JP5517019B2 - Printed wiring board and method for manufacturing printed wiring board - Google Patents

Description

  The present invention relates to a printed wiring board and a method for manufacturing the same, and more specifically, a metal layer having good etching property and a metal layer having high corrosion resistance are sequentially formed between an insulating resin film and a copper coating layer by a dry plating method. The present invention relates to a printed wiring board having high insulation reliability and a method for manufacturing the same.

A flexible printed wiring board includes a three-layer resin film metal film laminated substrate (for example, see Patent Document 1) in which a copper foil serving as a conductor layer is bonded onto an insulating resin film using an adhesive, and an insulating resin film. It is roughly classified into a two-layer resin film metal film laminated substrate in which a copper coating layer as a conductor layer is directly formed by a dry plating method or a wet plating method without using an adhesive.

By the way, with the recent increase in the density of electronic devices, a wiring board having a narrower wiring width has been required. In the production of the above three-layer resin film metal film laminated substrate , copper formed on an insulating resin film is required. A conductor wiring portion is formed by etching the coating layer in accordance with a desired wiring pattern, but so-called side etching occurs in which the side surface of the conductor wiring portion is excessively etched, resulting in a cross-sectional shape of the wiring portion. There is a problem that it tends to be a trapezoid with a wide hem.

For this reason, in order to solve this problem, a two-layer resin film metal film laminated substrate is now becoming mainstream in place of the conventional bonded copper foil (three-layer resin film metal film multilayer substrate ).
In this two-layer resin film metal film laminated substrate , a copper coating layer having a uniform thickness is formed on an insulating resin film, and an electroplating method is usually employed as the means. In order to perform electroplating, it is common to form a thin metal layer on the insulating resin film before electroplating to impart conductivity to the entire surface, and to perform electroplating thereon ( For example, see Patent Document 2). The thin metal layer formed on the insulating resin film is formed using a dry plating method such as a vacuum deposition method or an ion plating method.

In such circumstances, the adhesion between the insulating resin film and the copper coating layer becomes very weak when a brittle layer such as CuO or Cu ₂ O is formed at the interface. In order to maintain the adhesive strength with the layer, a nickel-chromium alloy layer is provided as a base metal layer between the insulating resin film and the copper coating layer (see Patent Document 3). Hereinafter, a laminate composed of a base metal layer and a copper coating layer is referred to as a metal film.

The wiring pattern of the two-layer resin film metal film laminated substrate is formed by a subtractive method. The subtractive method is a manufacturing method for manufacturing a printed wiring board by removing unnecessary portions of the metal film of the resin film metal film laminated substrate by chemical etching.
This chemical etching process consists of erosion of the metal film that is no longer required by the chemical etching solution and washing with water for removing the chemical etching solution. In the chemical etching process, the chemical etching solution or water is sprayed in a shower, It is common to immerse in a chemical etching solution or the like.

The chemical etching solution which corresponds to the etching of the copper coating layer, for example, ferric and _(FeCl 3 · _2H 2 O) aqueous solution of chloride, cupric chloride acidified with hydrochloric acid _(CuCl 2 · _2H 2 O) has an aqueous solution, A chemical etching process using these is performed to form a conductor wiring.
In the chemical etching method using these chemical etching solutions, if a nickel-chromium alloy with a high chromium content is used as the underlying metal layer from the viewpoint of corrosion resistance, chemical etching is not sufficient, and the edge of the conductor wiring or the conductor wiring In some cases, the underlying metal layer remains undissolved, and a metal residue that is an etching residue is generated, so that a sufficient etching result cannot be obtained.

  Furthermore, as a problem in terms of insulation reliability, a constant temperature and humidity bias test (hereinafter, referred to as HHBT test; High Temperature High Bias Test) is performed as an index of insulation reliability. It has been clarified that the insulation reliability in the HHBT test is not sufficient for a substrate on which the above-described etching residue is formed or a flexible printed wiring board using a base metal layer having a low chromium content.

That is, when the above-mentioned chemical etching treatment is performed on a two-layer resin film metal film laminated substrate having a base metal layer with a high chromium content, the base metal layer such as a nickel-chromium alloy remains undissolved due to insufficient etching. When the HHBT test is performed, there is a problem that adjacent conductor wirings are short-circuited by a metal residue composed of a base metal layer component remaining undissolved between the wirings.
On the other hand, in the two-layer resin film metal film laminated substrate having the base metal layer with a low chromium content, no etching residue is generated, but the corrosion resistance of the base metal layer cannot be ensured, so that the insulation reliability in the HHBT test cannot be ensured. Therefore, the base metal layer is required to have the opposite characteristics of etching property and corrosion resistance.

Therefore, as one of means for realizing the insulation reliability, it is necessary to remove the etching residue remaining between the conductor wirings described above. after ferric chloride solution or hydrochloric acid cupric chloride solution is a chemical etching solution which corresponds to the copper film etching treatment, acid etching solution containing hydrochloric acid, one of the alkaline etching solution such as potassium permanganate solution or 2 It has been proposed to dissolve etching residues between wirings by using a combination of seeds or more.

  Furthermore, Patent Document 5 proposes that the etching residue between wirings is chemically etched with a solution containing hydrochloric acid and sulfuric acid, and further immersed in a mixed solution of potassium permanganate, potassium hydroxide, and sodium hydroxide. ing.

Further, Patent Document 6 proposes that an etching residue between wirings is dissolved with an acidic chemical etching solution containing hydrochloric acid and further treated with an alkaline etching solution containing potassium ferricyanide or permanganate. When an alkaline etching solution containing potassium ferricyanide or permanganate is used, it is possible to remove the nickel chromium alloy or nickel chromium molybdenum alloy remaining undissolved between the wirings by a method with little side etching of the copper wiring.
JP-A-6-132628 Japanese Patent Laid-Open No. 8-139448 JP-A-6-120630 JP 2005-23340 A Japanese Patent No. 3888587 JP 2008-28150 A

However, recent flexible printed circuit boards have become increasingly narrower in pitch due to higher density of wiring patterns, and have been required to be used at higher voltages with higher functionality. As a result, the insulation reliability of the printed wiring board to be used is important, and the base metal layer is required to have higher corrosion resistance in order to withstand high voltages.
Therefore, there is a tendency to provide a base layer with a high chromium content of the nickel-chromium alloy from the viewpoint of corrosion resistance, but as a result, an etching residue is generated in which the components of the base metal layer are not dissolved between the conductor wires by the chemical etching process. There is a tendency to increase.

