JP5432357B1 - Surface-treated copper foil and laminated board, copper-clad laminated board, printed wiring board and electronic device using the same - Google Patents

Abstract

A surface-treated copper foil that is well bonded to a resin and has excellent transparency after the copper foil is removed by etching, a laminate using the same, a copper-clad laminate, a printed wiring board, and an electronic device Provide equipment.
A surface-treated copper foil in which roughened particles are formed on at least one surface by roughening treatment, and the copper foil is bonded to both surfaces of a polyimide resin substrate, and then etched on both surfaces. When removing the foil and laying the printed matter on which the line-shaped mark is printed under the exposed polyimide substrate, and photographing the printed matter with the CCD camera through the polyimide substrate, the image obtained by the photographing, In the observation point-lightness graph prepared by measuring the lightness of each observation point along the direction perpendicular to the direction in which the observed line-shaped mark extends, it occurs from the end of the mark to the portion where the mark is not present. The surface-treated copper foil whose difference (DELTA) B ((DELTA) B = Bt-Bb) of the top average value Bt and bottom average value Bb of a brightness curve is 40 or more.
[Selection] Figure 1

Description

  The present invention relates to a surface-treated copper foil and a laminate using the surface-treated copper foil, and in particular, a surface-treated copper foil suitable for a field where transparency of the remaining resin after etching the copper foil is required, and a laminate using the same. The present invention relates to a board, a copper clad laminate, a printed wiring board, and an electronic device.

  In a small electronic device such as a smartphone or a tablet PC, a flexible printed wiring board (hereinafter referred to as FPC) is adopted because of easy wiring and light weight. In recent years, with the enhancement of functions of these electronic devices, the signal transmission speed has been increased, and impedance matching has become an important factor in FPC. As a measure for impedance matching with respect to an increase in signal capacity, a resin insulation layer (for example, polyimide) serving as a base of an FPC has been increased in thickness. In addition, the demand for higher wiring density has further increased the number of FPC layers. On the other hand, processing such as bonding to a liquid crystal substrate and mounting of an IC chip is performed on the FPC, but the alignment at this time is the resin insulation remaining after etching the copper foil in the laminate of the copper foil and the resin insulating layer The visibility of the resin insulation layer is important because it is performed through a positioning pattern that is visible through the layer.

  Moreover, the copper clad laminated board which is a laminated board of copper foil and a resin insulating layer can also be manufactured even if it uses the rolled copper foil by which roughening plating was given to the surface. This rolled copper foil usually uses tough pitch copper (oxygen content of 100 to 500 ppm by weight) or oxygen-free copper (oxygen content of 10 ppm by weight or less) as a raw material, and after hot rolling these ingots, It is manufactured by repeating cold rolling and annealing to a thickness.

As such a technique, for example, in Patent Document 1, a polyimide film and a low-roughness copper foil are laminated, and a light transmittance at a wavelength of 600 nm of the film after copper foil etching is 40% or more, a haze value. An invention relating to a copper clad laminate having (HAZE) of 30% or less and an adhesive strength of 500 N / m or more is disclosed.
Further, Patent Document 2 has an insulating layer in which a conductive layer made of electrolytic copper foil is laminated, and the light transmittance of the insulating layer in the etching region when the circuit is formed by etching the conductive layer is 50% or more. In a flexible printed wiring board for chip-on-flex (COF), the electrolytic copper foil has a rust-proofing layer made of a nickel-zinc alloy on an adhesive surface bonded to an insulating layer, and the surface roughness (Rz) of the adhesive surface ) Is 0.05 to 1.5 μm, and the specular gloss at an incident angle of 60 ° is 250 or more, and an invention relating to a flexible printed wiring board for COF is disclosed.
Moreover, in patent document 3, in the processing method of the copper foil for printed circuits, after the roughening process by copper-cobalt-nickel alloy plating on the surface of copper foil, a cobalt-nickel alloy plating layer is formed, and also zinc-nickel An invention relating to a method for treating a copper foil for printed circuit, characterized by forming an alloy plating layer is disclosed.

JP 2004-98659 A WO2003 / 096776 Japanese Patent No. 2849059

In Patent Document 1, a low-roughness copper foil obtained by improving adhesion with an organic treatment agent after blackening treatment or plating treatment is broken due to fatigue in applications where flexibility is required for a copper-clad laminate. May be inferior in resin transparency.
Moreover, in patent document 2, the roughening process is not made and the adhesive strength of copper foil and resin is low and inadequate in uses other than the flexible printed wiring board for COF.
Furthermore, in the processing method described in Patent Document 3, Cu-Co-Ni fine processing on the copper foil was possible, but the resin after bonding the copper foil with the resin and removing it by etching was excellent. Transparency is not realized.
The present invention provides a surface-treated copper foil that adheres well to a resin and is excellent in resin transparency after removing the copper foil by etching, a laminate using the same, a copper-clad laminate, a printed wiring board, and Provide electronic equipment.

  As a result of intensive studies, the inventors have placed a printed matter with a mark on the polyimide substrate from which the copper foil has been bonded and removed, and the mark portion taken by the CCD camera through the polyimide substrate. Paying attention to the lightness curve near the mark end drawn in the observation point-lightness graph obtained from the image of the above, controlling the lightness curve is not affected by the type of substrate resin film or the thickness of the substrate resin film Furthermore, it has been found that the resin transparency after the copper foil is removed by etching is affected.

  The present invention completed on the basis of the above knowledge, in one aspect, is a surface-treated copper foil in which roughened particles are formed on at least one surface by a roughening treatment, and the copper foil is disposed on both sides of a polyimide resin substrate. Then, the copper foils on both sides are removed by etching, and a printed matter on which a line-shaped mark is printed is laid under the exposed polyimide substrate, and the printed matter is photographed with a CCD camera through the polyimide substrate. In the observation point-brightness graph, the image obtained by the photographing was prepared by measuring the lightness of each observation point along the direction perpendicular to the direction in which the observed line-shaped mark extends. The difference ΔB (ΔB = Bt−Bb) between the top average value Bt and the bottom average value Bb of the brightness curve generated from the end portion of the mark to the portion without the mark is 40 or more. It is the surface-treated copper foil which is the top.

  In another embodiment of the surface-treated copper foil according to the present invention, a difference ΔB (ΔB = Bt−) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the mark to a portion without the mark. Bb) is 50 or more.

