularly limited, the wiring formation area A2 is wider than the power supply area A1. The intermediate area is preferably narrower. Although not particularly limited, the intermediate area is preferably narrower than the power supply area A1.

[0021] Flexible printed circuit boards can be manufactured by processing copper-clad laminates 1 using the semi-additive method. Furthermore, if long strip-shaped copper-clad laminates 1 are used, they can be processed using a roll-to-roll method. Figure 3 shows the manufacturing procedure for flexible printed circuit boards using the semi-additive method. Specifically, the copper-clad laminates 1 are processed in the following steps.

[0022] (1) First, a resist layer 31 is formed on the surface of the conductor layer 20 of the copper-clad laminate 1. Here, the resist layer 31 is formed in the wiring formation region A2. The conductor layer 20 in the power supply region A1 is left exposed.

[0023] (2) Next, an opening is formed in the portion of the resist layer 31 where the wiring pattern will be formed.

[0024] (3) Next, electroplating is performed using the conductive layer 20 exposed from the opening of the resist layer 31 as the cathode, and a plating layer 32 is laminated. At this point, the electrode terminals of the electroplating are connected to the power supply region A1 of the conductive layer 20, and power is supplied to the conductive layer 20.

[0025] (4) Next, the resist layer 31 is removed, and the conductor layer 20 other than the wiring area is removed by flash etching or the like. This forms a wiring pattern in the wiring formation area A2. After that, unnecessary parts such as the power supply area A1 (and intermediate area) may be cut off to obtain individual pieces of flexible printed circuit board.

[0026] In step (3), electroplating, the electrode terminals are connected to the power supply region A1 of the conductor layer 20. Since the conductor layer 20 in the power supply region A1 is thick, its electrical resistance is not high, and sufficient current can flow. In addition, the portion of the conductor layer 20 that is in contact with the electrode terminals is less likely to become high voltage, making it less likely for current supply abnormalities such as dissolution or abnormal deposition of the conductor layer 20 to occur.

[0027] From the viewpoint of suppressing abnormal current supply in the conductor layer 20, it is preferable that the conductor layer 20 in the power supply region A1 is thicker. Specifically, the average thickness of the conductor layer 20 in the power supply region A1 is preferably 0.5 μm or more, more preferably 0.6 μm or more, and even more preferably 1.0 μm or more. However, from the viewpoint of suppressing abnormal current supply in the conductor layer 20, there is no upper limit to the average thickness of the conductor layer 20. However, the average thickness of the conductor layer 20 of the copper-clad laminate 1 processed by the semi-additive method is generally 5 μm or less.

[0028] In step (4), unnecessary portions of the conductor layer 20 are removed by etching. Since the conductor layer 20 in the wiring formation region A2 is thin, the etching time can be shortened, and the etching progress of the wiring portion can be reduced. Therefore, it is easy to make the cross-sectional shape of the wiring rectangular.

[0029] From the viewpoint of making the cross-sectional shape of the wiring rectangular, it is preferable that the conductor layer 20 in the wiring formation region A2 be as thin as possible. Specifically, the average thickness of the conductor layer 20 in the wiring formation region A2 is preferably 0.5 μm or less (or less than 0.5 μm), more preferably 0.4 μm or less, and even more preferably 0.2 μm or less.

[0030] The thickness of the conductive layer 20 can be measured using an X-ray fluorescence film thickness gauge. The conductive layer 20, particularly the copper plating film 22, inevitably exhibits variations in thickness due to current concentration and uneven current density during electrolytic plating. The "average thickness" of the conductive layer 20 refers to the average value of the thickness measured at predetermined intervals using an X-ray fluorescence film thickness gauge.

[0031] The range of variation in the thickness of the conductor layer 20 in the power supply region A1 (range from maximum to minimum value) is preferably ±20% or less of the average thickness, more preferably ±15% or less, and even more preferably ±10% or less. Similarly, the range of variation in the thickness of the conductor layer 20 in the wiring formation region A2 is preferably ±20% or less of the average thickness, more preferably ±15% or less, and even more preferably ±10% or less.

