JP2013181180A - Pretreatment method for electroplating, and method of producing copper clad laminated resin film by electroplating method including the pretreatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of depositing an electroplated film reduced in fine surface defect on a long-length conductive substrate conveyed roll to roll.SOLUTION: A pretreatment method performed before continuously performing electroplating on a long-length film F with a thin film as a long-length conductive substrate conveyed by a roll to roll system by immersing it in an electroplating bath 21 includes the process of immersing the long-length film F with the thin film in a cleaning bath filled with a chemical liquid 53 such as, for example, sulfuric acid or the like as a cleaning solution and the process of nipping the long-length film F with the thin film by one pair of ringer rolls 55 of 70-90° in surface hardness directly after immersing it in the cleaning bath.

Description

  The present invention relates to a pretreatment method for electroplating applied to a long conductive substrate conveyed by roll-to-roll, and an electroplating method including the pretreatment method, and further to an electroplating method including the pretreatment method. The present invention relates to a method for producing a copper-clad laminated resin film.

  Electroplating is widely used in industry, including semiconductor circuit formation, surface treatment of steel strips and copper foils, production of electrolytic copper foils, and production of copper-clad laminated resin films. Among them, the copper-clad laminated resin film formed by forming a copper electroplated film on the surface of a resin film such as polyimide is used as a base material for flexible wiring boards, as well as small electronic devices such as mobile phones, and liquid crystal displays. Such devices are often used in COF (Chip On Film) mounting in driver circuits of display devices.

  In the production of a flexible wiring board, conventionally, a three-layer copper-clad laminated resin film in which an adhesive is interposed between a polyimide film, which is a kind of resin film, and a copper foil and these are laminated and bonded together is used. And a flexible wiring board is manufactured by pattern-forming by this subtractive method etc. in this 3 layer copper clad laminated resin film.

  The wiring pitch (distance between the centers of adjacent wirings) of the flexible wiring board used in the COF mounting is mainly 40 to 50 μm before 2005. However, in recent years, fine wiring processing has progressed as electronic components become lighter, thinner, and smaller, and the wiring pitch is becoming mainstream of 30 μm or less. Thus, in recent years, the demand for narrowing the pitch of the wiring of the flexible wiring board has increased.

  Therefore, it is becoming a requirement that the copper-clad laminated resin film used as the substrate can draw fine wiring, and as a result, the demand for a two-layer copper-clad laminated resin film without an adhesive layer is increasing. The reason why the demand for the two-layer copper-clad laminated resin film is increased is that the adverse effect is eliminated by omitting the adhesive layer, so that a stable base material utilizing the original characteristics of polyimide can be obtained.

  As a method for producing such a two-layer copper-clad laminated resin film, for example, in Patent Document 1, a metal layer is directly laminated on the surface of a polyimide film by a sputtering method, and then a metal layer is formed using an electroplating method or an electroless plating method. A so-called metalizing method has been proposed for thickening. And it is shown that the two-layer copper-clad laminated resin film produced in this way is adopted for COF mounting.

  That is, as a method for producing a two-layer copper-clad laminated resin film in which a metal layer is formed on the surface of a polyimide film, which is a resin film, generally, nickel, chromium, nickel-chromium alloy is first formed on the surface of the polyimide film by sputtering. In order to form a base metal layer made of, for example, and provide good conductivity thereon, a copper thin film layer is formed by a plating method to obtain a metal thin film. And in order to form the thick conductive layer for circuit formation, a copper plating film layer is formed by the electroplating method or the combined use of the electroplating method and the electroless plating method.

  When the metal conductive layer is formed by the electroplating method, for example, an electroplating film is continuously formed using a continuous plating apparatus as disclosed in Patent Document 2, for example. This continuous plating apparatus is composed of a plurality of electroplating tanks arranged along the conveying direction of the film-like substrate that is the material to be plated, and an electroplating solution is supplied into each electroplating tank and the cathode An anode is installed at a position facing the electroplating surface of the film-like substrate that plays a role.

