JP2010069861A - Metallic foil with support and method for manufacturing the same, and flexible circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic foil with a support and a method for manufacturing the same which easily provide an ultra-thin metallic foil in spite of simple constitution and a simple method. <P>SOLUTION: An exfoliation layer comprising one or more among oxides of Cu, Al, Ni, Cr, Si and Ti, a metallic layer comprising one or more among electroconductive metals of Cu, Al, Ni, Cr and Ti and a metal plating layer comprising one or more among metals of Cu, Al, Ni, Cr and Ti are laminated in this order on a surface of a polymer resin film which is a base material and also serves as a support to obtain the metallic foil with the support. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metal foil with a support, a method for producing the same, and a flexible circuit board obtained by using the metal foil. Specifically, an ultrathin metal foil is laminated on the surface. The present invention relates to a laminate, a manufacturing method thereof, and a flexible circuit board obtained by using an extremely thin metal foil.

  A so-called printed wiring board is widely used as a wiring in an electronic machine instrument. This is a circuit wiring made of a conductor such as a copper foil on an insulating or imparted substrate. In the conventional printed wiring board, a conductor such as copper is disposed on the surface of the board using various methods such as plating. However, since the electronic printed circuit boards are limited in the light and thin electronic equipment, especially the electronic equipment called mobile devices, mobile devices, etc., these devices are replaced by flexible circuit boards. This is the current situation.

  That is, among printed boards, printed wiring boards called flexible circuit boards are used for products that need to be packed with many components even though they are required to be small in size. . Since this flexible circuit board is thin and flexible, it is easy to increase the degree of freedom when it is incorporated into devices, and is widely used for small electronic devices such as mobile phones and notebook personal computers. .

  As a method for obtaining such a flexible circuit board, for example, a conductor is laminated on the base material of the flexible circuit board by plating, and then only a necessary circuit portion is left and then removed by etching. However, in this case, there are cases where various harmful substances are used when plating is performed, and there is a possibility that it may be regarded as a method including a problem in recent years when environmental problems are questioned. Therefore, a transfer method may be used instead. Specifically, a metal foil with a support (copper foil) is attached to the surface of a polymer resin film such as a polyethylene terephthalate (PET) film that becomes a base material of a flexible circuit board, and the metal foil with a support ( By peeling the support from (copper foil), the conductor (copper foil) is laminated on the surface of the substrate in the same manner as plating. Then, unnecessary portions are removed by etching to complete the circuit.

  The metal foil itself such as copper foil used in this method is usually prepared by rolling, electroplating or the like. However, as lighter, thinner and smaller devices are required, the thickness of the flexible circuit board itself has been required to be as thin as possible. For this reason, the metal foil itself, which is a conductor, is required to be extremely thin. However, if the method such as rolling described above is used, there is a limit to reducing the thickness, but in order to obtain an extremely thin metal foil, the metal foil obtained by the method such as rolling is etched to the desired thickness. I finished it. However, when the metal foil is etched, the metal foil itself is easily damaged, and the above-described method causes a problem that the cost is increased and the manufacturing process is increased and complicated.

  Therefore, as an ultrathin metal foil used in such a manufacturing method, for example, Patent Document 1 discloses an invention related to an ultrathin copper foil with a support having a configuration of support / adhesive layer / aluminum / copper foil. Patent Document 2 discloses an invention relating to a composite foil with a resin having a configuration of support metal layer / organic release layer / ultra thin copper foil / organic insulating layer.

JP 2002-280689 A Patent Registration No. 3612594

  If it is the ultra-thin copper foil with a support described in Patent Document 1, it is possible to obtain an ultra-thin copper foil having a thickness of 2 μm or less. It can be said that it is a thickness to be obtained. However, with this ultra-thin copper foil with a support, even when an aluminum layer having a thickness of 20 μm or less is partially transferred when the copper foil is transferred, the copper foil remains attached to the copper foil. This is a problem because an etching operation for removing the aluminum layer is required after the transfer of the foil is completed. Furthermore, the etching operation may be performed completely and beautifully, but there is a possibility that a necessary copper foil portion may be accidentally damaged, which is a further problem. In particular, the smaller the width between circuits, called the pitch width, the higher the possibility of such damage.

