Surface-treated copper foil, copper-clad laminate, and printed wiring board

Abstract

Provided is a surface-treated copper foil which comprises a copper foil and a surface treatment layer that is provided on at least one surface of the copper foil. The surface treatment layer contains Cr and one or more elements selected from among Ni, W, Co, Fe, and Mo. When the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Cr to the total atomic ratio of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 30.0% or more. When the surface treatment layer is measured by XPS depth analysis, the ratio of the intensity of Zn to the intensity of Cr is 150% or less at the peak position of Cr closest to the surface of the surface treatment layer, and the maximum value of the intensity of an element which satisfies the conditions (A) and (B) described below is found at a position that is separated from the peak position of Cr closest to the surface of the surface treatment layer by 0.9 nm or more in terms of SiO2.　(A) The maximum value of the intensity of one or more elements selected from among Ni, W, Co, Fe, and Mo is present.　(B) The ratio of the maximum value of the intensity of the element to the intensity of Cr at the peak position of Cr closest to the surface of the surface treatment layer is 35.0% or more.

Description

Surface-treated copper foil, copper-clad laminates, and printed circuit boards

[0001] This disclosure relates to surface-treated copper foil, copper-clad laminates, and printed circuit boards, and more particularly to surface-treated copper foil, copper-clad laminates, and printed circuit boards used in the formation of circuits requiring high-frequency characteristics.

[0002] Copper-clad laminates consist of copper foil and a resin layer on the surface of the copper foil, and are widely used in various applications such as flexible printed circuit boards. Flexible printed circuit boards are manufactured by chemically etching the copper foil of a copper-clad laminate to form circuits (also called "wiring patterns"), and then soldering electronic components onto these circuits.

[0003] As a copper foil provided in a copper-clad laminate, a surface-treated copper foil is known in which a roughening treatment layer is provided on the surface of the copper foil (for example, Patent Document 1). When this surface-treated copper foil is heat-pressed and bonded to a resin substrate which will become the resin layer, the molten resin flows around the roughened particles on the surface of the surface-treated copper foil, thereby firmly maintaining the interface between the copper foil surface and the resin layer (anchor effect). This suppresses the delamination of the circuit from the resin layer.

[0004] In recent years, with the increasing speed and capacity of communications in electronic devices such as personal computers and mobile terminals, electrical signals have become more high-frequency, creating a demand for flexible printed circuit boards capable of handling these frequencies. In particular, as the frequency of an electrical signal increases, signal power loss (attenuation) becomes greater, making data difficult to read. Therefore, reducing signal power loss is essential.

[0005] The causes of signal power loss (transmission loss) in electronic circuits can be broadly divided into two categories. The first is conductor loss, i.e., loss due to the copper foil. The second is dielectric loss, i.e., loss due to the resin layer. In the high-frequency range, current has the characteristic of flowing along the surface of the conductor (i.e., the skin effect). Therefore, if the surface of the copper foil is rough, the current will flow along a complex path. Consequently, from the viewpoint of reducing conductor loss of high-frequency signals, forming a roughened layer on the surface of the copper foil is disadvantageous. On the other hand, regarding the resin layer, by using low-dielectric materials such as PFA (materials with a relative permittivity of less than 2.5 and a dielectric loss tangent of less than 0.001), transmission loss when high-frequency (especially above 5 GHz) AC current flows through the circuit can be suppressed.

[0006] Japanese Patent Publication No. 2012-112009

[0007] As described above, in conventional technology, the adhesion between the copper foil and the resin layer depends on a roughened layer applied to the surface of the copper foil, but the formation of a roughened layer is disadvantageous for reducing conductor loss of high-frequency signals. Against this backdrop, there has been a desire for the development of a technology that can improve adhesion with the resin layer without relying on a roughened layer.

[0008] The embodiments of the present invention have been made to solve the above-mentioned problems, and aim to provide surface-treated copper foil, copper-clad laminates, and printed circuit boards that exhibit excellent adhesion to resin layers.