  Furthermore, each electroplating tank is provided with a power supply unit for supplying electric power and a transport mechanism for continuously transporting the film-like substrate. With this configuration, the film-like substrate is immersed in the electroplating solution while being continuously conveyed, whereby electricity flows between the film-like substrate and the anode, and the metal conductive layer is formed on the metal thin film surface of the film-like substrate. Are stacked.

  In addition, since the quality of the electroplating film can be improved by pretreatment before electroplating, the surface of the material to be plated is washed beforehand with a chemical solution such as an acid when electroplating is performed. Preprocessing is widely performed. For example, Patent Document 3 discloses that before introducing a long plastic film into a plating bath, the film is subjected to pretreatment such as acid treatment, degreasing treatment, and water washing treatment.

JP 2002-252257 A JP 2009-026990 A JP 2007-246962 A

  However, in the pretreatment method as described above, it is difficult to obtain an electroplated film with few fine surface defects in COF mounting or the like where a fine wiring pattern is desired. The present invention has been made in view of such a situation, and performs an appropriate pretreatment on a long conductive substrate conveyed by roll-to-roll in order to continuously perform electroplating, and thereby the fine surface defects are eliminated. It aims at providing the method of obtaining few electroplating films. Furthermore, it aims at providing the manufacturing method of the copper clad laminated resin film in which the pitch reduction required in COF mounting is possible by the metalizing method which applied this method.

  In order to solve the above problems, the present inventors form a metal layer such as Ni, Cr, Cu or the like on the polyimide film surface by vapor deposition or sputtering, and then thicken copper by electroplating or electroless plating. As a result of diligent research on a manufacturing method that reduces the number of surface defects in the metal layer of the metallized polyimide film substrate produced by this method, the surface of the film substrate is contacted in the pretreatment step before the plating step. It has been found that the hardness of the surface portion of the roller to be affected affects the surface defects of the copper film obtained after the plating step, and the present invention has been completed.

  That is, the pretreatment method for a long conductive substrate of the present invention is performed before continuous electroplating by immersing the long conductive substrate conveyed by a roll-to-roll method in an electroplating tank. A pretreatment method, a step of immersing a long conductive substrate in a cleaning tank filled with a cleaning liquid, and a pair of ringer rolls having a surface hardness of 70 ° to 90 ° immediately after being immersed in the cleaning tank And a step of sandwiching a long conductive substrate.

  Further, the electroplating method of the long conductive substrate of the present invention is a method of electroplating while transporting the long conductive substrate by a roll-to-roll method, and the electroconductive method is immersed in an electroplating bath. An electroplating step for electroplating the surface, and a pretreatment step performed before the electroplating step, wherein the pretreatment step is a step of immersing the long conductive substrate in a cleaning tank filled with a cleaning solution; And a step of sandwiching a long conductive substrate with a pair of ringer rolls having a surface hardness of 70 ° to 90 ° immediately after being immersed in the cleaning tank.

  According to the pretreatment method and electroplating method of the long conductive substrate of the present invention, a plating film with few fine surface defects can be obtained without scratching the long conductive substrate. Then, by applying these pretreatment methods and electroplating methods to a method for producing a copper-clad laminated resin film, a copper-clad laminated resin film suitable for COF mounting subjected to fine wiring processing can be obtained.

1 is a schematic front view of a continuous processing apparatus capable of performing an electroplating method including a pretreatment method according to an embodiment of the present invention. It is a typical front view which shows one specific example of the pre-processing unit contained in the continuous processing apparatus shown in FIG. It is a typical front view which shows the other specific example of the pre-processing unit contained in the continuous processing apparatus shown in FIG. It is general | schematic sectional drawing of the copper clad laminated resin film which can be produced with the electroplating method including the pre-processing method of this invention.

  Hereinafter, the case where a copper clad laminated resin film is produced by an electroplating method including a pretreatment method according to an embodiment of the present invention will be described with reference to the continuous treatment apparatus shown in FIG. The continuous processing apparatus shown in FIG. 1 was unwound with an unwinding roll 11 from which a long polyimide film with a metal thin film (hereinafter also referred to as a long film with a thin film) F as a long conductive substrate was unwound. A pretreatment unit 12 that is a device for pretreatment of the long film F with a thin film, an electroplating unit 13 that is a device for electroplating the long film with a thin film F that has been pretreated, and electroplating And a take-up roll 14 for winding the long film. In addition, the electroconductive metal thin film currently formed into a film on the surface of one side of this long film F with a thin film is previously formed by sputtering method.