  In addition, the copper foil described in Patent Document 2 is said to be obtained even with a thickness of 5 μm or less, and it can be said that it is a thickness that can sufficiently meet the above-described demand for lightness, thinness, and reduction. However, it is said that an organic release layer formed of a compound selected from the group consisting of a nitrogen-containing compound, a sulfur-containing compound and a carboxylic acid is necessary in a laminate produced to obtain such a copper foil. . That is, in order to obtain an ultrathin copper foil, it means that it is necessary to go through a process of once laminating an organic release layer, and if necessary, an extra work step for obtaining an ultrathin copper foil will increase. . Furthermore, in order to obtain this release layer, it is necessary to use a so-called organic material, which is not necessarily preferable from the viewpoint of the working environment, and is still a problem.

  Therefore, the present invention has been made in view of such problems, and the object thereof is easily an ultrathin metal foil regardless of a simple configuration and a simple method. It is providing the metal foil with a support body, and its manufacturing method.

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is characterized in that a release layer and a metal layer made of a conductive metal are formed on the surface of a polymer resin film that is a base material and serves as a support. And a metal foil with a support, wherein the release layer is an oxide of copper, aluminum, nickel, chromium, silicon, or titanium. Any one or more of the above, the metal layer is any one or more of copper, aluminum, nickel, chromium, or titanium, and the metal plating layer is made of copper, aluminum, nickel, chromium, or titanium It is due to any or a plurality, the total thickness of the metal layer and the metal plating layer is 10 μm or less, and the metal layer and the metal plating are made of the same metal, By a transfer method using a serial support coated metal film in forming a flexible circuit board, the pitch width of the flexible circuit is possible to form a flexible circuit board even 50μm or less, and wherein.

  The invention according to claim 2 of the present invention is a release layer laminating step in which a release layer is laminated on the surface of a polymer resin film which is a base material and a support, and the surface of the release layer has conductivity. A metal laminating step in which a metal layer is laminated as a metal layer, and a plating step in which metal plating is performed on the surface of the metal layer to form a metal plating layer, and the surface of the metal layer is oxidized after the metal laminating step. In the case, a method for producing a metal foil with a support, characterized in that an oxidation step of oxidizing the surface of the metal layer is performed before the plating step, wherein the release layer is made of copper, aluminum, nickel , One or more of chromium, silicon or titanium oxide, the metal is copper, aluminum, nickel, chromium, or titanium, or the metal plating is copper, The metal layer and the metal plating layer have a total thickness of 10 μm or less, and the metal layer and the metal plating are made of the same metal. When the flexible circuit board is formed by the transfer method using the metal foil with the support, the flexible circuit board can be formed even if the pitch width of the flexible circuit is 50 μm or less. And

  The invention relating to the flexible circuit board according to claim 3 of the present invention is the flexible circuit board comprising the metal foil with a support according to claim 1 or the metal foil with a support obtained by the production method according to claim 2. It is used as a metal foil for wiring processing.

  As described above, in the case of a metal foil with a support according to the present invention, conventionally, a structure of a base material / (resin) release layer / a metal layer (to be used for transfer) is used. Therefore, when this was transferred, a part of the release layer might remain on the surface of the metal layer, which was a problem. As in the present invention, the brittleness of the release layer was used to make the substrate / release layer / metal. With the structure of layer / ~, even if the release layer remains on the surface of the metal layer immediately after the transfer, it can be easily and beautifully removed, so that the transfer of the beautiful metal layer is possible as a result. Can be easily realized. Further, since the metal layer and the metal plating layer are made of the same metal, adjustment for making the desired thickness of the transfer target layer necessary can be easily performed. In other words, after the metal layer is first laminated, metal plating with the thickness necessary for adjusting the thickness can be added, so that even finer thickness adjustments can be made and the thickness can be easily controlled. It becomes.