  In still another embodiment of the surface-treated copper foil according to the present invention, a difference ΔB (ΔB = Bt) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the mark to a portion without the mark. -Bb) is 60 or more.

In still another embodiment of the surface-treated copper foil according to the present invention, in the observation point-lightness graph, a value indicating a position of an intersection closest to the line-shaped mark among the intersections of the lightness curve and Bt is set. t1 indicates the position of the intersection closest to the line-shaped mark among the intersections of the lightness curve and 0.1ΔB in the depth range from the intersection of the lightness curve and Bt to 0.1ΔB with reference to Bt. When the value is t2, Sv defined by the following formula (1) is 3.5 or more.

    In still another embodiment of the surface-treated copper foil according to the present invention, Sv defined by the formula (1) in the brightness curve is 3.9 or more.

  In still another embodiment of the surface-treated copper foil according to the present invention, Sv defined by the formula (1) in the brightness curve is 5.0 or more.

  In yet another embodiment of the surface-treated copper foil according to the present invention, the TD average roughness Rz of the roughened surface is 0.30 to 0.80 μm, and the roughened surface MD has a 60 ° gloss. The ratio A / B between the surface area A of the roughened particles and the area B obtained when the roughened particles are viewed in plan from the copper foil surface side is 1.90-2. .40.

  In still another embodiment of the surface-treated copper foil according to the present invention, the 60-degree glossiness of the MD is 90 to 250%.

  In still another embodiment of the surface-treated copper foil according to the present invention, the average roughness Rz of the TD is 0.35 to 0.60 μm.

  In another embodiment of the surface-treated copper foil which concerns on this invention, said A / B is 2.00-2.20.

  In still another embodiment of the surface-treated copper foil according to the present invention, the ratio C of 60 ° gloss of MD and 60 ° gloss of TD on the roughened surface (C = (60 ° gloss of MD)) / (60 degree gloss of TD)) is 0.80 to 1.40.

  In still another embodiment of the surface-treated copper foil according to the present invention, the ratio C of 60 ° gloss of MD and 60 ° gloss of TD on the roughened surface (C = (60 ° gloss of MD)) / (60 degree gloss of TD)) is 0.90 to 1.35.

  In still another aspect, the present invention is a laminated plate configured by laminating the surface-treated copper foil of the present invention and a resin substrate.

  In still another aspect, the present invention is a printed wiring board using the surface-treated copper foil of the present invention.

  In still another aspect, the present invention is an electronic device using the printed wiring board of the present invention.

  In yet another aspect, the present invention provides a printed wiring board including an insulating resin substrate and a surface-treated copper foil that is laminated on the insulating substrate from the surface side where the surface treatment is performed and a copper circuit is formed. Then, when the copper circuit is photographed with a CCD camera through the insulating resin substrate laminated from the surface side where the surface treatment is performed, the copper circuit observed for the image obtained by the photographing is In the observation point-lightness graph prepared by measuring the lightness at each observation point along the direction perpendicular to the extending direction, the top average value Bt of the lightness curve generated from the end of the copper circuit to the portion without the copper circuit And the bottom average value Bb is a printed wiring board having a difference ΔB (ΔB = Bt−Bb) of 40 or more.

  In still another aspect, the present invention provides a copper-clad laminate including an insulating resin substrate and a surface-treated copper foil laminated on the insulating substrate from the surface side on which the surface treatment is performed. When the surface-treated copper foil of the tension laminate is made into a line-shaped surface-treated copper foil by etching, and taken with a CCD camera through the insulating resin substrate laminated from the surface side where the surface treatment is performed, In the observation point-brightness graph, which was prepared by measuring the brightness for each observation point along the direction perpendicular to the direction in which the line-shaped surface-treated copper foil was stretched, for the image obtained by the photographing, A difference ΔB (ΔB = Bt−Bb) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the line-shaped surface-treated copper foil to a portion where the line-shaped surface-treated copper foil is not present is 40 or more. It is the copper clad laminated board which is the top.

  In still another aspect, the present invention is an electronic device using the printed wiring board of the present invention.

  In still another aspect, the present invention is a printed wiring board using the copper clad laminate of the present invention.

  In still another aspect, the present invention is an electronic device using the copper clad laminate of the present invention.

  In still another aspect, the present invention is a method of manufacturing a printed wiring board in which two or more printed wiring boards are connected by connecting two or more printed wiring boards of the present invention.

  In yet another aspect, the present invention includes a step of connecting at least one printed wiring board of the present invention and another printed wiring board of the present invention or a printed wiring board not corresponding to the printed wiring board of the present invention, This is a method for manufacturing a printed wiring board in which two or more printed wiring boards are connected.

  In still another aspect of the present invention, a plug in which at least one printed wiring board of the present invention is connected is provided.

  According to the present invention, a surface-treated copper foil that adheres well to a resin and is excellent in transparency of a resin after the copper foil is removed by etching, a laminate using the same, a copper-clad laminate, and a printed wiring A board and an electronic device can be provided.

It is a schematic diagram which defines Bt and Bb. It is a schematic diagram which defines t1, t2, and Sv. It is a schematic diagram showing the structure of an imaging device and the measuring method of the inclination of a lightness curve in the case of evaluation of the lightness curve inclination. It is a SEM observation photograph of the copper foil surface of (a) comparative example 1 in the case of Rz evaluation. It is a SEM observation photograph of the copper foil surface of (b) comparative example 3 in the case of Rz evaluation. It is a SEM observation photograph of the copper foil surface of (c) comparative example 5 in the case of Rz evaluation. It is a SEM observation photograph on the surface of copper foil of (d) comparative example 6 in the case of Rz evaluation. (E) It is a SEM observation photograph of the copper foil surface of Example 1 in the case of Rz evaluation. (F) It is a SEM observation photograph of the copper foil surface of Example 2 in the case of Rz evaluation.