  By processing the long film F with a thin film using such a continuous processing apparatus, a copper plating film layer having a film thickness is laminated on the surface of the one side of the long film F with a thin film without interposing an adhesive. Can do. In addition, what electroplated the long film F with a thin film here is called the copper covering long polyimide film or the copper clad laminated resin film (henceforth a copper covering long film) S.

[Electroplating unit]
First, the electroplating unit 13 will be specifically described. In the electroplating unit 13 of the continuous processing apparatus of FIG. 1, the electroplating can be continuously applied to the long film F with a thin film that is continuously conveyed by a general roll-to-roll method. . Specifically, the electroplating unit 13 is disposed inside the electroplating tank 21 having a substantially rectangular parallelepiped shape in which an acidic electroplating solution mainly containing sulfuric acid and copper sulfate is stored. Eight plate-like anodes (anodes) 22a to 22h and an electroplating tank 21 are disposed above, demarcating the transport path of the long film F with a thin film, and the conductivity of the long film F with a thin film. It is composed of five power supply rolls 23a to 23e for supplying power to the surface and four transport guide rolls 24a to 24d that are arranged inside the electroplating tank 21 and demarcate the transport path of the long film F with thin film. Has been.

  The eight plate-like anodes 22a to 22h are opposed to the long film F with a thin film that reciprocates in the vertical direction in the electroplating solution, with one anode facing each upward or downward traveling section. Are arranged in a row in the horizontal direction. Each of these eight anodes 22a to 22h constitutes an electrically independent electroplating cell together with the corresponding power supply roll and the long film F with a thin film facing each other. Thereby, it becomes possible to electroplate on the metal film of the long film F with a thin film for every electroplating cell.

  Specifically, the anodes 22a to 22h are respectively connected to positive electrodes of a plurality of control power supplies (also referred to as rectifiers) that are not electrically shown, and the negative electrodes of these control power supplies are in close proximity to the anodes. The power feed rolls 23a to 23e are respectively connected to the power feed rolls 23a to 23e. Thereby, the surface on the side where the metal film (conductive layer) is laminated in the long film F with a thin film is sequentially brought into contact with the five power supply rolls 23a to 23e, so that each anode and the long thin film with a thin film facing the anode are provided. A potential difference is generated between the film F and the metal film, and electroplating is performed on the metal film.

  For example, the anode 22a is an electroplating circuit including a power supply roll 23a, a control power source (not shown) connected to the anode 22a and the power supply roll 23a, and a portion of the long film F with a thin film facing the anode 22a. Is configured. The anode 22b is an electroplating circuit comprising a power supply roll 23b, a control power source (not shown) connected to the anode 22b and the power supply roll 23b, and a portion of the long film F with a thin film facing the anode 22b. Is configured. Similarly, the other anodes 22c, 22d, 22e, 22f, 22g, and 22h constitute an electroplating circuit.

  In the electroplating circuit of these eight anodes 22a to 22h, the current density is controlled by the control power source so as to increase stepwise from the unwinding roll 11 side toward the winding roll 14 side. In addition, the value of the current density in each electroplating circuit is appropriately determined in consideration of various plating conditions such as the thickness of the copper electroplating layer laminated in the electroplating circuit.

  Each anode may be a soluble anode or an insoluble anode. In the production of the copper clad laminated resin film, copper electroplating is performed for forming the copper coating layer. Therefore, when a soluble anode is used, a copper plate that is dissolved into the anode and becomes a source of copper ions can be used. On the other hand, when an insoluble anode is used, a metal anode such as platinum or lead, or a ceramic anode obtained by coating a titanium frame with a conductive ceramic such as iridium oxide, rhodium oxide, or ruthenium oxide. Can be used. In this case, the copper ion supply source is provided outside the electroplating tank.

  The electroplating unit 13 further includes a long film conveying device represented by a tension control roll for controlling the tension of the long film F with a thin film, and various known devices such as a plating solution supply device and a stirrer. Will be installed as needed.