  Embodiments of the present invention will be described below. The embodiment shown here is merely an example, and is not necessarily limited to this embodiment.

(Embodiment 1)
A metal foil with a support according to the present invention and a method for producing the same will be described as a first embodiment.

  The metal foil with a support according to the present embodiment is a base material and the surface of a polymer resin film to be a support, a release layer, a metal layer made of a conductive metal, and a metal plating layer made of metal plating Are stacked in this order.

  First, a polymer resin film that is a base material and a support, may be any well-known plastic film conventionally used as a base material for transfer foil, such as a polyethylene terephthalate (PET) film. In this form, a PET film is used. Similarly, the thickness is not particularly limited, but it can be said that it is preferably 12 μm or more and 100 μm or less. This is because, in the case where the metal foil with a support according to the present embodiment is used as a transfer foil as will be described later, the PET film is widely used as a support, and in the case of simply forming a laminate. Is also widely used as the base material, and is easy to handle, and its properties are already widely known. In addition, assuming that the thickness is used as a transfer foil, a transfer foil with good operability can be easily obtained if the thickness is within the above range.

  The member made of the polymer resin film is “a base material and a support” in the present embodiment, and this will be described. The metal foil with a support according to the present embodiment can use the metal layer and the metal plating layer portion as a transfer foil as will be described later, and such use is one of the objects of the present invention. It is. That is, when the metal layer and the metal plating layer portion are used as the transfer foil, the combined portion of the metal layer / metal plating layer becomes an ultrathin foil as described later. For example, it is extremely difficult or impossible to transport or use a metal layer / metal plating layer as an ultrathin foil alone because it is extremely thin and easily damaged. It is obvious. In other words, an ultrathin foil composed of a metal layer / metal plating layer is easily transported to a desired location without damaging it, and a member that supports it is necessary to be able to use it correctly for the desired location. That is “to become a support”. On the other hand, when laminating various laminates, the first basic member is naturally necessary, which means that it is “a base material”. That is, the PET film in the present embodiment is a base material until the lamination of the metal foil is completed, and becomes a support after the lamination of the metal foil is completed.

Next, the release layer laminated on the surface of the polymer resin film will be described.
The release layer in this embodiment may be made of any one or more of copper, aluminum, nickel, chromium, silicon or titanium oxide, and will be described later when the surface of the metal layer is oxidized. By performing an oxidation process for oxidizing the surface of the metal layer before metal plating, the surface of the release layer is oxidized. In this embodiment, the release layer is made of copper. The reason will be described later.

The lamination of the release layer will be described.
First, a copper layer as a base for the release layer is laminated on the surface of the PET film. Here, it is necessary that a sufficient interlayer adhesion force is generated between them. This is because, as described later, when the metal foil with a support according to the present embodiment is used as a transfer foil, if there is not sufficient adhesion between these layers, when the metal layer is about to be peeled off, It is because there is a possibility of peeling from the base film together.

  The method for laminating copper on the surface of the PET film may be a conventionally known method. For example, it may be a conventionally known method such as a sputtering method, a vacuum deposition method, or an ion plating method. Then, although it shall be based on sputtering method, it will refuse that it is not limited to this.

  Next, the surface of the copper thus laminated on the surface of the PET film is further oxidized. Various methods can be considered for this oxidation method, and the surface may be oxidized by a conventionally known method, but the simplest and most effective oxidation method is opening to the atmosphere.

  That is, after laminating copper as a copper layer on the surface of the PET film by the sputtering method as described above, for example, a PET film in a state where the copper is laminated is taken out from the apparatus once performing the sputtering method, or a series of operations described later. After the step of laminating copper on the PET film surface, the surface of the copper layer is subsequently exposed to the atmosphere or exposed to an atmosphere equivalent to the atmosphere, and the surface of the copper layer is oxidized by a conventionally known method. .