[0009] The inventors of the present invention conducted intensive research on surface-treated copper foil in order to solve the above problems. As a result, they discovered that adhesion to the resin layer is improved when a surface treatment layer provided on at least one side of the copper foil contains a predetermined element and satisfies predetermined conditions in XPS measurement of the surface of the surface treatment layer and XPS depth analysis of the surface treatment layer, thereby completing the embodiments of the present invention.

[0010] In other words, embodiments of the present invention relate to a surface-treated copper foil comprising a copper foil and a surface treatment layer provided on at least one surface of the copper foil, wherein the surface treatment layer contains Cr and one or more elements selected from Ni, W, Co, Fe, and Mo, and when the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Cr to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 30.0% or more, and when the surface treatment layer is measured by XPS depth analysis, the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface treatment layer is 150% or less, and the maximum intensity of an element satisfying the following conditions (A) and (B) is located at a position 0.9 nm or more away from the Cr peak position closest to the surface of the surface treatment layer in terms of SiO2. (A) There is a maximum intensity of one or more elements selected from Ni, W, Co, Fe, and Mo. (B) The ratio of the maximum intensity of the element to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more.

[0011] Furthermore, embodiments of the present invention relate to a copper-clad laminate comprising the surface-treated copper foil and a resin layer provided on the surface-treated layer of the surface-treated copper foil.

[0012] Furthermore, embodiments of the present invention relate to a printed circuit board comprising the copper-clad laminate, wherein the surface-treated copper foil of the copper-clad laminate has a wiring pattern shape.

[0013] According to embodiments of the present invention, it is possible to provide surface-treated copper foil, copper-clad laminates, and printed circuit boards that exhibit excellent adhesion to resin layers.

[0014] This graph shows the results of the XPS depth analysis for Example 40. This graph shows the relationship between the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and Fe in the surface treatment layer of the surface-treated copper foils of Examples 17 to 24 [Ni / (Ni+Fe)] and the peel strength. This graph shows the relationship between the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and W in the surface treatment layer of the surface-treated copper foils of Examples 28 to 34 [Ni / (Ni+W)] and the peel strength. This graph shows the relationship between the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo in the surface treatment layer of the surface-treated copper foils of Examples 1 to 42 and Comparative Examples 1 to 3 [Fe / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] and the peel strength. This graph shows the relationship between the ratio of the atomic ratio of W to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo in the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3 [W / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] and the peel strength. This graph shows the relationship between the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo in the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3 [Ni / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] and the peel strength. This graph shows the relationship between the ratio of the atomic ratio of Zn to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo in the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3 [Zn / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] and the peel strength.

[0015] Preferred embodiments of the present invention will be described below, but the present invention should not be construed as being limited thereto, and various modifications and improvements can be made based on the knowledge of those skilled in the art, without departing from the spirit of the invention. The multiple components disclosed in the following embodiments can be combined in appropriate ways to form various inventions. For example, some components may be removed from all the components shown in the following embodiments, or components from different embodiments may be combined in appropriate ways.

[0016] In this specification, a numerical range expressed using "~" means a range that includes the numbers before and after "~" as the lower and upper limits, unless otherwise specified. In this specification, a numerical range that includes "greater than" or "less than" means a range that does not include the number as the lower or upper limit. Furthermore, in numerical ranges described in steps in this specification, the upper limit of one step may be replaced with the upper limit of another step described numerical range or the value shown in the example. Furthermore, in numerical ranges described in steps in this specification, the lower limit of one step may be replaced with the lower limit of another step described numerical range or the value shown in the example.

[0017] The surface-treated copper foil according to an embodiment of the present invention comprises a copper foil and a surface treatment layer provided on at least one surface of the copper foil. The surface treatment layer may be provided on only one surface of the copper foil, or on both surfaces of the copper foil. When the surface treatment layer is provided on both surfaces of the copper foil, the types of surface treatment layers may be the same or different.