  The electroplating process performed in the electroplating unit 13 described above will be described. The long film F with a thin film is unwound from the unwinding roll 11 in a state where the width direction thereof is substantially horizontal, and is a pretreatment process described later. After the pretreatment, power is supplied by the power supply roll 23 a located above the plating tank 21, and the conveying direction is changed downward in the vertical direction so as to be immersed in the plating solution in the plating tank 21. Since the anode 22a is disposed in the plating solution so as to face the surface on the metal thin film side of the soaked long film F with thin film, between the metal thin film of the long film with thin film F and the anode 22a. Electricity flows and electroplating is performed on the metal thin film.

  The long film F with a thin film is then plated toward the power supply roll 23b provided next to the power supply roll 23a, with the transport direction reversed by a transport guide roll 24a disposed at the bottom of the plating tank 21. Run vertically in liquid. Since the anode 22b is provided so as to face the surface on the metal thin film side of the long film F with a thin film traveling upward, electricity flows between the metal thin film of the long film F with a thin film and the anode 22b. Electroplating. Note that power is supplied from the power supply roll 23b to the long film F with a thin film traveling along the upward conveyance path.

  Thereafter, in the same manner, the long film F with a thin film traveling on the conveyance path from the power supply roll 23b to the guide roll 24b is electroplated by flowing electricity between the long film F and the anode 22c, and from the guide roll 24b to the power supply roll 23c. Electricity flows between the long film F with a thin film traveling on the conveyance path and the anode 22d and is electroplated, and the long film F with thin film traveling on the conveyance path from the power supply roll 23c to the guide roll 24c has an anode. An electric current flows between the anode 22f and the long film F with a thin film traveling on the conveying path from the guide roll 24c to the power feeding roll 23d. Electricity flows between the long film F with a thin film traveling on the transport path from the roll 23d to the guide roll 24d with the anode 22g. Is come, the thin film with elongated film F traveling on the conveyance path from the guide roll 24d to feed roll 23e is electroplated electricity flows between the anode 22h. In this way, the long film with thin film F is sequentially electroplated to form a copper-clad laminated resin film S, and is finally wound by the winding roll 14.

  In addition, the electroplating unit 13 which can implement suitably the electroplating method which concerns on this invention is not limited to the said structure. For example, the electroplating unit 13 is a method of electroplating while reciprocating the long film F with a thin film immersed in a plating solution in the vertical direction, but when electroplating the long film F with a thin film The direction is not limited to vertical, and electroplating may be performed while running in the plating solution in an oblique direction or a horizontal direction.

[Preprocessing unit]
Next, the preprocessing unit will be described. Generally, foreign substances such as organic substances and metal oxides constituting a metal thin film previously laminated on the surface exist on the surface of the base material before electroplating. Unless such foreign matter is properly removed, a plating film with few fine surface defects cannot be obtained. That is, when electroplating a substrate, it is desirable that no foreign matter exists on the surface of the substrate. Therefore, in the present invention, pretreatment is performed prior to the electroplating step. In the pretreatment, it is preferable to perform the chemical treatment process, the water washing process, and the dehydration / drying process in this order. Hereinafter, these steps will be described with reference to FIG.

  The pretreatment unit 12 shown in FIG. 2 includes a chemical solution processing unit 50, a water washing unit 60, a dehydrating unit 70, and a drying unit 80. In the chemical treatment unit 50, the film-like metal oxide existing on the metal thin film lamination surface side of the long film F with a thin film is immersed in a chemical solution containing an acid such as sulfuric acid. Removal is performed. Specifically, first, the long film F with a thin film is guided into the chemical treatment chamber 51 by a pair of pinch rolls 52 provided in the chemical treatment chamber 51. The surface portions of the pair of pinch rolls 52 are preferably formed of a flexible material such as rubber, so that the surface of the long film F with a thin film can be transported without scratching. it can.