  The thickness of the copper layer when laminating the copper layer on the surface of the PET film is preferably from 100 to 500 mm. If this is less than 100 mm, even if the surface is oxidized after the copper layer is laminated, it does not become a film, but only a so-called island-like structure. Therefore, the structure is inappropriate in this embodiment. This is not preferable. On the other hand, if it is 500 mm or more, there is a high possibility that the flexibility or flexibility of the entire metal foil with a support according to the present embodiment is not sufficient, which is not preferable.

  In the metal foil with a support according to the present embodiment, copper is laminated on the surface of the PET film as described above, and then the surface is oxidized to form a release layer, that is, a surface copper oxide layer. It is also possible to stack a material that is oxidized from, for example, silicon oxide.

Next, the metal layer laminated | stacked on the surface of this peeling layer (surface copper oxide layer) is demonstrated.
The metal layer according to the present embodiment may be any one or more of copper, aluminum, nickel, chromium, or titanium, but the important point is that suitable conductivity is obtained even when the metal layer is formed into a thin film. It is provided. In this embodiment, the metal layer is copper. The reason will be described later.

  The metal layer (copper layer) is formed on the surface of the release layer (surface copper oxide layer) by sputtering, vacuum evaporation, or ion, in the same manner as a release layer (surface copper oxide layer) is laminated on the surface of the base film. They are laminated by a conventionally known method such as a plating method. In this embodiment mode, the sputtering method is used, but the present invention is not limited to this. Further, in the present embodiment, the thickness of the metal layer is 10 μm or less in total with the thickness of the metal plating layer to be described later. This is because it is 10 μm or less. Naturally, even if the thickness is larger than this, the purpose of using it as a transfer foil can be achieved, for example, but since the purpose of this embodiment is to obtain an extremely thin metal foil, the thickness is 10 μm or less here. It is set. In addition, a thinner metal foil, specifically, a thickness of 5 μm or less has been desired recently, but it is described that the foil according to the present embodiment can sufficiently cope with the thickness. Keep it.

  A metal plating layer by metal plating is laminated on the surface of the metal layer. This metal plating layer is a layer obtained by simply performing metal plating on the surface of the metal layer by electrolytic plating or electroless plating. The metal plating layer in the present embodiment may be made of any one or more of copper, aluminum, nickel, chromium, or titanium, and in this embodiment, it is made of copper plating.

  The reason for providing the metal plating layer here is that the metal foil according to the present embodiment is as thin as possible and the surface is homogeneous, and it is particularly important that the surface is homogeneous. That's why. In other words, if only a metal layer laminated by sputtering is used as a metal foil, it is difficult to control the film thickness to a desired thickness. The main reason is that even though it is technically possible to form a uniform foil only by a metal layer formed by sputtering, the control is not easy.

  That is, in the metal foil with a support according to the present embodiment, peeling occurs between the peeling layer (surface copper oxide layer) and the metal layer (copper layer), and the metal layer (copper layer) and further Combined with the metal plating layer (copper plating layer) laminated on the surface, it is used as an extremely thin metal foil (copper foil). However, if only the metal layer (copper layer) is used, the foil (copper foil) is used. Since it is not easy to control the film thickness and the film uniformity, in this embodiment, a metal plating layer (copper plating layer) by metal plating that can easily control the film thickness and film uniformity is replaced with a metal layer (copper layer). In other words, it was used as an extremely thin metal foil (copper foil). In other words, in order to set the thickness of the ultra-thin metal foil (copper foil) to the desired thickness, the metal plating layer (copper plating layer) is used to control, so that the fine unevenness in the side view is filled with the metal plating. As a result, the film thickness is finally made uniform.

  From the opposite viewpoint, it is well known that it is preferable to previously provide a layer called an electrolytic seed layer in electrolytic plating in order to perform electrolytic plating reliably and beautifully. Then, the metal layer is laminated. In addition, the oxidized surface of the release layer on which the metal layer that acts as an electrolytic seed layer in electrolytic plating and the metal layer that is the electrolytic seed layer are exfoliated beautifully, thereby forming an electrode composed of the metal layer and the metal plating layer. A thin metal foil peels beautifully as an ultrathin metal foil.