[0032] (Other embodiments) The conductor layer 20 may be formed on only one side of the base film 10, as shown in Figure 2(B), or on both sides of the base film 10, as shown in Figure 4(A). By processing the copper-clad laminate 2, on which the conductor layer 20 is formed on both sides of the base film 10, a flexible printed circuit board with wiring patterns formed on both sides can be obtained.

[0033] As shown in Figure 2(B), if a thicker conductive layer 20 power supply region A1 is provided on both edges of the copper-clad laminate 1, the electrode terminals of the electroplated material can be connected to both power supply regions A1. This makes it easier to make the current density of the wiring formation region A2 uniform. On the other hand, as shown in Figure 4(B), a thicker conductive layer 20 power supply region A1 may be provided on only one edge of the copper-clad laminate 3. This would widen the wiring formation region A2.

[0034] As shown in Figure 4(C), a conductive layer 20 having a power supply region A1 on only one edge may be formed on both sides of the base film 10.

[0035] [Method for manufacturing copper-clad laminates] Next, the manufacturing method of the copper-clad laminate 1 will be explained based on Figure 5. The manufacturing method of this embodiment includes an electroplating step and a cutting step. After obtaining an intermediate copper-clad laminate 1i in the electroplating step, the final copper-clad laminate 1f is obtained in the cutting step. In this specification, the final copper-clad laminate 1f is synonymous with copper-clad laminate 1.

[0036] Using a roll-to-roll sputtering apparatus, a metal layer 21 can be formed on the surface of a long, strip-shaped base film 10. Hereinafter, the base film 10 with the metal layer 21 formed on its surface will be referred to as the substrate 11.

[0037] (1) Electrolytic plating process By using a roll-to-roll plating apparatus, a copper plating film 22 can be formed on the surface of a long, strip-shaped substrate 11. This yields a long, strip-shaped copper-clad laminate intermediate product 1i.

[0038] The plating apparatus is a device that performs electroplating on a long, strip-shaped substrate 11 while transporting it using a roll-to-roll mechanism. The plating apparatus has a supply device that unwinds the substrate 11 wound in a roll shape, and a winding device that winds the plated substrate 11 (intermediate copper-clad laminate 1i) back into a roll shape. A pre-treatment tank, a plating tank, and a post-treatment tank are arranged in the transport path between the supply device and the winding device. As the substrate 11 is transported through the plating tank, a copper plating film 22 is formed on its surface by electroplating.

[0039] The plating tank contains a copper plating solution. The copper plating solution contains a water-soluble copper salt. Any water-soluble copper salt commonly used in copper plating solutions can be used without particular limitation. The copper plating solution may also contain sulfuric acid. The pH and sulfate ion concentration of the copper plating solution can be adjusted by adjusting the amount of sulfuric acid added. The copper plating solution may also contain additives commonly added to plating solutions. As additives, one type selected from brightener components, leveler components, polymer components, chlorine components, etc., may be used alone, or two or more types may be used in combination.

[0040] The substrate 11 being transported inside the plating tank is immersed in a copper plating solution. An anode 41 is also positioned inside the plating tank so as to face the main surface of the substrate 11. By using the substrate 11 as a cathode and passing an electric current between it and the anode 41, a copper plating film 22 can be formed on the surface of the substrate 11.

[0041] A shielding plate 42 is placed between the substrate 11 and the anode 41. The shielding plate 42 is an insulating plate. The material of the shielding plate 42 is not particularly limited, but resins, ceramics, etc., that are insulating and resistant to erosion by the copper plating solution are preferred. A perforated board having multiple holes that penetrate both sides can be used as the shielding plate 42. Because current leaks through the holes in the shielding plate 42, the shielding plate 42 does not completely shield the current, but shields it to a moderate degree. Therefore, the copper plating film 22 can be formed even in the area of ​​the substrate 11 facing the shielding plate 42.

[0042] In this embodiment, the shielding plate 42 is narrower than the base material 11 and is positioned in the center in the TD direction (left-right direction in Figure 5). Because the shielding plate 42 shields the current in the central region, the current density in the central region of the base material 11 is lower than the current density in the left and right edge regions. As a result, the copper plating film 22 becomes thinner in the central region and thicker in the edge regions.