Further, conventionally, when forming a conductive wiring pattern using a two-layer resin film metal layer laminated substrate subtractive method, an etching treatment with one type of chemical etching solution of ferric chloride aqueous solution or hydrochloric acid cupric chloride aqueous solution Therefore, the increase in the number of etching processes for removing etching residues has the problem of increasing the equipment cost and liquid management cost due to the need to introduce new equipment, and reducing the production efficiency due to the increased process. There is a risk of being invited.

The present invention has been made to solve such various problems, and the object thereof is at least one surface of an insulating resin film in the production of a flexible printed wiring board using a dry plating method and an electroplating method. the underlying metal layer is formed on, in forming a copper coating layer on the base metal layer, a high etching resistance during formation of the conductor wiring, specifically in an aqueous solution of ferric or hydrochloric acid cupric chloride aqueous chloride Provided is a printed wiring board having a high insulation reliability and corrosion resistance when a high voltage is applied between conductor wirings, and a method for manufacturing the same, with less etching residue of a base metal layer component remaining between conductor wirings when etched. There is.

In view of such a situation, as a result of intensive studies by the inventor, the metal layer B, the metal layer C, and the copper coating layer D are laminated on one side or both sides of the insulating resin film without using an adhesive. Thus, it has been found that a printed circuit board having both insulation reliability and corrosion resistance can be realized.
According to the first aspect of the present invention, an unnecessary portion of the metal film of the resin film metal film laminated substrate in which the metal film is laminated on at least one surface of the insulating resin film A without using an adhesive is selectively processed by chemical etching. A printed wiring board on which a conductor wiring is formed by removing a nickel film or a nickel film on which the metal film constituting the conductor wiring is laminated on the surface of the insulating resin film A, and containing 70 mass% or more of chromium. nickel containing less than 15 mass% - a metal layer B made of chromium alloy, said laminated on the surface of the metal layer B, comprising nickel, Ri Do an alloy containing chromium least 15 mass%, thickness 5Nm～37nm, or and the metal layer C and the total of the metal layer B is 40nm or less than 5 nm, laminated on the surface of the metal layer C, the copper film thickness 10nm~35μm Consists of a layer D, the copper coating layer D by using only chemical etchant for etching, a printed wiring board, characterized in that the selective removal of unwanted portions of the metal film.

According to a second aspect of the present invention, a conductor wiring composed of the metal film in which the metal layer B, the metal layer C, and the copper coating layer D are sequentially laminated is chemically treated with a ferric chloride aqueous solution or a hydrochloric acid acidic cupric chloride aqueous solution. The amount of residual metal remaining on the insulating resin film A after the etching treatment is 0.13 μg / cm ² or less per unit area of the insulating resin film A. It is a printed wiring board.

  According to a third aspect of the present invention, the metal layer B includes nickel-chrome containing 13 mass% or less of vanadium, 8 mass% or less of titanium, 20 mass% or less of molybdenum, 70 mass% or more of the remaining nickel or nickel, and less than 15 mass% of chromium. The printed wiring board according to the first invention or the second invention, characterized in that it is made of an alloy and 1% by mass or less of inevitable impurities and has a film thickness of 3 to 20 nm.

According to a fourth aspect of the present invention, the metal layer C contains 15 mass% or more of chromium, 0.01 to 85 mass% of nickel, and an alloy composed of unavoidable impurities of 1 mass% or less, or 15 mass% or more of chromium and 0.1% of nickel. The printed wiring board according to any one of the first to third inventions, wherein the printed wiring board is an alloy composed of inevitable impurities of 01 to 85 mass% and molybdenum of 0.01 to 40 mass% and 1 mass% or less. is there.

  A fifth invention is the printed wiring board according to any one of the first to third inventions, wherein the chemical etching solution does not contain manganese and a cyanide compound.

A sixth invention is the chemical etchant, the printed wiring board as set forth in the first invention to any of the third invention, characterized in that the aqueous solution of ferric or hydrochloric acid cupric chloride aqueous chloride It is.

In the seventh invention, the insulating resin film A is selected from a polyimide film, a polyamide film, a polyester film, a polytetrafluoroethylene film, a polyphenylene sulfide film, a polyethylene naphthalate film, and a liquid crystal polymer film. The printed wiring board according to the first invention or the second invention, wherein the printed wiring board is at least one kind of resin film.

In an eighth aspect of the invention, an unnecessary portion of the metal film is selected by chemical etching of the metal film of the resin film metal film laminated substrate in which the metal film is laminated on at least one surface of the insulating resin film A without using an adhesive. a removed to printed circuit board manufacturing method of forming the conductor wiring, the resin film metal layer laminated substrate, the nickel on the surface of the insulating resin film a, or nickel 70 mass% or more, chromium 15 mass% nickel containing less than - a metallic layer B made of chromium alloy was formed by dry plating method, and then, an alloy consisting of 15 mass% or more of chromium and nickel to the surface of the metal layer B, or 15 mass% or more chromium, nickel and molybdenum composed of an alloy consisting of the sum of film thickness 5Nm～37nm, or 5nm or more and the metal layer B is 4 After the metal layer C is nm or less is formed by a dry plating method, the surface of the metal layer C, to form a metal film formed by laminating a copper coating layer D having a thickness 10Nm～35myuemu, one type of the metal film A method of manufacturing a printed wiring board, wherein conductive wiring is formed by selective removal with an etchant.

  A ninth invention is the method for producing a printed wiring board according to the eighth invention, wherein the chemical etching solution does not contain manganese and a cyanide compound.

A tenth aspect of the invention, the chemical etchant is an eighth method for manufacturing a printed wiring board according to the invention, which is a ferric solution or hydrochloric acid cupric chloride aqueous chloride.

  The eleventh invention is the production of a printed wiring board according to the eighth invention, wherein the copper coating layer D forms a copper layer by electroplating on the surface of the copper layer formed by dry plating. Is the method.

  According to a twelfth aspect of the printed wiring board of the eighth or eleventh aspect, the dry plating method is any one of a vacuum deposition method, a sputtering method, and an ion plating method. It is a manufacturing method.

  The printed wiring board of the present invention has excellent corrosion resistance because the metal layer C containing 15 mass% or more of chromium is disposed between the insulating resin film A and the copper coating layer D, and has excellent corrosion resistance, and the insulating resin film A and the metal layer C. The metal layer B made of an alloy having a chromium content of less than 15 mass% is disposed between the metal film without any residue with one kind of chemical etching solution, and the insulation reliability of the printed wiring board. The industrial use value is extremely high.

The printed wiring board of the present invention is manufactured by subjecting a two-layer resin film metal film laminated substrate (hereinafter referred to as a resin film metal film laminated substrate ) to processing by a subtractive method or a semi-additive method.