[Form and manufacturing method of surface-treated copper foil]
The copper foil used in the present invention is useful for a copper foil used by making a laminate by bonding to a resin substrate and removing it by etching.
The copper foil used in the present invention may be either an electrolytic copper foil or a rolled copper foil. Usually, the surface of the copper foil that adheres to the resin substrate, that is, the roughened surface, has a fist-like electric surface on the surface of the copper foil after degreasing in order to improve the peel strength of the copper foil after lamination. A roughening process is carried out to wear. Although the electrolytic copper foil has irregularities at the time of manufacture, the irregularities are further increased by enhancing the convex portions of the electrolytic copper foil by roughening treatment. In the present invention, this roughening treatment can be performed by copper-cobalt-nickel alloy plating, copper-nickel-phosphorus alloy plating, or the like. Ordinary copper plating or the like may be performed as a pretreatment before roughening, and ordinary copper plating or the like may be performed as a finishing treatment after roughening in order to prevent electrodeposits from dropping off. The content of treatment may be somewhat different between the rolled copper foil and the electrolytic copper foil .
Contact name the rolled copper foil according to the present invention Ag, Sn, In, Ti, Zn, Zr, Fe, P, Ni, Si, Te, Cr, Nb, V, copper alloys containing elements one or more of such B Foil is also included. When the concentration of the above elements increases (for example, 10% by mass or more in total), the conductivity may decrease. The conductivity of the rolled copper foil is preferably 50% IACS or more, more preferably 60% IACS or more, and still more preferably 80% IACS or more.

Also shows the production conditions of Ru electrodeposition Kaidohaku for use in the present invention are shown below.
<Electrolyte composition>
Copper: 90-110 g / L
Sulfuric acid: 90-110 g / L
Chlorine: 50-100ppm
Leveling agent 1 (bis (3sulfopropyl) disulfide): 10 to 30 ppm
Leveling agent 2 (amine compound): 10 to 30 ppm
As the amine compound, an amine compound having the following chemical formula can be used.

(In the above chemical formula, R ₁ and R ₂ are selected from the group consisting of a hydroxyalkyl group, an ether group, an aryl group, an aromatic substituted alkyl group, an unsaturated hydrocarbon group, and an alkyl group.)

<Production conditions>
Current density: 70 to 100 A / dm ²
Electrolyte temperature: 50-60 ° C
Electrolyte linear velocity: 3-5 m / sec
Electrolysis time: 0.5 to 10 minutes

Copper as roughening treatment - cobalt - nickel alloy plating, by electrolytic plating, coating weight is to be the 15~40mg / dm ² of copper -100~3000μg / dm ² of cobalt -100~1500μg / dm ² of nickel It can be carried out so as to form a ternary alloy layer. If the amount of deposited Co is less than 100 μg / dm ² , the heat resistance may deteriorate and the etching property may deteriorate. When the amount of Co deposition exceeds 3000 μg / dm ² , it is not preferable when the influence of magnetism must be taken into account, etching spots may occur, and acid resistance and chemical resistance may deteriorate. If the Ni adhesion amount is less than 100 μg / dm ² , the heat resistance may deteriorate. On the other hand, when the Ni adhesion amount exceeds 1500 μg / dm ² , the etching residue may increase. A preferable Co adhesion amount is 1000 to 2500 μg / dm ² , and a preferable nickel adhesion amount is 500 to 1200 μg / dm ² . Here, the etching stain means that Co remains without being dissolved when etched with copper chloride, and the etching residue means that Ni remains without being dissolved when alkaline etching is performed with ammonium chloride. It means that.

Such ternary copper - cobalt - general bath and plating conditions for forming the nickel alloy plating are as follows:
Plating bath composition: Cu 10-20 g / L, Co 1-10 g / L, Ni 1-10 g / L
pH: 1-4
Temperature: 30-50 ° C
Current density D _k : 25 to 45 A / dm ²
Plating time: 0.2 to 3.0 seconds
Further, as the roughening treatment, plating treatment using the following copper-nickel-phosphorus alloy plating bath can be performed.
Plating bath composition: Cu 20 g / L, Ni 5 g / L, P 1 g / L
pH: 2
Temperature: 30 ° C
Current density D _k : 35 A / dm ²
Plating time: 1 second
Moreover, as a roughening process, the following plating process using the copper-nickel-cobalt-tungsten alloy plating bath can be performed.
Plating bath composition: Cu 5 g / L, Ni 16 g / L, Co 16 g / L, W 1 g / L
pH: 3
Temperature: 35 ° C
Current density D _k : 35 A / dm ²
Plating time: 0.8 seconds
Further, as the roughening treatment, plating treatment using the following copper-nickel-molybdenum-phosphorus alloy plating bath can be performed.
Plating bath composition: Cu 10 g / L, Ni 10 g / L, Mo 2 g / L, P 1 g / L
pH: 3
Temperature: 35 ° C
Current density D _k : 40 A / dm ²
Plating time: 0.5 seconds

After the roughening treatment, a cobalt-nickel alloy plating layer of nickel having an adhesion amount of 200 to 3000 μg / dm ² and cobalt-100 to 700 μg / dm ² can be formed on the roughened surface. This treatment can be regarded as a kind of rust prevention treatment in a broad sense. This cobalt-nickel alloy plating layer needs to be performed to such an extent that the adhesive strength between the copper foil and the substrate is not substantially reduced. If the amount of cobalt adhesion is less than 200 μg / dm ² , the heat-resistant peel strength is lowered, and the oxidation resistance and chemical resistance may be deteriorated. As another reason, if the amount of cobalt is small, the treated surface becomes reddish, which is not preferable. When the amount of cobalt deposition exceeds 3000 μg / dm ² , it is not preferable when the influence of magnetism must be taken into account, and etching spots may occur, and acid resistance and chemical resistance may deteriorate. A preferable cobalt adhesion amount is 500 to 2500 μg / dm ² . On the other hand, if the nickel adhesion amount is less than 100 μg / dm ² , the heat-resistant peel strength is lowered, and the oxidation resistance and chemical resistance may be deteriorated. When nickel exceeds 1300 microgram / dm < ² >, alkali etching property will worsen. A preferable nickel adhesion amount is 200 to 1200 μg / dm ² .

In addition, cobalt - conditions of the nickel alloy plating are as follows:
Plating bath composition: Co 1-20 g / L, Ni 1-20 g / L
pH: 1.5-3.5
Temperature: 30-80 ° C
Current density D _k : 1.0 to 20.0 A / dm ²
Plating time: 0.5-4 seconds

According to the present invention, a zinc plating layer having an adhesion amount of 30 to 250 μg / dm ² is further formed on the cobalt-nickel alloy plating. If the zinc adhesion amount is less than 30 μg / dm ² , the heat deterioration rate improving effect may be lost. On the other hand, when the zinc adhesion amount exceeds 250 μg / dm ² , the hydrochloric acid deterioration rate may be extremely deteriorated. Preferably, the zinc adhesion amount is 30 to 240 μg / dm ² , more preferably 80 to 220 μg / dm ² .