[0043] In areas where the copper plating film 22 is deposited thickly, the conductive layer 20, when combined with the metal layer 21, is also thick. In areas where the copper plating film 22 is deposited thinly, the conductive layer 20, when combined with the metal layer 21, is also thin. Hereinafter, areas where the conductive layer 20 is thick will be referred to as thick-film regions A3, and areas where the conductive layer 20 is thin will be referred to as thin-film regions A4.

[0044] The thick-film region A3 and the thin-film region A4 are both strip-shaped regions along the MD direction of the copper-clad laminate intermediate product 1i. The copper-clad laminate intermediate product 1i in this embodiment has two thick-film regions A3 at both the left and right ends. The thin-film region A4 is positioned between the two thick-film regions A3.

[0045] As described later, after cutting the copper-clad laminate intermediate product 1i in the cutting process, the thick-film region A3 becomes the power supply region A1, and the thin-film region A4 becomes the wiring formation region A2. Therefore, the thickness of the conductor layer 20 in the thick-film region A3 is set to match the power supply region A1. Also, the thickness of the conductor layer 20 in the thin-film region A4 is set to match the wiring formation region A2. That is, the average thickness of the conductor layer 20 in the thick-film region A3 is preferably 0.5 μm or more, more preferably 0.6 μm or more, and even more preferably 1.0 μm or more. The average thickness of the conductor layer 20 in the thin-film region A4 is preferably 0.5 μm or less (or less than 0.5 μm), more preferably 0.4 μm or less, and even more preferably 0.2 μm or less.

[0046] The thickness of the copper plating film 22 can be adjusted by the current density and plating time in electroplating. Furthermore, the difference in thickness of the copper plating film 22 between the thin film region A4 and the thick film region A3 depends on the current shielding force of the shielding plate 42. The current shielding force of the shielding plate 42 can be adjusted, for example, by the porosity ratio. Here, the porosity ratio means the ratio of the total area of ​​holes to the area of ​​the main surface of the shielding plate 42. The higher the porosity ratio, the weaker the current shielding force can be. The lower the porosity ratio, the stronger the current shielding force can be.

[0047] The width dimensions and positions of the thin-film region A4 and the thick-film region A3 depend on the width dimensions and positions of the shielding plate 42. Increasing the width of the shielding plate 42 increases the width of the thin-film region A4, and decreasing the width of the shielding plate 42 decreases the width of the thin-film region A4. The position of the shielding plate 42 can be adjusted to control the position of the thin-film region A4.

[0048] (2) Cutting process Next, the copper-clad laminate intermediate product 1i is cut longitudinally using a slitter. In this embodiment, the copper-clad laminate intermediate product 1i is cut at a specific position in the thick film region A3 (the position indicated by the dashed line in Figure 5). This removes the end portion of the copper-clad laminate intermediate product 1i.

[0049] (3) Copper-clad laminated board final product Cutting the intermediate copper-clad laminate 1i yields the final copper-clad laminate 1f. The final copper-clad laminate 1f has a power supply region A1 with a thick conductor layer 20 and a wiring formation region A2 with a thin conductor layer 20. The remaining portion of the thick film region A3 of the intermediate copper-clad laminate 1i becomes the power supply region A1 of the final copper-clad laminate 1f. The thin film region A4 of the intermediate copper-clad laminate 1i becomes the wiring formation region A2 of the final copper-clad laminate 1f. In this embodiment, the end of the intermediate copper-clad laminate 1i is removed, and the final copper-clad laminate 1f is obtained in which the width dimension of the power supply region A1 is adjusted to a predetermined width.

[0050] Furthermore, in the electroplating process, if anodes 41 are placed on both the front and back surfaces of the substrate 11, a copper plating film 22 can be formed on both surfaces of the substrate 11. In this case, shielding plates 42 are also placed on both the front and back surfaces of the substrate 11. This results in the copper-clad laminate 2 shown in Figure 4(A).