  The purpose of the present embodiment is to obtain the above effect, and the most desirable mode for this purpose is that the release layer, the metal layer, and the metal plating layer are all made of the same metal. It can be said. In other words, even if the metal layer and the metal plating layer are different materials, it seems that there will be no problem, but when considering the actual use situation, for example, copper is used as the metal for forming the circuit pattern of the flexible circuit. In this case, the presence of a metal other than copper may cause trouble in terms of conductivity. In the end, when the two-layer structure is made of different metals, there is a possibility that delamination may occur even if it is very small. However, if these are made of the same metal, for example, copper, the surface of the copper Therefore, it is possible to reliably prevent peeling between them. Furthermore, when the release layer is made of the same material, for example, copper, for example, when the release layer, the metal layer, and the metal plating layer are laminated by the sputtering method, it can be carried out in exactly the same apparatus, that is, the manufacturing process. Therefore, it can be made very suitable in terms of production and production costs.

  Here, the description has been made on the assumption that electrolytic plating is performed. However, the electrolytic plating is not necessarily performed, and a metal plating layer may be formed by electroless plating. In addition, although the metal layer and the metal plating layer are copper as the metal to be used, it should be noted that there is no problem even if nickel, chromium, titanium or the like is used as the peeling layer in addition to copper.

  In addition, either electrolytic plating or electroless plating may be performed by a conventionally known plating method, and detailed description thereof is omitted here.

  As described above, the metal foil with a support according to the present embodiment has a configuration of PET film / copper layer (surface copper oxide layer) / copper layer / copper plating. Here, a brief summary will be given again.

  The entire manufacturing method includes a peeling layer laminating step in which a peeling layer is laminated on the surface of a polymer resin film that is a base material and a support, and a conductive metal is laminated on the surface of the peeling layer as a metal layer. And a plating process in which metal plating is performed on the surface of the metal layer to form a metal plating layer.

First, the peeling layer lamination step will be described.
Here, copper is first laminated on the surface of the PET film which is a base material, but in this embodiment, the thickness is laminated by a sputtering method so as to be 100 to 500 mm.

  Next, the surface of the laminated copper layer is oxidized to obtain a copper layer having an oxidized surface. The specific method in the present embodiment is performed by laminating the copper layer on the surface of the PET film and then releasing the entire copper layer to the atmosphere once. In this way, the surface of the first laminated copper layer is oxidized. In addition, the part oxidized at this time may be only the outermost surface of the copper layer in a schematic sectional view. This is because, as will be described later, when the metal foil with a support according to the present embodiment is used as a transfer foil, this oxidized portion acts as a release layer. In addition, when what is laminated | stacked is oxides beforehand, such as a silicon oxide, this oxidation process is unnecessary.

  When a laminate having the configuration of PET film / copper layer (surface oxidized) is obtained, that is, when the release layer laminating step is executed, the metal laminating step is performed next. In the present embodiment, copper is laminated on the surface of the copper layer whose surface is oxidized. The copper lamination method in this case is based on the sputtering method in this embodiment, and the thickness of the copper layer laminated here is preferably 10 μm or less.

  And if the laminated body of the structure of PET film / copper layer (surface oxidation finished) / copper layer (metal layer) was obtained by the metal lamination process, a plating process will be performed. In the present embodiment, copper plating is further performed on the surface. This copper plating is performed by a so-called generally well-known electrolytic plating method.

Finally, a metal foil with a support having a structure of PET film / copper layer (surface oxidized) / copper layer (metal layer) / copper plating is obtained. The copper layer (metal layer) and the copper plating portion are obtained. It is integrated into an extremely thin metal foil (copper foil).
Thus, the metal foil with a support according to the present embodiment is obtained.

  Next, an example of a method of using the obtained metal foil with a support will be described. Here, as described above, description will be made assuming that the structure is PET film / copper layer (surface copper oxide layer) / copper layer (metal layer) / copper plating.