  A chemical solution 53 is stored in the chemical solution processing chamber 51, and a reversing roll 54 that reverses the transport direction of the long film F with a thin film is provided in the chemical solution 53. A pair of ringer rolls 55 is provided above the liquid surface of the chemical liquid 53. With this configuration, the thin film with a thin film F is once immersed in the chemical solution 53 while traveling through a section from the pair of pinch rolls 52 to the pair of ringer rolls 55, and foreign matters such as metal oxides are removed. The And the long film F with a thin film which came out of the chemical | medical solution 53 is guide | induced to a pair of ringer roll 55. FIG.

  The pair of ringer rolls 55 are arranged in parallel to each other so as to sandwich the long film with thin film F from above and below, and each surface portion is formed of a flexible member such as rubber. Thereby, when passing the long film F with a thin film between one pair of ringer rolls 55, the chemical | medical solution adhering to the surface is squeezed out.

  Here, the hardness of the surface portion of the ringer roll 55 not only affects the efficiency when squeezing out the chemical solution adhering to the surface of the long film F with a thin film, but also affects the quality of the copper-coated long film S. It should be noted that That is, if the surface hardness of the ringer roll 55 is low, the surface of the thin film with a thin film F will not be scratched, but the amount of the processing liquid adhering to the surface increases, and a pinch described later on the downstream side of the transport path When the surface of the roll 62 or the like is contaminated and the contaminant is transferred to the metal thin film, micro unevenness may occur.

  On the other hand, if the surface hardness of the Ringer roll 55 is increased, the chemical solution can be removed at a higher removal rate, so that the fine irregularities can be reduced, but the surface of the Ringer roll 55 when transported by roll-to-roll. In this case, the long film F with a thin film may slip, which may cause a scratch on the metal thin film. The scratches on the surface of the thin film with a thin film F remain as scratches on the surface of the copper-clad laminated resin film S as the final product and cannot be used as a flexible wiring board.

  Therefore, in the present invention, the surface hardness of each of the pair of ringer rolls 55 is set to 70 ° to 90 °. Thereby, it is possible to prevent various problems as described above. The surface hardness is defined by JIS K 6253, and can generally be measured by a durometer. As a method of adjusting the surface hardness of the pair of ringer rolls 55 within the above range, a material such as rubber used for the surface part is appropriately selected, and the surface part of the pair of ringer rolls 55 is, for example, Teflon (registered trademark). It is also possible to coat with a fluororesin film such as

  In this way, in the chemical treatment process, mainly the metal oxide existing on the surface of the metal thin film of the long film F with a thin film is dissolved and removed in the chemical, so the chemical with the removed metal oxide dissolved therein. By appropriately squeezing and removing with a ringer roll, contamination of the roll surface on the downstream side of the conveyance path can be prevented. As a result, it is possible to prevent the problem that the contaminants are transferred from the downstream roll surface to the metal thin film to cause minute unevenness. In the above description, sulfuric acid is used as an example of the chemical solution in the chemical treatment process, but other chemical solutions can be appropriately selected according to the material of the long conductive substrate.

  The thin film-attached long film F processed by the chemical solution processing unit 50 is then sent to the water washing unit 60. In the washing unit 60, the long film F with a thin film treated in the chemical solution treatment process by the pair of pinch rolls 62 is guided into the washing chamber 61. The surface portions of the pair of pinch rolls 62 are also preferably formed of a flexible material such as rubber, like the pair of pinch rolls 52 of the chemical solution processing unit 50 described above. Thereby, it can convey, without damaging the surface of the long film F with a thin film.

  In the rinsing chamber 61, the long film F with thin film is washed with a known method such as rinsing with a pair of showers 63. Thereby, the chemical | medical solution which remains on the surface of the long film F with a thin film in a chemical | medical solution processing process is removed. The water used for washing is preferably water containing no impurities, and ultrapure water is particularly preferred. A pair of ringer rolls 64 is disposed in the water washing chamber 61, and the thin film-attached long film F that has been washed is thereby sandwiched and the water adhering to the surface is squeezed out. The pair of ringer rolls 64 preferably have a surface hardness of 70 ° to 90 °, similarly to the pair of ringer rolls 55 of the chemical solution processing unit 50 described above.

  The thin film-attached long film F that has been subjected to the water washing treatment in the water washing unit 60 is then sent to the dehydration unit 70. The dewatering unit 70 is provided with a pair of air knives 71 through which the long film F with a thin film passes. Each air knife is attached to be inclined with respect to the film surface so that the air outlet faces the slightly upstream side of the transport path of the long film F with a thin film. Water attached to the water is blown away with air.