Conditions of the zinc plating is as follows:
Plating bath composition: Zn 100 to 300 g / L
pH: 3-4
Temperature: 50-60 ° C
Current density D _k : 0.1 to 0.5 A / dm ²
Plating time: 1-3 seconds

  A zinc alloy plating layer such as zinc-nickel alloy plating may be formed instead of the zinc plating layer, and a rust prevention layer may be formed on the outermost surface by chromate treatment or application of a silane coupling agent. Good.

[Surface roughness Rz]
In the surface-treated copper foil of the present invention, it is preferable that roughened particles are formed on the surface of the copper foil by the roughening treatment, and that the average roughness Rz of TD on the roughened surface is 0.30 to 0.80 μm. . With such a configuration, the peel strength is increased and the resin is satisfactorily bonded to the resin, and the transparency of the resin after the copper foil is removed by etching is increased. As a result, alignment and the like when mounting an IC chip through a positioning pattern that is visible through the resin can be made easier. When the average roughness Rz of TD is less than 0.30 μm, the roughening treatment on the surface of the copper foil may be insufficient, and there may be a problem that the resin cannot be sufficiently adhered. On the other hand, if the average roughness Rz of TD is more than 0.80 μm, the unevenness of the resin surface after the copper foil is removed by etching may increase, resulting in a problem that the transparency of the resin becomes poor. There is a fear. The average TD roughness Rz of the roughened surface is more preferably 0.30 to 0.70 μm, still more preferably 0.35 to 0.60 μm, still more preferably 0.35 to 0.55 μm, and Even more preferred is 35 to 0.50 μm.

[Glossiness]
The glossiness at an incident angle of 60 degrees in the rolling direction (MD) of the roughened surface of the surface-treated copper foil greatly affects the transparency of the resin. That is, the greater the glossiness of the roughened surface, the better the transparency of the resin. For this reason, the surface-treated copper foil of the present invention preferably has a roughened surface with a glossiness of 80 to 350%, more preferably 90 to 300%, and even more preferably 90 to 250%. Preferably, it is 100 to 250%, and still more preferable.

Here, in order to on improvement effect of visibility of the invention, to control the roughness (Rz) and gloss of the TD process side of the surface of the copper foil before surface treatment. Specifically, the TD surface roughness (Rz) of the copper foil before the surface treatment is 0 . 30～0.80Myuemu, good Mashiku is 0.30～0.50Myuemu, gloss 3 50 to 800% at an incident angle of 60 degrees in the rolling direction (MD), good Mashiku at 500-800% If the current density is made higher than the conventional roughening treatment and the roughening treatment time is shortened, the incident angle in the rolling direction (MD) of the surface-treated copper foil after the surface treatment is 60 degrees. The glossiness is 90 to 350%. Such a copper foil can be produced by adjusting the oil film equivalent of rolling oil (high gloss rolling), or by chemical polishing such as chemical etching or electrolytic polishing in a phosphoric acid solution. Thus, it is easy to control the surface roughness (Rz) and the surface area of the copper foil after the treatment by setting the TD surface roughness (Rz) and the glossiness of the copper foil before the treatment within the above range. Can do.
Further, the copper foil before the roughening treatment preferably has an MD 60 degree gloss of 500 to 800%, more preferably 501 to 800%, and even more preferably 510 to 750%. . If the 60 degree glossiness of MD of the copper foil before the roughening treatment is less than 500%, the transparency of the resin may be poorer than the case of 500% or more. The problem that it becomes difficult may arise.
High gloss rolling can be performed by setting the oil film equivalent defined by the following formula to 13,000 to 24000 or less.
Oil film equivalent = {(rolling oil viscosity [cSt]) × (sheet feeding speed [mpm] + roll peripheral speed [mpm])} / {(roll biting angle [rad]) × (yield stress of material [kg / mm ² ])}
The rolling oil viscosity [cSt] is a kinematic viscosity at 40 ° C.
In order to set the oil film equivalent to 13,000 to 24,000, a known method such as using a low-viscosity rolling oil or slowing a sheet passing speed may be used.
Chemical polishing is performed over a long period of time using an etching solution such as sulfuric acid-hydrogen peroxide-water system or ammonia-hydrogen peroxide-water system at a concentration lower than usual.

  The ratio C (C = (60 degree gloss of MD) / (60 degree gloss of TD)) of the 60 degree gloss of MD and 60 degree gloss of TD on the roughened surface is 0.80 to 1. 40 is preferred. If the ratio C between the 60 ° glossiness of MD and the 60 ° glossiness of TD on the roughened surface is less than 0.80, the transparency of the resin may be lower than when the ratio C is 0.80 or more. . Further, if the ratio C is more than 1.40, the transparency of the resin may be lower than when the ratio C is 1.40 or less. The ratio C is more preferably 0.90 to 1.35, and even more preferably 1.00 to 1.30.