(1) Resin film metal film laminate substrate The resin film metal film laminate used for the printed wiring board of the present invention has a metal layer B and a metal layer C on at least one surface of the insulating resin film A without an adhesive. The metal film laminated | stacked in order of the copper coating layer D is formed.
The cross section of the resin film metal film laminated body used for the printed wiring board of this invention in FIG. 1 is shown. The metal layer B and the metal layer C correspond to the base metal layer of the two-layer resin film metal film laminated substrate . Moreover, this resin film metal film laminated body corresponds to a two-layer resin film metal film laminated substrate because the insulating resin film A and each metal layer are laminated and there is no adhesive layer.

Each component of the resin film metal film laminated substrate of the present invention will be described in detail.
(Metal layer B)
The metal layer B is laminated on the surface of the insulating resin film A without using an adhesive, and is made of nickel or an alloy containing 70 mass% or more of nickel and less than 15 mass% of chromium. The chromium content of the metal layer B is desirably 14.5 mass% or less, and more desirably 14 mass% or less. If the content of chromium is more than 15 mass%, it is impossible to maintain the insulation reliability can not be removed metal layer B by chemical etching with an aqueous ferric or hydrochloric acid cupric chloride aqueous chloride.

The metal layer B can contain vanadium at 13 mass% or less, titanium at 8 mass% or less, and molybdenum at 20 mass% or less.
As for the inclusion of vanadium, titanium, and molybdenum, one selected element may be added to the metal layer B, or a plurality of elements may be added. That is, the metal layer B may be an alloy composed of one element selected from nickel and vanadium, titanium, and molybdenum, or an alloy composed of two or more elements selected from nickel, vanadium, titanium, and molybdenum. good. Furthermore, it may be an alloy composed of nickel and chromium, and one element selected from vanadium, titanium, and molybdenum, and nickel, chromium, and two or more elements selected from vanadium, titanium, and molybdenum. An alloy made of may be used.

Vanadium, titanium, each element of the molybdenum improves the corrosion resistance of the metal layer B, below 13 mass% in vanadium, less 8mass% is titanium, if the molybdenum is in a content of less 20 mass%, an aqueous solution of ferric or hydrochloric chloride in the etching step with an acidic cupric chloride aqueous solution, it does not generate residue of the metal layer B. In the case where the additional element of the metal layer B is composed of only titanium residue of the metal layer B occurs in the etching step with an aqueous ferric or hydrochloric acid cupric chloride aqueous chloride.
As described above, a transition metal element can be appropriately added to the metal layer B in accordance with target characteristics for the purpose of improving heat resistance and corrosion resistance. In addition to these alloys, the metal layer B may contain 1% by mass or less of unavoidable impurities contained by being taken in at the time of target production.

  As a method for forming the metal layer B, a known vapor deposition method, sputtering method, or ion plating method can be used. In particular, the sputtering method is preferable because an alloy having a desired component composition can be formed without causing a composition variation.

Thickness of the metal layer B is, if thinner than 3nm, the conductor interconnect metal layer C Keep chemical etching with an aqueous ferric or hydrochloric acid cupric chloride aqueous chloride at conductor wiring processing not dissolved with the metal layer B It will melt away. This is because the metal layer B is not formed as a complete film, so the metal layer C is locally formed directly on the insulating resin film A, or the metal layer C is dissolved together with the metal layer B. This is probably because the metal layer B should be as thin as possible in view of the corrosion resistance after processing the conductor wiring. When the film thickness is larger than 20 nm, the component of the metal layer B gradually elutes when a voltage is applied to the conductor wiring, which tends to cause a short circuit failure.
The film thickness of the metal layer B is estimated from the formation conditions. For example, when the sputtering method is used, the film thickness is linear depending on the formation conditions such as the input power to the sputtering cathode and the sputtering time. It is known that the thickness of the metal layer B can be determined from the conditions.

(Metal layer C)
The metal layer C is formed on the surface of the metal layer B on the insulating resin film A without using an adhesive.
The metal layer C is an alloy mainly composed of nickel and chromium. However, if the chromium content is less than 15 mass%, the corrosion resistance after the wiring processing cannot be maintained sufficiently, and the metal layer C or copper is eluted and the insulation reliability is increased. Sex is reduced. On the other hand, if the chromium content exceeds 70%, chromium may be precipitated at the grain boundary, which is not preferable. Further, if the metal layer C is composed only of Cr, the acid resistance is lowered because it dissolves with hydrochloric acid. Therefore, if the etching process and the plating process are performed, the insulation reliability is lowered, so 15 to 70 mass% is desirable.

Furthermore, the nickel content of the metal layer C is preferably 0.01 to 85 mass % after securing the chromium content.
Further, the metal layer C may also contain molybdenum 0.01～40Mass% until. In that case, it is needless to say that the content is adjusted to 100 mass% together with the contents of nickel, chromium and inevitable impurities.
Molybdenum also has an effect of improving corrosion resistance. If the molybdenum content exceeds 40 mass%, the heat-resistant peel strength tends to be extremely lowered, which is not preferable.

If the thickness of the metal layer C is less than 5 nm, the barrier property against copper cannot be ensured and the insulation reliability is lowered. Moreover, when the total film thickness of the metal layer B and the metal layer C exceeds 40 nm, the stress of the film increases, hair cracks and warpage may occur, and the adhesion strength may decrease, and the metal layer B and the metal layer C The total film thickness is desirably 40 nm or less.
The film thickness of the metal layer C is obtained from the formation conditions. For example, when the sputtering method is used, the film thickness may change linearly depending on conditions such as input power to the sputtering cathode and sputtering time. The film thickness is determined from the known conditions.

(Copper coating layer D)
Next, the copper coating layer D is formed using a dry plating method when the copper coating layer is formed relatively thin. On the other hand, after a thin copper coating layer is formed by a dry plating method, a thicker copper coating layer may be laminated on the thin copper coating layer by using a wet plating method.
The thickness of the copper coating layer is desirably 10 nm to 35 μm. If the film thickness is less than 10 nm, a problem may occur in the electrical conductivity of the wiring part, or a problem in strength may appear. There is sex. On the other hand, when the film thickness exceeds 35 μm, it is not preferable because a hair crack or warp may occur and the adhesion strength may be lowered.

  When a copper coating layer is formed by a dry plating method and then a thicker copper coating layer is formed on the copper coating layer by a wet plating method, the film thickness is about 10 nm to 1 μm by the dry plating method. After the copper coating layer is formed, the copper coating layer or the conductor wiring having a desired film thickness may be laminated by a wet plating method.