  The thin film-attached long film F from which moisture has been removed by the air knife 71 is then sent to the drying unit 80. In the drying unit 80, a general drying process such as heat drying with dry air is performed in the drying chamber 81. Thereby, the water | moisture content adhering to the elongate film F with a thin film is dried.

  The pretreatment method of the present invention has been described above with reference to FIG. 2, but the pretreatment method of the present invention is not limited to the method described above. For example, as shown in FIG. 3, you may perform a pre-water-washing process and a degreasing process in this order before the chemical | medical solution processing process demonstrated above. That is, the pretreatment unit 120 shown in FIG. 3 includes a pre-water washing unit 30, a degreasing unit 40, a chemical solution processing unit 50, a water washing unit 60, a dehydrating unit 70, and a drying unit 80.

  More specifically, in the pre-rinsing section 30, the long film F with a thin film is washed with a pair of showers 32 provided in the pre-washing chamber 31, and then the thin film is attached with a pair of ringer rolls 33. Moisture adhering to the long film F with a thin film is squeezed out by sandwiching the long film F from above and below. The pair of ringer rolls 33 desirably have a surface hardness of 70 ° to 90 °, like the ringer roll 64 of the water washing section 60 described above.

  The thin film-attached long film F washed with the pre-washing unit 30 is then sent to the degreasing unit 40. By the way, as described above, the thin film with a thin film F is formed with a metal thin film in advance by a sputtering method, and is naturally degreased before the sputtering step. However, in a roll-to-roll type sputtering apparatus, organic substances may adhere to the surface of the long film F with a thin film in the process of winding up after sputtering film formation, visual inspection, and the like. The degreasing unit 40 removes this organic matter.

  In addition, the polyimide film which is a base material of the long film F with a thin film is processed by casting a polyamic acid and performing imidization by heating or stretching. Therefore, oligomers and machine oils may adhere to the surface of the polyimide film. Also from this point, it is desirable to degrease the long film F with a thin film in the pretreatment of electroplating.

  In the degreasing unit 40, the long film F with a thin film is immersed in the electrolytic degreasing liquid 42 stored in the electrolytic degreasing chamber 41 using the transport roll 43 and the reverse roll 44, and the electrolytic degreasing liquid 42 is electrolyzed. . Since organic substances can be removed by hydrogen and oxygen generated by this electrolysis, the long film F with a thin film can be degreased. A pair of ringer rolls 45 is disposed above the surface of the electrolytic degreasing liquid 42 and in the vicinity of the outlet of the electrolytic degreasing chamber 41, whereby the electrolytic degreasing liquid attached to the long film F with a thin film is removed. .

  The degreasing treatment is not limited to electrolytic degreasing, and may be a method of degreasing by immersing the long film F with a thin film in a degreasing liquid such as an organic solvent or an alkaline aqueous solution, or using ultrasonic waves in combination. Also good. These degreasing methods are preferably appropriately selected according to the material of the long conductive substrate. It is desirable that the surface hardness of the pair of ringer rolls 45 of the degreasing portion 40 is also set to 70 ° to 90 °.

  The thin film-attached long film F degreased by the electrolytic degreasing unit 40 is subsequently sent to the chemical solution processing unit 50, the water washing unit 60, the dehydrating unit 70, and the drying unit 80 to remove metal oxides and the like by immersion in the chemical solution. Then, washing with a shower or the like, dehydration with an air knife, and drying with dry air are performed. Since these processes are the same as those of the preprocessing unit 12 described above, detailed description thereof is omitted.

  A copper-clad laminated resin film S as shown in FIG. 4 is obtained by the pretreatment and electroplating described above. That is, in the manufacturing method of the copper clad laminated resin film according to the above-described embodiment of the present invention, the base metal layer 2a such as nickel, nickel-based alloy or chromium is first formed on the surface of the polyimide film 1 by the sputtering method. The thickness of the base metal layer 2a is not particularly limited, but is generally 5 to 50 nm.