[Brightness curve]
The surface-treated copper foil of the present invention is bonded to both sides of a polyimide resin substrate, and then the copper foil on both sides is removed by etching, and a printed matter on which a line-shaped mark is printed is laid under the exposed polyimide substrate. Then, when the printed matter is photographed with a CCD camera through the polyimide substrate, the brightness at each observation point is measured along the direction perpendicular to the direction in which the observed line-shaped mark extends with respect to the image obtained by photographing. In the observation point-brightness graph produced in this way, the difference ΔB (ΔB = Bt−Bb) between the top average value Bt and the bottom average value Bb of the brightness curve generated from the end of the mark to the portion where the mark is not present is 40 or more. is there.
Further, the surface-treated copper foil of the present invention has a lightness curve, Bt, and a value indicating the position of the intersection closest to the line-shaped mark among the intersections of the brightness curve and Bt in the observation point-lightness graph. In the depth range from the intersection of Bt to 0.1ΔB, the value indicating the position of the intersection closest to the line-shaped mark among the intersections of the lightness curve and 0.1ΔB is t2. Sv defined by the following formula (1) is preferably 3.5 or more.
In the observation position-lightness graph, the horizontal axis represents position information (pixel × 0.1), and the vertical axis represents the value of brightness (gradation).
Here, “top average value Bt of the lightness curve”, “bottom average value Bb of the lightness curve”, and “t1”, “t2”, and “Sv” described later will be described with reference to the drawings.
FIGS. 1A and 1B are schematic views for defining Bt and Bb when the mark width is about 0.3 mm. When the mark width is about 0.3 mm, a V-shaped brightness curve may be obtained as shown in FIG. 1A, or a brightness curve having a bottom as shown in FIG. 1B. . In any case, the “top average value Bt of the lightness curve” indicates the average value of lightness when measured at 5 locations (a total of 10 locations on both sides) at 30 μm intervals from the positions 50 μm away from the end positions on both sides of the mark. . On the other hand, the “bottom average value Bb of the lightness curve” indicates the minimum value of lightness at the tip of the V-shaped valley when the lightness curve is V-shaped as shown in FIG. When it has the bottom of (b), the value of the center part of about 0.3 mm is shown.
FIG. 2 is a schematic diagram that defines t1, t2, and Sv. “T1 (pixel × 0.1)” is a value indicating an intersection point closest to the line-shaped mark among intersection points of the lightness curve and Bt and a position of the intersection point (value on the horizontal axis of the observation point-lightness graph) ). “T2 (pixel × 0.1)” is the line-shaped mark among the intersections of the lightness curve and 0.1ΔB in the depth range from the intersection of the lightness curve and Bt to 0.1ΔB with reference to Bt. And the value (the value on the horizontal axis of the observation point-brightness graph) indicating the position of the intersection closest to. At this time, regarding the slope of the brightness curve indicated by the line connecting t1 and t2, Sv (gradation / pixel × 0.1) calculated by 0.1 ΔB in the y-axis direction and (t1−t2) in the x-axis direction. ). One pixel on the horizontal axis corresponds to a length of 10 μm. Further, Sv is measured on both sides of the mark, and a small value is adopted. Further, when the shape of the lightness curve is unstable and there are a plurality of the “intersections between the lightness curve and Bt”, the intersection closest to the mark is adopted.
In the image taken by the CCD camera, the brightness is high at the portion where the mark is not attached, but the brightness decreases as soon as the end of the mark is reached. If the visibility of the polyimide substrate is good, such a lowered state of brightness is clearly observed. On the other hand, if the visibility of the polyimide substrate is poor, the lightness does not suddenly drop from “high” to “low” in the vicinity of the mark end, but the state of decline is slow and the state of lightness decline is unclear. End up.
Based on such knowledge, the present invention is based on such a polyimide substrate from which the surface-treated copper foil of the present invention is bonded and removed, and a mark printed matter is placed under the polyimide substrate and photographed with a CCD camera over the polyimide substrate. The brightness curve in the vicinity of the mark end drawn in the observation point-brightness graph obtained from the image is controlled. More specifically, the difference ΔB (ΔB = Bt−Bb) between the top average value Bt and the bottom average value Bb of the brightness curve generated from the end portion of the mark to the portion without the mark is 40 or more. According to such a configuration, the discrimination power of the mark over the polyimide by the CCD camera is improved without being affected by the type and thickness of the substrate resin. For this reason, it is possible to produce a polyimide substrate with excellent visibility, and the positioning accuracy by marking when performing a predetermined treatment on the polyimide substrate in an electronic substrate manufacturing process or the like is improved, thereby improving the yield. can get.
The ΔB (ΔB = Bt−Bb) is preferably 50 or more, and more preferably 60 or more. Sv is more preferably 3.9 or more, more preferably 4.5 or more, and more preferably 5.0 or more. The upper limit of ΔB is not particularly limited, but is, for example, 100 or less, 80 or less, or 70 or less. Further, the upper limit of Sv is not particularly limited, but is, for example, 15 or less and 10 or less. According to such a configuration, the boundary between the mark and the non-mark portion becomes clearer, the positioning accuracy is improved, the error due to the mark image recognition is reduced, and the alignment can be performed more accurately.

[Particle surface area]
The ratio A / B between the surface area A of the roughened particles and the area B obtained when the roughened particles are viewed in plan from the copper foil surface side greatly affects the transparency of the resin. That is, if the surface roughness Rz is the same, the smaller the ratio A / B, the better the transparency of the resin. For this reason, as for the surface-treated copper foil of this invention, it is preferable that the said ratio A / B is 1.90-2.40, and it is more preferable that it is 2.00-2.20.

  By controlling the current density and the plating time during particle formation, the particle morphology and formation density are determined, and the surface roughness Rz, glossiness, and particle area ratio A / B can be controlled.

  As described above, the ratio A / B between the surface area A of the roughened particles and the area B obtained when the roughened particles are viewed in plan view from the copper foil surface side is controlled to 1.90 to 2.40. The roughness of the roughened surface is controlled to 0.30 to 0.80 μm to eliminate extremely rough portions, while the glossiness of the roughened surface is increased. It can be as high as 80 to 350%. By performing such control, in the surface-treated copper foil of the present invention, the particle size of the roughened particles on the roughened surface can be reduced. The particle size of the roughened particles affects the resin transparency after the copper foil is removed by etching, but such control means that the particle size of the roughened particles is reduced within an appropriate range. Therefore, the resin transparency after removing the copper foil by etching becomes better, and the peel strength becomes better.

  The surface-treated copper foil of the present invention can be bonded to a resin substrate from the roughened surface side to produce a laminate. The resin substrate is not particularly limited as long as it has characteristics applicable to a printed wiring board or the like. For example, a paper base phenol resin, a paper base epoxy resin, a synthetic fiber cloth base epoxy resin for rigid PWB Glass cloth / paper composite base material epoxy resin, glass cloth / glass nonwoven fabric composite base material epoxy resin and glass cloth base material epoxy resin, etc. are used, polyester film, polyimide film, liquid crystal polymer (LCP) film, Teflon for FPC (Registered trademark) film or the like can be used.

In the case of the rigid PWB, a prepreg is prepared by impregnating a base material such as a glass cloth with a resin and curing the resin to a semi-cured state. It can be carried out by superposing a copper foil on the prepreg from the opposite surface of the coating layer and heating and pressing. In the case of FPC, it is laminated on a copper foil under high temperature and high pressure without using an adhesive on a substrate such as a polyimide film, or a polyimide precursor is applied, dried, cured, etc. A laminated board can be manufactured by performing.
The thickness of the polyimide base resin is not particularly limited, but generally 25 μm or 50 μm can be mentioned.