  As explained at the beginning, for example, in recent years, flexible circuit boards are becoming increasingly thinner in response to lighter, thinner and smaller miniaturized electronic devices and mobile devices. That is, not only the base material constituting the flexible circuit board but also the copper foil forming the surface circuit is desired to be thinner.

  Therefore, the metal foil with a support according to the present embodiment, more specifically, an ultrathin copper foil using a PET film as a support can be used for the flexible circuit board.

Specifically, it is used as follows.
First, an adhesive is applied to the surface of an insulating base film that serves as a base of the flexible circuit board to form an adhesive layer. Next, the metal foil with a support according to the present embodiment is attached to the surface on which the adhesive layer is laminated. Specifically, a copper layer surface is stuck.

  And if this is affixed, the metal foil with a support body which affixed will be peeled. Thus, it will be in the state where copper foil was stuck on the base film surface. And only the circuit part is left among the copper foils stuck last, and the remainder is removed by etching. In this way, a circuit made of copper foil is formed on the surface of the base film.

  The following method is also conceivable. That is, after sticking the metal foil with a support on the surface of the base film, before peeling off the support, the unnecessary part together with the support is removed by etching, and then the support is peeled off. Thus, a circuit made of copper foil is formed.

  In this way, an ultrathin flexible circuit board can be obtained easily. If the base film is also made sufficiently thin, the whole can be made even thinner.

  That is, if the ultra-thin copper foil with a support according to the present embodiment is used, the thickness of the ultra-thin copper foil is 10 μm or less as described above. Therefore, it is possible to easily avoid the situation where the overall thickness cannot be reduced. In addition, in the metal foil with a support according to the present embodiment, the so-called release layer is an oxidized metal layer, and in particular, in this embodiment, the oxidized copper layer is used as the release layer. The copper layer portion corresponding to the ultrathin copper foil on the outermost surface peeled off reliably and beautifully, and the oxidized copper layer as the release layer did not adhere to the peeled surface.

  In addition, even if the release layer and the metal layer are different metals, the inventors of the present invention have found that the oxidized metal layer acts very effectively as the release layer of the transfer foil. This idea was used as a release layer in the metal foil with a support according to the present invention to be a transfer foil utilized. In order to form an oxidized metal layer, the surface of the release layer once laminated, here the copper layer, is oxidized by a method of opening to the atmosphere in this embodiment.

  As described above, when the metal foil with a support according to the present invention is used, it is possible to easily obtain an extremely thin metal foil and to obtain a metal foil having a substantially uniform film thickness. If this is used as a transfer material, an extremely thin metal foil can be easily transferred to a desired location. Furthermore, in the past, there was a problem that the residue of the release layer adhered to the ultrathin metal foil to be transferred, but in this embodiment, the occurrence of such a phenomenon can be avoided. In addition, the ultrathin metal foil obtained by transfer is not damaged, and a very suitable ultrathin metal foil transfer foil can be easily obtained.

  Next, although an example is given and the present invention is explained, the present invention is not limited to the following examples.

Basically, a metal foil with a support was obtained according to the production method according to the present invention.
That is, a release layer laminating step in which a release layer is laminated on the surface of the polymer resin film, a metal laminating step in which a conductive metal is laminated as a metal layer on the surface of the release layer, and a surface of the metal layer A metal foil with a support was obtained by sequentially performing a plating step in which metal plating was performed to form a metal plating layer.

  A PET film having a thickness of 50 μm (manufactured by Teijin DuPont Films Ltd .: product name “SLA”) was used as the polymer resin film.

  A metal or inorganic oxide is laminated as a release layer on the surface of this polymer film by sputtering using a well-known technique, and then the release layer lamination process is performed by oxidizing the surface of the laminated metal layer by releasing to the atmosphere. did. However, this oxidation process was not performed in Comparative Examples 1 and 2. When silicon oxide, aluminum oxide, and titanium oxide were laminated as a release layer, no special oxidation process was performed. The metal species, oxide species, and thicknesses selected as the release layer are as described in Table 1.