[0051] Alternatively, one thick film region A3 of the copper-clad laminate intermediate product 1i may be cut at its midpoint, and the entirety of the other thick film region A3 (and the intermediate region) may be removed. In this way, copper-clad laminates 3 and 4 shown in Figure 4(B) or Figure 4(C) can be obtained.

[0052] (Other embodiments) As shown in Figure 6, in the electroplating process, multiple shielding plates 42 may be arranged in the TD direction between the substrate 11 and the anode 41. Gaps are left between adjacent shielding plates 42. The region opposite this gap also becomes a thick film region A3. Therefore, a conductive layer 20 having three or more thick film regions A3 can be formed. In the illustrated example, two shielding plates 42 are arranged in the TD direction. A conductive layer 20 can be formed having three thick film regions A3 at both ends and in the center, and two thin film regions A4 in between them.

[0053] This copper-clad laminate intermediate product 1i is cut at specific locations in each thick-film region A3. This yields multiple (two in the illustrated example) copper-clad laminate final products 1f.

[0054] If the width of the central thick-film region A3 is large, the central thick-film region A3 can be cut in two places and the portion in between can be removed. This will allow the width of the power supply region A1 of the final copper-clad laminate product 1f to be adjusted to the specified width. [Examples]

[0055] (Common conditions) A long, strip-shaped polyimide film (Upilex, manufactured by Ube Industries, Ltd.) with a width of 570 mm and a thickness of 34 μm was prepared as the base film. The base film was set in a magnetron sputtering apparatus. A nickel-chromium alloy target and a copper target were installed inside the magnetron sputtering apparatus. The nickel-chromium alloy target was composed of 20 mass% Cr and 80 mass% Ni. Under a vacuum atmosphere, a 25 nm thick underlayer metal layer made of nickel-chromium alloy was formed on both sides of the base film, and a 100 nm thick copper thin film layer was formed on top of it.

[0056] A copper-plated laminate intermediate was obtained by depositing copper plating films on both sides of a substrate using a roll-to-roll plating apparatus. The copper plating solution stored in the plating tank contained 120 g / L of copper sulfate, 70 g / L of sulfuric acid, 16 mg / L of a brightener component, 20 mg / L of a leveler component, 1,100 mg / L of a polymer component, and 50 mg / L of a chlorine component. Bis(3-sulfopropyl) disulfide (reagent manufactured by RASCHIG GmbH) was used as the brightener component. Diallyldimethylammonium chloride-sulfur dioxide copolymer (PAS-A-5 manufactured by Nitto Boseki Medical Co., Ltd.) was used as the leveler component. Polyethylene glycol-polypropylene glycol copolymer (Unilube 50MB-11 manufactured by NOF Corporation) was used as the polymer component. Hydrochloric acid (35% hydrochloric acid manufactured by Wako Pure Chemical Industries, Ltd.) was used as the chlorine component.

[0057] (Examples 1-3) In electroplating, a shielding plate was placed between the center of the substrate and the anode, so that the copper plating film in the central region of the substrate in the TD direction, with a width of approximately 480 mm, was thinner than the copper plating film in both end regions. By varying the current density, plating time, and the porosity of the shielding plate during electroplating, three types of intermediate copper-clad laminates with different thicknesses of the conductor layer in the central and end regions were manufactured.

[0058] The thickness of the conductive layer was measured using an X-ray fluorescence thickness gauge (SFT9250, manufactured by SII Nanotechnology Co., Ltd.). The collimator was set to a diameter of 0.5 mm, and the measurement time for each measurement point was set to 30 seconds per point. The thickness was measured at 1 mm intervals along the TD direction of the intermediate copper-clad laminate, and the average thickness of the central and edge regions was determined. The thickness of the conductive layer is shown in Table 1.

[0059] (Comparative Example 1) In electroplating, a copper plating film was formed without placing a shielding plate between the substrate and the anode, obtaining an intermediate copper-clad laminate. That is, no difference in thickness was created between the central and edge regions. The thickness of the conductor layer is shown in Table 1.