The laminate of the present invention can be used for various printed wiring boards (PWB) and is not particularly limited. For example, from the viewpoint of the number of layers of the conductor pattern, the single-sided PWB, the double-sided PWB, and the multilayer PWB (3 It is applicable to rigid PWB, flexible PWB (FPC), and rigid flex PWB from the viewpoint of the type of insulating substrate material. The electronic device of the present invention can be manufactured using such a printed wiring board.
The printed wiring board of the present invention is a printed wiring board composed of an insulating resin substrate and a surface-treated copper foil on which a copper circuit is formed by being laminated on the insulating substrate from the surface side where the surface treatment is performed. When a copper circuit is photographed with a CCD camera through an insulating resin substrate laminated from the surface side where the surface treatment is performed, the image obtained by photographing is perpendicular to the direction in which the observed copper circuit extends. In the observation point-lightness graph prepared by measuring the lightness at each observation point along a certain direction, the top average value Bt and the bottom average value Bb of the lightness curve generated from the end of the copper circuit to the portion without the copper circuit The difference ΔB (ΔB = Bt−Bb) is 40 or more. When such a printed wiring board is used, the printed wiring board can be positioned more accurately. Therefore, when one printed wiring board and another printed wiring board are connected, it is considered that the connection failure is reduced and the yield is improved. In addition, as a method of connecting one printed wiring board and another printed wiring board, connection via soldering or anisotropic conductive film (ACF), anisotropic conductive paste (Anisotropic Conductive Paste, A known connection method such as connection via ACP) or connection via a conductive adhesive can be used.
The copper clad laminate of the present invention is a copper clad laminate comprising an insulating resin substrate and a surface-treated copper foil laminated on the insulating substrate from the surface side where the surface treatment is performed, When the surface-treated copper foil of the tension laminate is made into a line-shaped surface-treated copper foil by etching, and taken with a CCD camera through the insulating resin substrate laminated from the surface side where the surface treatment is performed, In the observation point-brightness graph prepared for the obtained image, the brightness at each observation point was measured along a direction perpendicular to the direction in which the line-shaped surface-treated copper foil was observed. The difference ΔB (ΔB = Bt−Bb) between the top average value Bt and the bottom average value Bb of the brightness curve generated from the end of the treated copper foil to the portion where the line-shaped surface-treated copper foil is not present is 40 or more. When a printed wiring board is manufactured using such a copper-clad laminate, the printed wiring board can be positioned more accurately. Therefore, when one printed wiring board and another printed wiring board are connected, it is considered that the connection failure is reduced and the yield is improved. In addition, as a method of connecting one printed wiring board and another printed wiring board, connection via soldering or anisotropic conductive film (ACF), anisotropic conductive paste (Anisotropic Conductive Paste, A known connection method such as connection via ACP) or connection via a conductive adhesive can be used.
In the present invention, the “printed wiring board” includes a printed wiring board and a printed board on which components are mounted.

As Examples 1 to 30 and Comparative Examples 1 to 14, various copper foils were prepared, and plating treatment was performed on one surface under the conditions described in Table 1 as a roughening treatment.
After performing the roughening plating process described above, Examples 1 to 10, 12 to 27, and Comparative Examples 3, 4, 6, and 9 to 14 were subjected to the following plating process for forming a heat-resistant layer and a rust-proof layer. .
The conditions for forming the heat-resistant layer 1 are shown below.
Liquid composition: Nickel 5-20 g / L, cobalt 1-8 g / L
pH: 2-3
Liquid temperature: 40-60 degreeC
Current density: 5 to 20 A / dm ²
Coulomb amount: 10-20 As / dm ²
A heat-resistant layer 2 was formed on the copper foil provided with the heat-resistant layer 1. For Comparative Examples 5, 7, and 8, the rough plating treatment was not performed, and the heat-resistant layer 2 was directly formed on the prepared copper foil. The conditions for forming the heat-resistant layer 2 are shown below.
Liquid composition: nickel 2-30 g / L, zinc 2-30 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²
On the copper foil which gave the said heat-resistant layers 1 and 2, the antirust layer was further formed. The conditions for forming the rust preventive layer are shown below.
Liquid composition: potassium dichromate 1-10 g / L, zinc 0-5 g / L
pH: 3-4
Liquid temperature: 50-60 degreeC
Current density: 0 to ^{2 A} / dm ² (for immersion chromate treatment)
Coulomb amount: 0 to ^{2 As} / dm ² (for immersion chromate treatment)
On the copper foil which gave the said heat-resistant layers 1 and 2 and a rust prevention layer, the weathering layer was further formed. The formation conditions are shown below.
As a silane coupling agent having an amino group, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane (Examples 17, 24-27), N-2- (aminoethyl) -3-aminopropyltri Ethoxysilane (Examples 1 to 16), N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (Examples 18, 28, 29, 30), 3-aminopropyltrimethoxysilane (Example 19) 3-aminopropyltriethoxysilane (Examples 20 and 21), 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine (Example 22), N-phenyl-3-aminopropyltri Coating and drying were performed with methoxysilane (Example 23) to form a weather resistant layer. These silane coupling agents can be used in combination of two or more. Similarly, in Comparative Examples 1 to 14, coating and drying were performed with N-2- (aminoethyl) -3-aminopropyltrimethoxysilane to form a weather resistant layer.

In addition, the rolled copper foil was manufactured as follows. After manufacturing the copper ingot of the composition shown in Table 2 and performing hot rolling, annealing and cold rolling of a continuous annealing line at 300 to 800 ° C. were repeated to obtain a rolled sheet having a thickness of 1 to 2 mm. This rolled sheet was annealed in a continuous annealing line at 300 to 800 ° C. and recrystallized, and finally cold-rolled to the thickness shown in Table 2 to obtain a copper foil. “Tough pitch copper” in the “Type” column of Table 2 indicates tough pitch copper standardized in JIS H3100 C1100, and “Oxygen-free copper” indicates oxygen-free copper standardized in JIS H3100 C1020. “Tough pitch copper + Ag: 100 ppm” means that 100 mass ppm of Ag is added to tough pitch copper.
The electrolytic copper foil used was an electrolytic copper foil HLP foil manufactured by JX Nippon Mining & Metals. When electrolytic polishing or chemical polishing was performed, the plate thickness after electrolytic polishing or chemical polishing was described.
Table 2 lists the points of the copper foil preparation process before the surface treatment. “High gloss rolling” means that the final cold rolling (cold rolling after the final recrystallization annealing) was performed at the value of the oil film equivalent. “Normal rolling” means that the final cold rolling (cold rolling after the final recrystallization annealing) was performed at the oil film equivalent value described. “Chemical polishing” and “electropolishing” mean the following conditions.
“Chemical polishing” was performed using an etching solution of 1 to 3% by mass of H ₂ SO ₄ , 0.05 to 0.15% by mass of H ₂ O ₂ , and the remaining water, and the polishing time was 1 hour.
“Electropolishing” is a condition of phosphoric acid 67% + sulfuric acid 10% + water 23%, voltage 10 V / cm ² , and the time shown in Table 2 (when electropolishing for 10 seconds, the polishing amount is 1 to 2 μm. ).