(Insulating resin film)
The insulating resin film is a polyimide film, a polyamide film, a polyester film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polytetrafluoroethylene film, a polyphenylene sulfide film, a polyethylene naphthalate film, or An insulating resin film selected from liquid crystal polymer films can be appropriately selected according to the application in consideration of heat resistance, dielectric properties, electrical insulation, chemical resistance in the manufacturing process of the printed wiring board and the next process, and the like.

For example, for polyimide films, Kapton (registered trademark) manufactured by Toray DuPont Co., Ltd., Upilex (registered trademark) manufactured by Ube Industries, Ltd., Apical (registered trademark) manufactured by Kaneka Chemical Co., Ltd., Toyobo There is XENO (registered trademark) manufactured by Co., Ltd. In addition, examples of the aramid film that is an aromatic polyamide film include Mikutron (registered trademark) manufactured by Toray Industries, Inc. and Aramika (registered trademark) manufactured by Teijin Advanced Films.
The printed wiring board of the present invention can be used for a printed wiring board in which conductor wiring is formed on both sides of the insulating resin film A, as well as a printed wiring board in which conductor wiring is formed on one side of the insulating resin film A. it can. Furthermore, a plurality of printed wiring boards of the present invention can be laminated to be used as a multilayer printed wiring board.

(Amount of metal residue)
Next, the amount of metal residue remaining on the insulating resin film A will be described.
If a layer made of metal atoms remains between the wirings, the HHBT test leads to a short circuit between the wirings over time and causes a significant decrease in insulation reliability. Although there are portions that remain locally biased, it is known that the amount of metal residue when the entire surface of the insulating resin film is covered with one metal atom layer corresponds to about 0.15 μg / cm ² .

Therefore, nickel - in order to know the relationship chromium content of the chromium alloy and the residual amount of the insulating resin film, the nickel by sputtering advance moisture on drying the removed insulating resin film (polyimide film) - chromium alloy (metal to form the corresponding) to the layer B or the metal layer C, followed the substrate formed with the copper coating layer is etched in ferric chloride solution by sputtering and electroplating, nickel at that time - chromium concentration of chromium in the alloy and the polyimide film The relationship with the sum of the components of the nickel-chromium alloy layer remaining on the top, that is, the sum of the etching residue amounts was determined. The result is shown in FIG.

In FIG. 2, when the chromium content is 15 mass%, in the case where the etching residue amount on the insulating resin film is large, it is 0.15 μg / cm ² per 1 cm ^{2 of the} insulating resin film, and this value is as described above. This is equivalent to the amount of the entire surface of the insulating resin film covered with a single layer of metal atoms. Actually, there are parts that remain locally biased, but there are layers of metal atoms between the wires. If it remains, in the HHBT test, the wiring will be short-circuited over time and the insulation reliability will be greatly reduced.

In particular, in order to form a high-definition wiring with a pitch of several tens of μm, it is required to remove an unnecessary portion of the metal film by etching, but the chromium content with high corrosion resistance is 15 mass% or more on the surface of the insulating resin film. When the metal film laminated substrate with the resin film is chemically etched with ferric chloride aqueous solution and processed into a printed wiring board, the unnecessary metal film is removed and the surface of the insulating resin film A is visually observed. However, since one or more metal atomic layers remain between the wirings, sufficient insulation reliability cannot be obtained.

  In contrast, when a metal layer having a chromium content of less than 15 mass% is provided on the surface of the insulating resin film and a metal layer having a high chromium content is provided on the metal layer, a chemical etching solution for etching copper is used. Even if only a certain ferric chloride aqueous solution or hydrochloric acid acidic cupric chloride aqueous solution is used, an unnecessary portion of the metal layer having a high chromium content can be removed by chemical etching. On the contrary, when a metal layer having a chromium content of 15 mass% or more is provided on the insulating resin film and a metal layer having a low chromium content is provided on the metal layer, an aqueous ferric chloride solution or acidic hydrochloric acid chloride is used. It is difficult to remove a metal layer with an unnecessary portion of chromium content of 15 mass% or more with only an aqueous copper solution, and it is difficult to remove without using a chemical etching solution containing manganese or cyanide such as potassium permanganate and potassium ferricyanide. It becomes.

Therefore, in the printed wiring board of the present invention, the amount of metal residue remaining in the insulating resin film A after etching the conductor wiring composed of the metal layer B, the metal layer C, and the copper coating layer D with a ferric chloride aqueous solution is Further, it is 0.13 μg / cm ² or less per unit area of the insulating resin film A, and more desirably 0.10 μg / cm ² or less.
Further, when the conductor wiring on which the metal layer B, the metal layer C, and the copper coating layer D are laminated is removed, the surface of the insulating resin film A is exposed and metal residues due to etching also appear on the surface of the insulating resin film A. By measuring the amount of metal remaining on the insulating resin film A where the surface is exposed, the amount of metal residue after etching is obtained, and therefore the insulation reliability is estimated.

The amount of metal residue remaining on the insulating resin film A is measured by the following procedure.
Conductor wiring of the printed wiring board is chemically etched with ferric chloride aqueous solution or acidic acidic cupric chloride aqueous solution to remove unnecessary parts, exposing the surface of insulating resin film A, and cleaning or post-processing as necessary I do. Next, the metal component remaining in the surface layer portion of the printed wiring board from which the conductor wiring has been removed, that is, the exposed surface layer portion of the insulating resin film A, is dissolved to obtain a solution of the remaining metal component.

  An acid is used to dissolve the residual metal component, but those containing components that interfere with the detection spectrum in the quantitative analysis of the metal component cannot be used. For example, hydrochloric acid is effective for easily dissolving residual metals such as Ni, Cu, Mo, Ta, Ti, V, Cr, Fe, and Co. Hydrochloric acid has a Cl detection spectrum of the above metal component. This is not preferable because it may interfere with a large detection spectrum. Nitric acid does not interfere with the above detection spectrum, but after dissolution with nitric acid, undissolved metal components are likely to be generated on the insulating film side, which is inappropriate as a solution.

  Therefore, in the present invention, for dissolving the metal component remaining on the surface layer portion of the insulating resin film after etching, a microwave decomposition apparatus is used by using a solution composed of 70 to 90% nitric acid and 10 to 30% hydrogen peroxide. Dissolve with By this method, the detection spectrum is not disturbed during quantitative analysis, and all the metal components remaining on the insulating film can be completely dissolved.

  Also, by using this microwave decomposition apparatus, unlike the case of indirect heating with a hot plate or the like, the acid inside the sealed container is directly heated with microwaves, so there is little heat escaping to the outside, and contamination from the outside is also prevented. Less. Accordingly, since the residual metal component can be decomposed with a small amount of acid in a short time, the sample can be decomposed and measured for about 5 to 6 hours, which enables an extremely quick evaluation.