  Next, a copper layer, which is a metal layer, was laminated on the surface by a sputtering method so as to have a thickness of 200 nm or 100 nm as a metal lamination step.

  Next, copper was plated on the surface as a plating step so that the thickness was 3 μm to obtain a metal plating layer. The results regarding the peelability of the metal foil with a support thus obtained are shown in Table 1.

  As can be seen from this result, when the metal foil with a support according to the present invention is used, it can be seen that the peelability when the metal foil is peeled is good, but the comparative example is defective.

  Separately from this, it was made equivalent to the metal foil with a support according to the present invention (made copper foil), and the wiring processing aptitude when the thickness of the obtained copper foil was 3 μm, 8 μm and 16 μm was investigated. saw.

  Here, metal foils having respective thicknesses were used for well-known wiring processing that is usually performed, and it was examined whether or not they were exfoliated beautifully, in other words, whether or not wiring processing was completed beautifully. The obtained results are shown in Table 2. In the table, the pitch width refers to the interval between wirings.

  As can be seen from this result, in the case of a copper foil having a thickness of 3 μm, the wiring process is completed beautifully regardless of the pitch width, but in the case of a copper foil having a thickness of 8 μm, it is slightly cut when the pitch width is 50 μm. There was an example that was not enough. When the copper foil has a thickness of 16 μm, it can be seen that when the pitch width is 50 μm, the wiring process cannot be performed beautifully, that is, the thickness cannot be used for fine circuit formation.

  Therefore, when the total thickness of the metal layer and the metal plating layer is 10 μm or less and the metal layer and the metal plating are made of the same metal, the transfer is performed using the metal foil with a support according to the present invention. When the flexible circuit board is formed by the method, it can be seen that the flexible circuit board can be formed even if the pitch width of the flexible circuit is 50 μm or less.

Claims (3)

On the surface of the polymer resin film that is a substrate and is a support,
A release layer;
A metal layer made of a conductive metal;
A metal plating layer formed by metal plating and laminated in this order;
A metal foil with a support, characterized by:
The release layer is made of any one or more of copper, aluminum, nickel, chromium, silicon or titanium oxide,
The metal layer is one or more of copper, aluminum, nickel, chromium, or titanium,
The metal plating layer is made of one or more of copper, aluminum, nickel, chromium, or titanium,
The total thickness of the metal layer and the metal plating layer is 10 μm or less, and the metal layer and the metal plating are made of the same metal,
When forming a flexible circuit board by a transfer method using the metal foil with the support, it is possible to form a flexible circuit board even if the pitch width of the flexible circuit is 50 μm or less,
A metal foil with a support. A release layer laminating step in which a release layer is laminated on the surface of the polymer resin film which is a base material and is a support;
A metal lamination step in which a conductive metal is laminated on the surface of the release layer as a metal layer;
A plating step in which a metal plating is applied to the surface of the metal layer to form a metal plating layer;
And
When oxidizing the surface of the metal layer after the metal lamination step, performing an oxidation step of oxidizing the surface of the metal layer before the plating step;
A method for producing a metal foil with a support, characterized in that
The release layer is made of any one or more of copper, aluminum, nickel, chromium, silicon or titanium oxide,
The metal is any one or more of copper, aluminum, nickel, chromium, or titanium,
The metal plating is made of one or more of copper, aluminum, nickel, chromium, or titanium,
The total thickness of the metal layer and the metal plating layer is 10 μm or less, and the metal layer and the metal plating are made of the same metal,
When forming a flexible circuit board by a transfer method using the metal foil with the support, it is possible to form a flexible circuit board even if the pitch width of the flexible circuit is 50 μm or less,
The manufacturing method of the metal foil with a support body characterized by these. The metal foil with a support according to claim 1 or the metal foil with a support obtained by the production method according to claim 2 is used as a metal foil for wiring processing in a flexible circuit board,
A flexible circuit board.