[0018] The surface treatment layer contains Cr and one or more elements selected from Ni, W, Co, Fe, and Mo. By using a surface treatment layer containing such elements, adhesion to the resin layer may be improved when a resin layer is provided on the surface treatment layer. The surface treatment layer may optionally contain other elements (e.g., Zn, P, S, N, and other impurity elements). Hereinafter, in this specification, "containing a predetermined element" means that the predetermined element is detected when the surface of the surface treatment layer is measured by XPS (i.e., the atomic ratio of the predetermined element is above the detection limit).

[0019] When the surface of the surface treatment layer is measured by XPS (X-ray photoelectron spectroscopy), the ratio of the atomic ratio of Cr to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (hereinafter sometimes abbreviated as "Cr / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is 30.0% or more, preferably 35.0% or more, and more preferably 40.0% or more. By controlling Cr / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) within this range, the adhesion to the resin layer can be improved when a resin layer is provided on the surface treatment layer. As a general trend, it has been found that when the Zn content in the surface treatment layer is high, the adhesion to the resin layer decreases. Therefore, by increasing the Cr / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) ratio as described above, the effect of Zn in inhibiting adhesion can be relatively reduced, and the adhesion to the resin layer is expected to improve. The upper limit of Cr / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited and can be, for example, 95.0% or 90.0%.

[0020] Herein, the atomic ratio of each element is obtained by measuring the surface of the surface-treated layer using XPS. The XPS measurement shall be performed under the following conditions. If the instrument operation software or data analysis software is updated, the software shall be operated and set to be equivalent to the conditions described herein. Instrument: PHI 5000 VersaProbe II manufactured by ULVAC, Inc. Ultimate vacuum: 8.2 × 10⁻⁶ -8Pa Excitation source: Monochromatic AlKα Output: 25.0W Beam diameter: 100 μmφ Incident angle: 90 degrees Extraction angle: 45 degrees Neutralization gun: None In addition, the following orbitals are used in the calculations for XPS measurements. That is, the elements to be measured by XPS are C, N, O, Si, P, S, Cr, Fe, Co, Ni, Cu, Zn, Mo, and W. C: 1s (284.7 eV) N: 1s (400 eV) O: 1s (531 eV) Si: 2s (151 eV) P: Sum of P2p's 2p3 / 2 (130 eV) and 2p1 / 2 (131 eV) S: Sum of S2p's 2p3 / 2 (167 eV) and 2p1 / 2 (168 eV) Cr: 3p (44 eV) Fe: 3p (54 eV) Co: 3p (61 eV) Ni: 2p3 / 2 (854 eV) Cu: 2p3 / 2 (932 eV) Zn: 2p3 / 2 (1022 eV) Mo: Sum of Mo3d's 3d5 / 2 (231 eV) and 3d3 / 2 (235 eV) W: 4d5 / 2 (244 eV) Furthermore, in calculating the peak area of ​​each element, the peak area with the bond energy closest to the above bond energy is calculated after removing the background using the Shirley method. Also, for P, S, and Mo, since it is difficult to separate the two peaks mentioned above, the sum of the peak areas of both peaks is calculated. In addition, for XPS measurements, for each element, the spectrum is acquired in a range of 6 eV before and after the above bond energy (for example, 400 eV ± 6 eV for N) under the narrow scan conditions shown below. Pass energy: 117.4 eV (common to all elements) Step energy: 0.5 eV (common to all elements) Number of integrations: 100 (common to all elements) Note that for P, S, Cr, Fe, Co, and Mo, the spectrum is acquired in the following range instead of the range of 6 eV before and after. P: 124 eV to 137 eV S: 161 eV to 174 eV Cr: 38 eV to 49 eV Fe: 49 eV to 58 eV Co: 58 eV to 63 eV Mo: 225 eV to 237 eV The quantitative value is calculated from the calculated peak area using the relative sensitivity coefficient method. The sensitivity coefficient for each element is the value recommended by the instrument manufacturer. No corrections such as matrix correction are performed during the calculation. The surface of the object to be measured is not decontaminated before performing the XPS measurement.Decontamination refers to removing material from the surface of an object being measured, for example, by sputtering.