  The metal component of the solution thus obtained is quantitatively analyzed. The analysis method is not particularly limited, but it is preferable to use an inductively coupled plasma ion source mass spectrometer (hereinafter sometimes referred to as ICP-MS) capable of quantifying a trace amount of metal components. .

(Chemical etchant)
The chemical etching solution used in the present invention is a chemical etching solution for etching a copper coating layer, and is preferably a chemical etching solution of either a ferric chloride aqueous solution or a hydrochloric acid acidic cupric chloride aqueous solution. The ferric chloride aqueous solution or the hydrochloric acid acidic cupric chloride aqueous solution oxidizes and etches copper, and removes the metal layer B and the metal layer C in the laminated structure of the metal film of the present invention.

  In general, from the viewpoint of corrosion resistance, a copper film layer is etched from a resin film metal film laminate in which a base metal layer (metal layer C in the present invention) of a nickel-chromium alloy having a high chromium content is provided on the surface of an insulating resin film. When a printed wiring board is produced by chemical etching treatment with an aqueous ferric chloride solution or an acidic cupric chloride aqueous solution, unnecessary portions of the underlying metal layer remain without being completely removed by etching. May result in metal residue.

  In particular, when the chromium content of the base metal layer is 15 mass% or more, the generation of metal residues due to etching is noticeable, and the base metal layer component remains with a thickness of 0.1 to several nm from the surface of the insulating resin film. In some cases, the removal requires a dissolution treatment with a potassium ferricyanide aqueous solution or an alkaline permanganate aqueous solution that dissolves the metal residue. Further, the base metal layer may be passivated with an aqueous ferric chloride solution, and such passivation of the base metal layer becomes a metal residue in etching, which causes a decrease in insulation reliability.

  On the other hand, the printed wiring board of the present invention has a laminated structure in which the metal layer B, the metal layer C, and the copper coating layer D are provided in this order on the surface of the insulating resin film A, and the metal layer C containing 15 mass% or more of chromium is insulated. Even when provided between the resin film A and the copper coating layer D, the metal layer C and the insulating resin film A contain less than 15 mass% of chromium etched with a chemical etching solution for etching the copper coating layer D. Since the metal layer B is interposed, the metal layer C is included even if the chemical etching process (for example, ferric chloride aqueous solution or hydrochloric acid acidic cupric chloride aqueous solution) corresponding to the copper coating layer D is used alone. Unnecessary portions of the metal film can be removed.

  The metal film provided on the surface of the insulating resin film A is a laminated structure in which the metal layer B, the metal layer C, and the copper coating layer D are provided in this order, so that chemical etching treatment is performed with an aqueous potassium ferricyanide solution or an alkaline permanganate aqueous solution. Although the reason why the metal layer B, the metal layer C, and the copper coating layer D can be removed is not clear, the order of lamination on the surface of the insulating resin film A is determined by the metal layer C, the metal layer B, and the copper coating layer D In such a case, when a chemical etching process is performed with a ferric chloride aqueous solution or a hydrochloric acid acidic cupric chloride aqueous solution, a metal residue of the metal layer C component is generated.

(2) Method for Manufacturing Printed Wiring Board Next, a method for manufacturing a printed wiring board according to the present invention will be described in detail.
A printed wiring board is manufactured by processing a resin film metal film laminated substrate using a subtractive method or a semi-additive method. That is, the metal film composed of the copper film layer D, the metal layer C, and the metal layer B on the surface of the resin film metal film laminated substrate is removed by chemical etching or the like to become a conductor wiring.

Below, the case where the printed wiring board of this invention is manufactured by a subtractive method is demonstrated. The subtractive method is a manufacturing method for manufacturing a printed wiring board by removing unnecessary portions of the metal film of the resin film metal film laminated substrate by chemical etching.

In the printed wiring board of the present invention, a resist is disposed on the surface of a portion of the metal film of the resin film metal film laminated substrate that is desired to be left as a conductor wiring. That is, the resist has a wiring pattern shape. Thereafter, a chemical etching process using a chemical etching solution corresponding to the copper coating layer and water washing are performed, and unnecessary portions of the metal film are selectively removed to form conductor wiring.
This selective removal is possible because the chemical etching process to the metal film can be performed with only one type of chemical etching liquid that etches the copper coating layer, so that the number of etching process steps is not newly increased. There is no need to introduce new equipment, and there is no increase in equipment costs, liquid management costs or man-hours.

  A known resist may be used as long as it is resistant to a chemical etching solution and can be removed after the wiring is formed. The resist is arranged on the surface of the copper coating layer D by screen printing, or by being cured into a predetermined shape if it is a photosensitive resist that is cured by irradiation with ultraviolet rays or the like.

  In the present invention, unnecessary portions are removed by etching the metal film with only one chemical etching solution of either ferric chloride aqueous solution or acidic hydrochloric acid cupric chloride aqueous solution for etching the copper coating layer. The ferric chloride aqueous solution or the acidic hydrochloric acid cupric chloride aqueous solution has a function of oxidizing and etching copper and removing the metal layer B and the metal layer C in the laminated structure of the metal film of the present invention. .

In this way, the chemical etching solution does not use an aqueous solution of permanganate such as an aqueous potassium permanganate solution or a cyanide compound such as potassium ferricyanide, so that it is not necessary to remove manganese after the etching process. Therefore, the printed wiring board before the gold plating process does not contain manganese or cyanide, and even the printed wiring board that has been subjected to gold plating does not contain manganese.
In addition, manganese and a cyanide compound as an unavoidable impurity are excluded that manganese and a cyanide compound are not contained.

  Moreover, the printed wiring board of the present invention does not perform a chemical etching process with a chemical etching solution corresponding to the etching of the metal layer C. Among the chemical etching solutions corresponding to the metal layer C, the alkaline permanganate aqueous solution removes the surface layer of the insulating resin film A. However, since the alkaline permanganate aqueous solution is not used, the metal layer C is removed. However, the surface of the insulating resin film is not removed. That is, when the conductor wiring composed of the metal layer B, the metal layer C, and the copper coating layer D is removed with a ferric chloride aqueous solution, and the unevenness of the exposed surface of the insulating resin film A is measured with an optical profiler, it is below the measurement limit. It turns out that it is smooth. This means that the exposed surface of the insulating resin film A is not dissolved by the chemical etching solution.

  The removal of the oxide film formed on the surface of the conductor wiring after the formation of the conductor wiring may be performed by using known micro-etching or chemical etching corresponding to the copper coating after forming the conductor wiring of the printed wiring board. The use of a chemical etching solution other than the solution may be appropriately selected depending on the subsequent steps.