  Examples of the nickel-based alloy that can be used for the base metal layer 2a include known nickel alloys such as a nickel-chromium alloy, a nickel-chromium-molybdenum alloy, and a nickel-vanadium-molybdenum alloy. However, the metal used for the base metal layer 2a needs to pay attention to the insulating property of the flexible wiring board and the etching property by the subtractive method.

  Subsequently, in order to give good conductivity to the surface of the base metal layer 2a, the copper thin film layer 2b is formed by a sputtering method of a dry plating method. Although the thickness of the copper thin film layer 2b formed by this process is not specifically limited, For example, it is 50-1000 nm, and 50 nm-500 nm are common from a viewpoint of productivity.

  Further, a copper thick film layer 3 made of a copper electrolytic plating layer is provided on the surface of the metal thin film layer 2 made of a laminate of the base metal layer 2a and the copper thin film layer 2b, that is, the surface of the copper thin film layer 2b. The copper thick film layer 3 has a desired film thickness by an electrolytic plating method which is a kind of wet plating method or a combination of an electroless plating method and an electrolytic plating method which are a kind of wet plating method. The film thickness of the copper thick film layer 3 formed on the surface of the metal thin film layer 2 is generally 5 to 18 μm, for example, when a circuit pattern is formed by a subtractive method.

  When the copper thick film layer 3 is formed by using both the electroless plating method and the electrolytic plating method, copper is formed on the surface of the metal thin film layer 2 by electroless plating, and then formed by electroless plating. Electrolytic plating is performed on the surface of the membrane.

  The pretreatment method and the electroplating method of the present invention have been described above by taking as an example a method for producing a copper-clad laminated resin film by performing copper electroplating on a long polyimide film with a metal thin film as a long conductive substrate. However, the present invention is not limited to this. For example, in addition to the above-mentioned long polyimide film with a metal thin film, a long copper foil, a strip of metal such as a steel strip can be used for the long conductive substrate. Moreover, this invention can be utilized for the pre-processing in the case of performing electroplating as surface treatment of the copper foil deposited by plating like electrolytic copper foil.

  As the long polyimide film, “Kapton (registered trademark) 150EN (thickness 38 μm)” manufactured by Toray DuPont Co., Ltd. having a width of 50 cm was used. This long polyimide film was subjected to heat treatment at 150 ° C. for 1 minute in a chamber maintained at a vacuum degree of 0.01 to 0.1 Pa.

  Subsequently, a base metal layer containing 20% by weight of chromium is formed on the long polyimide film by sputtering to a thickness of 20 nm, and a copper thin film layer is further formed to a thickness of 100 nm to form a long thin film with a metal thin film as a long conductive substrate. A polyimide film (long film F with a thin film) was obtained. A roll-to-roll type sputtering apparatus was used for sputtering. A copper clad laminated resin film S was produced on the long film F with a thin film using a continuous processing apparatus as shown in FIG.

  As the pretreatment unit 12, an apparatus including a chemical solution processing unit 50, a water washing unit 60, a dehydrating unit 70, and a drying unit 80 as shown in FIG. 2 was used. A 25 g / 1 liter sulfuric acid solution was used for the chemical solution 53 of the chemical solution processing unit 50. Ultrapure water was used as the water used for the pair of showers 63 in the water washing section 60. In the drying unit 80, the long film F with a thin film was dried with dry air at 40 ° C.

  In the electroplating unit 13, copper electroplating was performed. A soluble anode (phosphorus deoxygenated copper) was used as the anode. Further, a copper sulfate aqueous solution having a pH of 1 or less was used as the electroplating solution, and a predetermined amount of an organic additive was added thereto for the purpose of ensuring the smoothness of the copper plating film. The temperature of the electroplating solution was 27 ° C. The polyimide film F with a metal thin film was immersed in this electroplating solution to a depth of 1 m from the liquid surface. The current density of the electroplating apparatus is set so as to rise as the long film F with thin film is conveyed from the unwinding roll 11 side toward the winding roll 14 side, and a copper thick film layer is used as the copper electrolytic plating layer. It was formed with a thickness of 8 μm.