[0060] (Comparative Example 2) In electroplating, shielding plates were placed between both ends of the substrate and the anode, so that the copper plating film in the central region of the substrate in the TD direction, approximately 480 mm wide, was thicker than the copper plating film in both end regions. The thickness of the conductor layer is shown in Table 1.

[0061] The ends of the intermediate copper-clad laminates obtained in Examples 1-3 and Comparative Examples 1 and 2 were cut off with a slitter to obtain final copper-clad laminates with a width of 500 mm.

[0062] Five types of finished copper-clad laminates were processed using the following procedure. A resist layer was formed on both sides of the finished copper-clad laminate. Here, the resist layer was formed in the central region (approximately 480 mm wide) of the finished copper-clad laminate, leaving the conductor layer exposed in both end regions (approximately 10 mm wide). An opening was formed in the resist layer in the area where the wiring pattern would be formed. Clip-type plated electrode terminals were attached to both end regions of the finished copper-clad laminate, and the wiring pattern was formed by applying current in a copper sulfate plating bath for 30 minutes. Here, the current density was 1 A / dm². 2 and 3A / dm 2 The wiring pattern was formed under these two conditions.

[0063] The area near the electrode terminals of the copper-clad laminate with the wiring pattern was observed to evaluate whether there were any abnormalities in the current supply of the conductor layer. The results are shown in Table 1.

[0064] [Table 1]

[0065] Table 1 shows that the thicker the conductor layer in the end region where the electrode terminals of electroplating are connected, the less likely current supply abnormalities are to occur in the conductor layer. When the average thickness of the conductor layer in the end region is 1.0 μm or 0.6 μm (Examples 1 and 2), the current density in electroplating is 3 A / dm 2 Even so, no dissolution or abnormal deposition of the conductor layer was observed. When the average thickness of the conductor layer in the edge region is 0.5 μm (Example 3), the current density in electroplating is 3 A / dm 2 In that case, the conductive layer will dissolve slightly, but the current density will be 1 A / dm 2 Therefore, dissolution and abnormal deposition of the conductor layer are not observed. When the average thickness of the conductor layer in the edge region is 0.2 μm (Comparative Examples 1 and 2), the current density is 1 A / dm 2 However, this can lead to dissolution or abnormal deposition of the conductive layer.

[0066] From this, it was confirmed that in order to suppress abnormal current supply in the conductor layer, it is preferable to set the average thickness of the edge region of the copper-clad laminate to 0.5 μm or more, more preferably to 0.6 μm or more, and even more preferably to 1.0 μm or more. [Explanation of symbols]

[0067] 1 Copper-clad laminate 10 base film 20 Conductor layer 21 Metal layer 21a Base metal layer 21b Copper thin film layer 22 Copper plating film A1 Power supply area A2 Wiring formation area

Claims

1. An electrolytic plating process to obtain a copper-clad laminate intermediate by electrolytic plating while conveying a substrate by roll-to-roll, The process includes a cutting step of cutting the intermediate copper-clad laminate with a slitter to obtain the final copper-clad laminate, In the electroplating process described above, a shielding plate is placed between the central region of the substrate in the TD direction and the anode to reduce the current density in a predetermined region of the substrate, thereby forming a conductive layer having a strip-shaped thick film region and a thin film region along the MD direction. In the cutting process, the copper-clad laminate intermediate is cut in the thick film region to form the copper-clad laminate final product, in which the power supply region, which is the region near the edge along the MD direction, has a conductor layer that is thicker than the wiring formation region, which is all or part of the other region. A method for manufacturing copper-clad laminates, characterized by the following:

2. In the electroplating step, a plurality of shielding plates are arranged in the TD direction between the substrate and the anode, and the conductive layer having a plurality of thick film regions is formed. A method for manufacturing a copper-clad laminate according to claim 1.

3. The shielding plate has a plurality of holes that penetrate through the front and back sides. A method for manufacturing a copper-clad laminate according to claim 1.

4. The conductor layer has an average thickness of 0.5 μm or more in the power supply region and an average thickness of less than 0.5 μm in the wiring formation region. A method for manufacturing a copper-clad laminate according to claim 1.

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