Next, the case where the printed wiring board of the present invention is manufactured by a semi-additive method will be described.
The semi-additive process, the surface of the tree lipid film metal layer laminated substrate of the metal film, and deposited was the metal film at a location desired to form a wire, after securing the film thickness of the wiring, unnecessary surface of the insulating resin film This is a method for producing a printed wiring board by removing the metal film.

With details, a resist film is formed at a position on the surface of the tree lipid film metal layer laminated substrate of the metal film is not desired in the formation of wiring, copper wiring was formed by electroplating or the like on the exposed surface of the metal film, formed of the copper wiring Thereafter, the metal film exposed by removing the resist is removed by a chemical etching process to form a wiring, and a printed wiring board is manufactured.
The resist used here may be any known resist as long as it can withstand a copper plating solution. Further, the unnecessary metal film is removed by the same method as the subtractive method in which the surface is a copper coating layer and is removed with a chemical etching solution corresponding to copper.

  Although the present invention has been described so far with respect to a flexible printed wiring board using a flexible insulating resin film, a rigid printed wiring board using a material such as an epoxy resin, a phenol resin, or Teflon (registered trademark) can also be used. Of course, the present invention can be implemented.

The present invention will be described below with reference to examples.
Using a polyimide film (product name “Kapton 150EN” manufactured by Toray Deyupon Co., Ltd.) with a film thickness of 38 μm for the insulating resin film A, a metal layer B, a metal layer C, and a copper coating layer D are laminated in order to form a resin film metal film laminate A substrate was produced. About the obtained resin film metal film | membrane laminated substrate , initial stage peel strength, heat-resistant peel strength, etching property, the amount of metal residues after an etching, and insulation reliability were evaluated. Samples described in the following (a), (b), and (c) are used unless otherwise specified.

(A) Measurement of peel strength The initial peel strength was measured by a measurement method based on IPC-TM-650 and NUMBER 2.4.9. The measurement condition is that the peel angle is 90 °. The sample has a lead width of 1 mm, and a photosensitive resist (PMER P-RH30 PM manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to the surface of the copper coating layer D of the resin film metal film laminated substrate to form a pattern with a width of 1 mm. exposed and developed in a concentration not more than 0.3 mass% aqueous sodium carbonate solution, ferric chloride solution was immersed for 2 minutes (the specific gravity 40 ° Baume, the temperature 43 ° C.), washed with water, formed by the subtractive method to be dried. For removing the resist, an aqueous sodium hydroxide solution having a concentration of 4 mass% was used.
The heat-resistant peel strength is the same as the initial peel strength. After holding the sample at 150 ° C. for 168 hours, taking it out and cooling it to room temperature, the peel angle is set to 90 ° as with the initial peel strength. The strength was determined to be good if the initial peel strength was 600 N / m or higher and the peel strength after the heat test (heat-resistant peel strength) was 400 N / m or higher.

(B) Etchability and amount of metal residue For evaluation of etchability, a resin film metal film laminated substrate was cut into 3 cm × 3 cm, immersed in a chemical etching solution for 2 minutes, washed with water, and dried. Whether or not the metal layer remains undissolved on the insulating resin film was visually confirmed. If it remained clearly, it was determined that wiring processing using only the chemical etching solution was impossible. On the other hand, when it is difficult to judge by visual confirmation or when the undissolved residue cannot be confirmed, the insulating resin film A from which the metal layer is removed and the surface is exposed is subjected to microwave decomposition in order to measure the amount of metal residue after etching. Dissolve in a solution consisting of 5 ml of nitric acid and 1 ml of hydrogen peroxide in the apparatus, and quantitatively analyze the metal components in the obtained solution by ICP-MS (high frequency induction plasma emission spectroscopy / mass spectrometry), and the amount of metal residue (metal layer) The total amount of B and metal layer C) was measured.

(C) Insulation reliability The insulation reliability was evaluated according to the JPCA-ET04 standard.
Measurement sample was formed by peel strength measurement and the subtractive method in the same manner the comb lines of 40μm pitch shown in FIG. 3 for the resin film metal layer laminated substrate (line width 20 [mu] m, the space width 20 [mu] m). In the comb-shaped wiring, the length of the overlapping margin (10) of the comb-shaped conductor was 20 mm, and the gap (11a, 11b) between the tip of the comb-shaped conductor and the short bar was 5 mm. A potential difference of 60 V DC was applied between the wirings, and the insulation resistance value was measured with a migration tester (trade name: MIG-87, manufactured by IMV) at a temperature of 85 ° C. and a relative humidity of 85% for 1000 hours. The time when the resistance value was 10 ⁶ Ω or less was judged as a short circuit failure, and if it was 10 ⁶ Ω or more even after 1000 hours, it was judged as acceptable.

A polyimide film having a thickness of 38 μm (product name “Kapton 150EN” manufactured by Toray DuPont Co., Ltd.) was placed in a sputtering apparatus, evacuated to 1 × 10 ⁻¹ Pa, and then heated with an infrared heater. After the moisture in the film was removed, the film was evacuated to 1 × 10 ⁻⁴ Pa. Subsequently, Ar gas was introduced to maintain the pressure in the apparatus at 0.3 Pa, and a 10 nm thick Ni-7 mass% Cr layer and a 10 nm thick Ni-18 mass% Cr-10 mass% were formed on one side of the polyimide film by sputtering. An Mo layer and a 0.1 μm thick copper coating layer were sequentially formed, and then taken out from the sputtering apparatus. Subsequently, a copper layer having a thickness of 8 μm was formed on the copper coating layer by electroplating to obtain an insulating resin film metal film laminate 1.
A peel strength measurement sample and an insulation reliability measurement sample were prepared from the obtained resin film metal film laminated substrate 1 and subjected to each test.

The initial peel strength was 654 N / m, and the heat-resistant peel strength was 576 N / m. In addition, an insulation reliability test was conducted on three samples, and all of them were good in that they maintained a resistance of 10 ⁶ Ω or more even after 1000 hours.
Evaluation of the etching property, cut a resin film metal layer laminated substrate 1 in 3 cm × 3 cm, a solution of ferric chloride as a chemical etching solution at (specific gravity 40 ° Baume, the temperature 43 ° C.) for 2 minutes etched where visual observation insulating resin All metal layers on the film were dissolved. Further, the metal component slightly remaining on the surface layer of the insulating resin film is dissolved in a solution composed of 5 ml of nitric acid and 1 ml of hydrogen peroxide using a microwave decomposition apparatus, and the metal component in the obtained solution is obtained by ICP-MS. As a result of quantitative analysis, it was as good as 0.034 μg / cm ² .
The results are summarized in Table 1.