Various evaluation was performed as follows about each sample of the Example and comparative example which were produced as mentioned above.
(1) Measurement of surface roughness (Rz);
Ten-point average roughness was measured on the roughened surface using a contact roughness meter Surfcorder SE-3C manufactured by Kosaka Laboratory Co., Ltd. in accordance with JIS B0601-1994. Measurement standard length 0.8mm, evaluation length 4mm, cut-off value 0.25mm, feed rate 0.1mm / sec. Perpendicular to rolling direction (in TD, in case of electrolytic copper foil, in foil passing direction) The measurement position was changed 10 times (perpendicularly), and the values for 10 measurements were obtained.
In addition, the surface roughness (Rz) was calculated | required similarly about the copper foil before surface treatment.

(2) Particle area ratio (A / B);
The surface area of the roughened particles was measured by a laser microscope. Using a laser microscope VK8500 manufactured by Keyence Co., Ltd., measuring the three-dimensional surface area A in an area B equivalent to 100 × 100 μm at a magnification of 2000 times the roughened surface (actual data: 9982.52 μm ² ), the three-dimensional surface area A ÷ Setting was performed by a method of setting a two-dimensional surface area B = area ratio (A / B).

(3) Glossiness;
Using Nippon Denshoku Industries Co., Ltd. gloss meter handy gloss meter PG-1 in accordance with JIS Z8741, rolling direction (MD, foil direction in the case of electrolytic copper foil) and direction perpendicular to the rolling direction (TD, In the case of an electrolytic copper foil, the roughened surface was measured at an incident angle of 60 degrees in a direction perpendicular to the direction of threading.
In addition, the glossiness was calculated | required similarly about the copper foil before surface treatment.

(4) Inclination of brightness curve Copper foil was bonded to both sides of polyimide film (Kaneka thickness 25 μm and 50 μm, Toray DuPont thickness 50 μm), and the copper foil was removed by etching (ferric chloride aqueous solution). Was made. In addition, about the copper foil which performed the roughening process, the surface which roughened the copper foil was bonded together to the above-mentioned polyimide film, and the above-mentioned sample film was produced. Subsequently, a printed material on which a line-shaped black mark is printed is laid under the sample film, and the printed material is photographed with a CCD camera through the sample film. In an observation point-lightness graph prepared by measuring the lightness at each observation point along a direction perpendicular to the extending direction, ΔB, t1, t2, and Sv were measured from the lightness curve. FIG. 3 is a schematic diagram showing the configuration of the photographing apparatus used at this time and the measurement method of the brightness curve.
Further, ΔB, t1, t2, and Sv were measured by the following photographing apparatus as shown in FIG.
The photographing device has a CCD camera, a stage (white) on which a polyimide substrate is placed with a marked paper underneath, an illumination power source that irradiates light onto the photographing portion of the polyimide substrate, and a paper with a mark to be photographed. A transporter (not shown) for transporting the evaluation polyimide substrate placed below onto the stage is provided. The main specifications of the camera are as follows:
・ Photographing device: Sheet inspection device Mujken manufactured by Nireco Corporation
CCD camera: 8192 pixels (160 MHz), 1024 gradation digital (10 bits)
・ Power supply for lighting: High-frequency lighting power supply (power supply unit x 2)
・ Lighting: Fluorescent lamp (30W)
For the lightness shown in FIG. 3, 0 means “black”, lightness 255 means “white”, and the gray level from “black” to “white” (black and white shading, gray scale) Is divided into 256 gradations for display.

(5) Visibility (resin transparency);
The copper foil was bonded to both surfaces of a polyimide film (Kaneka thickness 25 μm and 50 μm, Toray DuPont thickness 50 μm), and the copper foil was removed by etching (ferric chloride aqueous solution) to prepare a sample film. In addition, about the copper foil which performed the roughening process, the surface which roughened the copper foil was bonded together to the above-mentioned polyimide film, and the above-mentioned sample film was produced. A printed material (black circle with a diameter of 6 cm) was attached to one surface of the obtained resin layer, and the visibility of the printed material was judged from the opposite surface through the resin layer. “◎” indicates that the outline of the black circle of the printed material is clear when the length is 90% or more of the circumference, and “Clear” indicates that the outline of the black circle is clear when the length is 80% or more and less than 90% of the circumference. “O” (passed above), a black circle with a clear outline of 0 to less than 80% of the circumference and a broken outline were evaluated as “x” (failed).

(6) Peel strength (adhesive strength);
Based on PC-TM-650, the normal peel strength was measured with a tensile tester Autograph 100, and a normal peel strength of 0.7 N / mm or more could be used for laminated substrate applications.

(7) Solder heat resistance evaluation;
Copper foil was bonded to both surfaces of a polyimide film (Kaneka thickness 25 μm and 50 μm, Toray DuPont thickness 50 μm). In addition, about the copper foil which performed the roughening process, the surface which roughened the copper foil was bonded together to the above-mentioned polyimide film. About the obtained double-sided laminated board, the test coupon based on JISC6471 was created. The prepared test coupon was exposed to high temperature and high humidity of 85 ° C. and 85% RH for 48 hours, and then floated in a solder bath at 300 ° C. to evaluate solder heat resistance. After the solder heat resistance test, at the interface between the copper foil roughening surface and the polyimide resin adhesion surface, the area where the interface discolored due to blistering in an area of 5% or more of the copper foil area in the test coupon is x (failed), area When the color change was less than 5%, the case was evaluated as ◯, and the case where no color change occurred was evaluated as ◎.