Example 1
The pretreatment unit 12 is subjected to pretreatment using a pair of ringer rolls 55 having a surface hardness of 70 °, followed by electroplating with the electroplating unit 13 to obtain a copper-clad laminate resin film S. Obtained. As a characteristic inspection, microscopic irregularities on the surface of the copper-clad laminated resin film S for 500 lots were observed with an optical microscope. As a result, a favorable result of 0.4 per 50 mm × 50 mm range was obtained.

(Example 2)
A copper-clad laminated resin film S was obtained in the same manner as in Example 1 except that a pair of ringer rolls 55 having a surface hardness of 90 ° was used for the chemical treatment unit 50 of the pretreatment unit 12. As a characteristic inspection, the micro unevenness on the surface of the copper-clad laminated resin film S was observed with an optical microscope.

(Comparative Example 1)
A copper-clad laminated resin film S was obtained in the same manner as in Example 1 except that the paired ringer roll 55 having a surface hardness of 50 ° was used for the chemical treatment unit 50 of the pretreatment unit 12. As a result of the characteristic inspection, the micro unevenness on the surface of the copper-clad laminated resin film S was measured. As a result, 1.0 (pieces / 50 mm mouth) per 50 mm × 50 mm range was insufficient.

(Comparative Example 2)
A copper-clad laminated resin film S was obtained in the same manner as in Example 1 except that a pair of ringer rolls 55 having a surface hardness of 100 ° was used for the chemical treatment unit 50 of the pretreatment unit 12. As a result of measuring the micro unevenness on the surface of the copper-clad laminated resin film S as a characteristic test, a good value of 0.4 pieces (pieces / 50 mm mouth) per 50 mm × 50 mm range was obtained. Since the surface of the long film F with a thin film was scratched by the slip of the long film F, the product could not be produced.

  In Examples 1 and 2, a copper-clad laminated resin film S suitable for fine wiring processing with a wiring pitch of 30 μm or less is obtained, in which the surface has a small unevenness of 50 mm × 50 mm and the wiring pitch is 30 μm or less. I was able to. On the other hand, in Comparative Example 1, it was confirmed that the surface of the copper-clad laminated resin film S has too many fine irregularities, and in Comparative Example 2, scratches occurred and there were defects.

F Long-length polyimide film with metal thin film S Copper clad laminated resin film 11 Unwinding roll 12 Pretreatment unit 13 Electroplating unit 14 Winding roll 30 Pre-water washing part 40 Degreasing part 50 Chemical solution treatment part 60 Water washing part 70 Dehydration part 80 Drying part 52, 62 One pair of pinch rolls 44, 54 Reversing rolls 32, 63 One pair of showers 71 One pair of air knives 33, 45, 55, 64 One pair of ringer rolls

Claims (5)

For a long conductive substrate conveyed by a roll-to-roll method, a pretreatment method that is performed before immersion in an electroplating bath and continuous electroplating,
A step of immersing the long conductive substrate in a cleaning tank filled with a cleaning solution, and a pair of ringer rolls having a surface hardness of 70 ° to 90 ° immediately after being immersed in the cleaning bath, A pretreatment method for a long conductive substrate, comprising a step of sandwiching. A method of electroplating while transporting a long conductive substrate in a roll-to-roll manner, wherein an electroplating step of immersing the electroconductive surface in an electroplating bath and electroplating the electroconductive surface; It consists of a pre-treatment process to be performed before,
The pretreatment step includes a step of immersing the long conductive substrate in a cleaning tank filled with a cleaning solution, and a pair of ringer rolls having a surface hardness of 70 ° to 90 ° immediately after being immersed in the cleaning bath. An electroplating method comprising: sandwiching a long conductive substrate.   The pretreatment step includes a step of washing the long conductive substrate with water after the step of sandwiching the long conductive substrate, and a drying step of drying water adhering to the long conductive substrate in the water washing step. The electroplating method according to claim 2, further comprising:   The electroplating method according to claim 2, wherein the electroplating step is a copper electroplating step.   The electroplating method according to any one of claims 2 to 4, with respect to the resin film with a metal thin film having a metal thin film layer laminated on at least one surface of the long resin film substrate without using an adhesive. A method for producing a copper-clad laminated resin film, comprising forming a copper layer.

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