The resin layer metal film laminated substrate 2 obtained by forming a metal film by using Ni-7 mass% Cr with a film thickness of 3 nm for the metal layer B and using Ni-20 mass% Cr with a film thickness of 10 nm for the metal layer C is used. Except that, a sample was prepared and tested in the same manner as in Example 1. The results are shown in Table 1.

Example except that the metal layer B is made of Ni having a film thickness of 5 nm, and the resin film metal film laminated substrate 3 obtained by forming a metal film using Ni-20 mass% Cr having a film thickness of 20 nm on the metal layer C is used. Samples were prepared and tested in the same manner as in No. 1, and the results are shown in Table 1.

Resin film metal film laminated substrate obtained by forming a metal film using Ni-7 mass% Cr with a thickness of 20 nm and a metal film using Ni-18 mass% Cr-10 mass% Mo with a thickness of 10 nm on the metal layer C Samples were prepared and tested in the same manner as in Example 1 except that 4 was used, and the results are shown in Table 1.

Resin film metal film laminated substrate obtained by forming metal layer B with Ni-7 mass% Cr with a film thickness of 15 nm and forming metal film with Ni-18 mass% Cr-10 mass% Mo with a film thickness of 5 nm on metal layer C Samples were prepared and tested in the same manner as in Example 1 except that 5 was used, and the results are shown in Table 1.

Use the resin film metal film laminated substrate 6 obtained by forming the metal layer B with Ni-14 mass% Cr having a film thickness of 5 nm and forming a metal film with Ni-20 mass% Cr having a film thickness of 20 nm on the metal layer C. Except for the above, a sample was prepared in the same manner as in Example 1, and each test was performed. The results are shown in Table 1.

Use the resin film metal film laminated substrate 7 obtained by forming the metal layer B with Ni-7 mass% Cr having a film thickness of 15 nm and forming a metal film with Ni-40 mass% Cr having a film thickness of 25 nm on the metal layer C. Except for the above, a sample was prepared in the same manner as in Example 1, and each test was performed. The results are shown in Table 1.

Use the resin film metal film laminated substrate 8 obtained by forming the metal layer B with Ni-7 mass% Cr having a thickness of 10 nm and forming a metal film with Ni-70 mass% Cr having a thickness of 5 nm on the metal layer C. Except for the above, a sample was prepared in the same manner as in Example 1, and each test was performed. The results are shown in Table 1.

Resin film metal film obtained by forming metal layer B using Ni-5.6 mass% Cr-20 mass% Mo with a film thickness of 10 nm and forming metal film with metal layer C using Ni-20 mass% Cr with a film thickness of 10 nm Except for using the laminated substrate 9, a sample was prepared and each test was performed in the same manner as in Example 1, and the results are shown in Table 1.

Use a resin film metal film laminated substrate 10 obtained by forming a metal film with a metal layer B of Ni-13 mass% V with a film thickness of 10 nm and using Ni-20 mass% Cr with a film thickness of 10 nm on the metal layer C. Except for the above, a sample was prepared in the same manner as in Example 1, and each test was performed. The results are shown in Table 1.

A resin film metal film laminated substrate 11 obtained by forming a metal film using a metal layer B of Ni-7.5 mass% Ti with a thickness of 10 nm and a metal layer C using Ni-20 mass% Cr with a thickness of 10 nm. A sample was prepared in the same manner as in Example 1 except that it was used, and each test was performed. The results are shown in Table 1.

A chemical etching solution for evaluating the etching property of the resin film metal film laminated substrate 1 is an aqueous hydrochloric acid cupric chloride solution (HCl concentration: 1 mol / l, CuCl2: specific gravity 1.3, ORP: 580 mV, temperature: 40 ° C.). A sample was prepared in the same manner as in Example 1 except that was used, and each test was performed. The results are shown in Table 1.
(Comparative Example 1)

The resin film metal film laminated substrate 13 obtained by forming the metal layer B with Ni-18 mass% Cr-10 mass% Mo with a thickness of 10 nm and using Ni-7 mass% Cr with a thickness of 10 nm on the metal layer C is used. Except for this, a sample was prepared and tested in the same manner as in Example 1, and the results are shown in Table 1.
(Comparative Example 2)

Implementation is performed except that the metal layer B is Ni-18 mass% Cr-10 mass% Mo with a film thickness of 20 nm, and the resin film metal film laminated substrate 14 obtained by forming the copper coating layer D without providing the metal layer C is used. Samples were prepared and tested in the same manner as in Example 1, and the results are shown in Table 1.
(Comparative Example 3)

Example 1 except that the metal layer B is Ni-20 mass% Cr with a film thickness of 20 nm and the resin film metal film laminated substrate 15 obtained by forming the copper coating layer D without providing the metal layer C is used. Samples were prepared and tested, and the results are shown in Table 1.
(Comparative Example 4)

Example 1 except that the metal layer B is Ni-7 mass% Cr with a film thickness of 10 nm, and the resin film metal film laminated substrate 16 obtained by forming the copper coating layer D without providing the metal layer C is used. Samples were prepared and tested, and the results are shown in Table 1.
(Comparative Example 5)

The resin layer metal film laminated substrate 17 obtained by forming the metal layer B with Ni-7 mass% Cr having a film thickness of 2 nm and forming a metal film with Ni-20 mass% Cr having a film thickness of 15 nm on the metal layer C is used. Except for the above, a sample was prepared in the same manner as in Example 1, and each test was performed. The results are shown in Table 1.
(Comparative Example 6)

Resin film metal film laminated substrate obtained by forming a metal film using a Ni-7 mass% Cr alloy having a thickness of 10 nm and a metal layer C using Ni-18 mass% Cr-10 mass% Mo having a thickness of 3 nm. A sample was prepared in the same manner as in Example 1 except that 18 was used, and each test was performed. The results are shown in Table 1.

(Reference example)
Use a resin film metal film laminated substrate 19 obtained by forming a metal film using a Ni-7 mass% Cr alloy with a thickness of 5 nm and a metal layer C using Ni-20 mass% Cr with a thickness of 100 nm on the metal layer C. Except for the above, a sample was prepared in the same manner as in Example 1, and an etching test was performed. The results are shown in Table 1.