(8) Yield Bond copper foil on both sides of polyimide film (Kaneka thickness 25 μm and 50 μm, Toray DuPont thickness 50 μm), etch copper foil (ferric chloride aqueous solution), L / S is 30 μm / An FPC having a circuit width of 30 μm was prepared. In addition, about the copper foil which performed the roughening process, the surface which roughened the copper foil was bonded together to the above-mentioned polyimide film. After that, an attempt was made to detect a 20 μm × 20 μm square mark with a CCD camera through polyimide. “◎” when 9 times or more out of 10 times can be detected, “◯” when 7 to 8 times can be detected, “△” when 6 times can be detected, and when 5 times or less can be detected. Is “×”.
The conditions and evaluation of each test are shown in Tables 1-5.

(Evaluation results)
Examples 1 to 30 all had good visibility, peel strength, solder heat resistance evaluation and yield.
Since Comparative Examples 1-4, 6, and 9-14 had a ΔB value of less than 40, the visibility was poor.
In Comparative Examples 5, 7, and 8, the visibility was excellent, but the substrate adhesion was poor. In Comparative Examples 1 to 14, the solder heat resistance evaluation was poor.
FIG. 4 shows (a) Comparative Example 1, (b) Comparative Example 3, (c) Comparative Example 5, (d) Comparative Example 6, (e) Example 1, and (f) Implementation in the above Rz evaluation. The SEM observation photograph of the copper foil surface of Example 2 is shown, respectively.

Claims (23)

A surface-treated copper foil in which roughened particles are formed by roughening treatment on at least one surface,
After laminating the copper foil on both sides of the polyimide resin substrate, the copper foil on both sides is removed by etching,
When a printed matter on which a line-shaped mark is printed is laid under the exposed polyimide substrate, and the printed matter is photographed with a CCD camera through the polyimide substrate,
For the image obtained by the photographing, an observation point-brightness graph prepared by measuring the brightness of each observation point along the direction perpendicular to the direction in which the observed line-shaped mark extends,
A surface-treated copper foil in which a difference ΔB (ΔB = Bt−Bb) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the mark to a portion without the mark is 40 or more.   2. The surface-treated copper according to claim 1, wherein a difference ΔB (ΔB = Bt−Bb) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the mark to a portion without the mark is 50 or more. Foil.   3. The surface-treated copper according to claim 2, wherein a difference ΔB (ΔB = Bt−Bb) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the mark to a portion without the mark is 60 or more. Foil. In the observation point-lightness graph, a value indicating the position of the intersection closest to the line-shaped mark among the intersections of the lightness curve and Bt is defined as t1, and the value of 0. 0 based on Bt from the intersection of the lightness curve and Bt. In the depth range up to 1ΔB, the value indicating the position of the intersection closest to the line-shaped mark among the intersections of the lightness curve and 0.1ΔB is defined by the following equation (1). The surface-treated copper foil according to any one of claims 1 to 3, wherein Sv is 3.5 or more.
  The surface-treated copper foil of Claim 4 from which Sv defined by (1) Formula in the said brightness curve becomes 3.9 or more.   The surface-treated copper foil according to claim 5, wherein Sv defined by the formula (1) in the brightness curve is 5.0 or more. Average roughness Rz of TD of the roughened surface is 0.30 to 0.80 μm, and 60 degree gloss of MD of the roughened surface is 80 to 350%,
The ratio A / B between the surface area A of the roughened particles and the area B obtained when the roughened particles are viewed in plan from the copper foil surface side is 1.90 to 2.40. The surface-treated copper foil in any one of.   The surface-treated copper foil according to claim 7, wherein the MD has a 60-degree glossiness of 90 to 250%.   The surface-treated copper foil according to claim 7 or 8, wherein the average roughness Rz of the TD is 0.35 to 0.60 µm.   Said A / B is 2.00-2.20, The surface-treated copper foil in any one of Claims 7-9.   The ratio C (C = (60 degree gloss of MD) / (60 degree gloss of TD)) of the 60 degree gloss of MD and 60 degree gloss of TD on the roughened surface is 0.80 to 1. It is 40, The surface-treated copper foil in any one of Claims 7-10.   The ratio C (C = (60 ° gloss of MD) / (60 ° gloss of TD)) of the 60 ° gloss of MD and 60 ° gloss of TD on the roughened surface is 0.90 to 1. The surface-treated copper foil according to claim 11, which is 35.   The laminated board comprised by laminating | stacking the surface-treated copper foil and resin substrate in any one of Claims 1-12.   The printed wiring board using the surface-treated copper foil in any one of Claims 1-12.   An electronic device using the printed wiring board according to claim 14. A printed wiring board composed of an insulating resin substrate and a surface-treated copper foil on which a copper circuit is formed, which is laminated on the insulating substrate from the surface side where surface treatment is performed,
When the copper circuit is photographed with a CCD camera through the insulating resin substrate laminated from the surface side where the surface treatment is performed,
For the image obtained by the photographing, in the observation point-lightness graph prepared by measuring the brightness for each observation point along the direction perpendicular to the direction in which the observed copper circuit extends,
A printed wiring board in which a difference ΔB (ΔB = Bt−Bb) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the copper circuit to a portion without the copper circuit is 40 or more. A copper-clad laminate composed of an insulating resin substrate and a surface-treated copper foil laminated on the insulating substrate from the surface side where surface treatment is performed,
The surface-treated copper foil of the copper-clad laminate was photographed with a CCD camera through the insulating resin substrate laminated from the surface side where the surface treatment was performed after making the surface-treated copper foil into a line-like surface by etching. When
For the image obtained by the photographing, an observation point-brightness graph prepared by measuring the brightness for each observation point along the direction perpendicular to the direction in which the observed surface-treated copper foil extends,
A difference ΔB (ΔB = Bt−Bb) between a top average value Bt and a bottom average value Bb of a brightness curve generated from an end portion of the line-shaped surface-treated copper foil to a portion where the line-shaped surface-treated copper foil is not present is 40. This is the copper-clad laminate.   The electronic device using the printed wiring board of Claim 16.   A printed wiring board using the copper clad laminate according to claim 17.   An electronic device using the copper-clad laminate according to claim 17.   A method of manufacturing a printed wiring board in which two or more printed wiring boards are connected by connecting two or more printed wiring boards according to claim 16.   Connecting at least one printed wiring board according to claim 16 and another printed wiring board according to claim 16 or a printed wiring board not corresponding to the printed wiring board according to claim 16; A method of manufacturing a printed wiring board in which two or more printed wiring boards are connected.   An electronic apparatus using one or more printed wiring boards to which at least one printed wiring board according to claim 21 is connected.