  As is clear from Table 1, in Invention Examples 1 to 12 produced in Examples 1 to 12, a metal layer B having a chromium content of less than 15 mass% was formed on the surface of the insulating resin film A, and a chromium layer was formed on the surface of the metal layer B. A printed wiring board in which a metal layer C with a content of 15 mass% or more is laminated with a copper coating layer on the surface of the metal layer C, has a good peel strength, has few metal residues after etching, and has high insulation reliability. I can see that

  On the other hand, in Comparative Example 1, the chromium content of the metal layer B exceeds 15 mass%, and the chromium content of the metal layer C is less than 15 mass%. Since the chromium content of the metal layer B exceeds 15 mass%, the metal residue after etching can be visually observed, and it can be seen that the insulation reliability cannot be ensured.

Since Comparative Example 2 is a base metal layer of only the metal layer B having a chromium content exceeding 15 mass%, the metal residue after etching can be visually observed as in Comparative Example 1, and the insulation reliability cannot be ensured. Recognize. In Comparative Example 3, as in Comparative Example 2, the base metal layer was formed only from the metal layer B. In the visual observation of the etching property, it was observed that the surface of the polyimide film was exposed. When the amount of residue is measured, it exceeds 0.15 μg / cm ² , indicating that the insulation reliability cannot be ensured.

  In Comparative Example 4, the chromium content of the metal layer B is 7 mass%, and the etching property and the amount of metal residue are good. However, since the base metal layer is composed only of the metal layer B, it is understood that the insulation reliability cannot be ensured. .

In Comparative Example 5, the chromium contents of the metal layer B and the metal layer C are within the scope of the claims of the present invention, but the metal layer B has a film thickness of 2 nm. Residue amount is 0.15 μg / cm ^2, and insulation reliability cannot be ensured. In Comparative Example 6, the chromium content of metal layer B and metal layer C is within the scope of the present invention. Since the film thickness is 3 nm, it can be seen that the insulation reliability cannot be secured.

In the reference example, the chromium content of the metal layer B and the metal layer C is within the scope of the claims of the present invention, and only the thickness of the metal layer C is 100 nm, which is significantly thicker than usual. It can be seen that the properties are good and the amount of metal residue is as small as 0.035 μg / cm ² .

It is sectional drawing of the resin film metal film laminated body used for the printed wiring board of this invention. It is a figure which shows the relationship between the chromium amount of a nickel-chromium alloy, and the amount of etching residues. It is the schematic of the comb-tooth-like wiring used for insulation reliability evaluation.

A Insulating resin film A
B Metal layer B
C Metal layer C
D Copper coating layer D
1a, 1b Short bar 2a, 2b Comb-shaped conductor 10a, 10b Comb wiring

Claims (12)

A conductive wiring is formed by selectively removing unnecessary portions of the metal film of the resin film metal film laminated substrate in which the metal film is laminated on at least one surface of the insulating resin film A without using an adhesive by chemical etching. Printed wiring board,
A metal layer B made of nickel or a nickel-chromium alloy containing 70% by mass or more of nickel and less than 15% by mass of chromium laminated on the surface of the insulating resin film A.
A metal layer made of an alloy containing nickel and containing 15 mass% or more of chromium, laminated on the surface of the metal layer B, having a thickness of 5 nm to 37 nm, or 5 nm or more and a total of 40 nm or less with the metal layer B C
It is composed of a copper coating layer D having a thickness of 10 nm to 35 μm laminated on the surface of the metal layer C,
An unnecessary portion of the metal film is selectively removed using only a chemical etching solution for etching the copper coating layer D. The insulating resin film after the conductor wiring made of the metal film in which the metal layer B, the metal layer C, and the copper coating layer D are sequentially laminated is chemically etched with a ferric chloride aqueous solution or a hydrochloric acid acidic cupric chloride aqueous solution. ^2. The printed wiring board according to claim 1, wherein the amount of the metal remaining on A is 0.13 μg / cm ² or less per unit area of the insulating resin film A. 3.   The metal layer B contains 13 mass% or less of vanadium, 8 mass% or less of titanium, 20 mass% or less of molybdenum, the remaining nickel or nickel of 70 mass% or more, and a nickel-chromium alloy containing less than 15 mass% of chromium and 1 mass% or less. The printed wiring board according to claim 1, wherein the printed wiring board is made of unavoidable impurities and has a thickness of 3 to 20 nm.   The metal layer C contains 15 mass% or more of chromium, 0.01 to 85 mass% of nickel, and an alloy composed of unavoidable impurities of 1 mass% or less, or 15 mass% or more of chromium, 0.01 to 85 mass% of nickel, molybdenum The printed wiring board according to any one of claims 1 to 3, wherein the printed wiring board is an alloy composed of inevitable impurities of 0.01 mass% or less.   The printed wiring board according to claim 1, wherein the chemical etching solution does not contain manganese and a cyanide compound.   The printed wiring board according to any one of claims 1 to 3, wherein the chemical etching solution is an aqueous ferric chloride solution or an aqueous hydrochloric acid cupric chloride solution.   The insulating resin film A is at least one selected from polyimide film, polyamide film, polyester film, polytetrafluoroethylene film, polyphenylene sulfide film, polyethylene naphthalate film, and liquid crystal polymer film. It is a resin film, The printed wiring board of Claim 1 or 2 characterized by the above-mentioned. Conductive by selectively removing unnecessary portions of the metal film by chemically etching the metal film of the resin film metal film laminated substrate in which the metal film is laminated on at least one surface of the insulating resin film A without using an adhesive. A method of manufacturing a printed wiring board on which wiring is formed,
The resin film metal layer laminated substrate, the nickel on the surface of the insulating resin film A, or nickel 70 mass% or more, nickel containing less than 15 mass% of chromium - a metallic layer B made of chromium alloy was formed by dry plating method, Next, the surface of the metal layer B is made of an alloy of 15 mass% or more of chromium and nickel, or an alloy of 15 mass% or more of chromium, nickel and molybdenum, and has a film thickness of 5 nm to 37 nm, or 5 nm or more and a metal. After the metal layer C having a total of 40 nm or less with the layer B is formed by a dry plating method, a metal film in which a copper film layer D having a thickness of 10 nm to 35 μm is laminated on the surface of the metal layer C is formed, A conductive wiring is formed by selectively removing a metal film with one kind of etching solution. Method.   The method for manufacturing a printed wiring board according to claim 8, wherein the chemical etching solution does not contain manganese and a cyanide compound.   The method of manufacturing a printed wiring board according to claim 8, wherein the chemical etching solution is an aqueous ferric chloride solution or an aqueous hydrochloric acid cupric chloride solution.   9. The method of manufacturing a printed wiring board according to claim 8, wherein the copper coating layer D forms a copper layer by electroplating on the surface of the copper layer formed by dry plating. The method for manufacturing a printed wiring board according to claim 8 or 11, wherein the dry plating method is any one of a vacuum deposition method, a sputtering method, and an ion plating method.

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