[0021] As mentioned above, as a general trend, a higher Zn content in the surface treatment layer reduces adhesion to the resin layer. Therefore, when measured by XPS depth analysis, the ratio of Zn intensity to Cr intensity (hereinafter sometimes abbreviated as "Zn / Cr") at the Cr peak position closest to the surface of the surface treatment layer is 150% or less, preferably 100.0% or less, more preferably 50.0% or less, and even more preferably 10.0% or less. By controlling Zn / Cr within this range, adhesion to the resin layer is improved when a resin layer is provided on the surface treatment layer. The lower limit of Zn / Cr is not particularly limited and may be 0% (Zn may not be included), but for example, it can be 1.0% or 2.0%.

[0022] Here, the XPS depth analysis of the surface treatment layer will be performed under the following sputtering conditions. Other conditions will be the same as those for the XPS measurement described above. <Sputtering Conditions> Ion species: Ar + Acceleration voltage: 3kV; Sweep area: 3mm x 3mm; Sputtering rate: 1.9nm / min (SiO2 equivalent)

[0023] When measured by XPS depth analysis, the surface treatment layer has the maximum intensity of an element satisfying the following conditions (A) and (B) at a position at least 0.9 nm away in terms of SiO2 from the Cr peak position closest to the surface of the surface treatment layer: (A) The maximum intensity of one or more elements, preferably two or more, selected from Ni, W, Co, Fe, and Mo exists. (B) The ratio of the maximum intensity of the said element to the intensity of Cr at the Cr peak position closest to the surface of the surface treatment layer is 35.0% or more, preferably 40.0% or more, and more preferably 50.0% or more. By satisfying the above conditions, adhesion to the resin layer may be improved when a resin layer is provided on the surface treatment layer. The inventors believe that by satisfying these conditions (hereinafter sometimes abbreviated as "underlayment conditions"), the surface state of the chromate layer described later changes, and adhesion to the resin layer is improved. Furthermore, by satisfying the underlayment conditions, the properties of the copper-clad laminate may be improved when a resin layer is provided on the surface treatment layer. The properties of copper-clad laminates include heat resistance, acid resistance, weather resistance, and stain resistance, which will be described later. More specifically, if one or more of the elements Ni, W, Co, and Fe are included in the elements that satisfy the conditions of the substrate, the weather resistance of the copper-clad laminate may be improved. Also, if Mo is included in the elements that satisfy the conditions of the substrate, the stain resistance of the copper-clad laminate may be improved. Here, if the intensity of Cr is at its maximum value at a depth of 0 nm, the depth of 0 nm is defined as the peak position of Cr closest to the surface of the surface-treated layer. The upper limit of the ratio of the maximum intensity of the element to the intensity of Cr at the peak position of Cr closest to the surface of the surface-treated layer is not particularly limited, but can be, for example, 900.0%, 700.0%, or 500.0%.

[0024] The elements that satisfy the conditions of the substrate preferably include one or more selected from Ni, W, and Fe. In the surface treatment layer, the higher the content of Ni, W, and Fe, the more the adhesion to the resin layer tends to improve when a resin layer is provided on the surface treatment layer. Therefore, by including one or more selected from Ni, W, and Fe in the elements that satisfy the conditions of the substrate, the adhesion to the resin layer can be stably improved when a resin layer is provided on the surface treatment layer.

[0025] If the elements that satisfy the conditions of the underlying layer include Fe, the surface treatment layer has an Fe deposition amount of 40 μg / dm 2 The above configuration is preferable. With this configuration, when a resin layer is provided on the surface treatment layer, the adhesion between the resin layer and the surface treatment layer can be stably improved.

[0026] If Ni is included in the elements that satisfy the conditions of the underlying layer, the surface treatment layer will have a Ni adhesion amount of 50 μg / dm 2 The above configuration is preferable. With this configuration, when a resin layer is provided on the surface treatment layer, the adhesion to the resin layer is stably improved, and one or more properties of heat resistance, acid resistance, weather resistance, and penetration resistance can be improved.

[0027] In the embodiment of the present invention, the surface-treated copper foil preferably has a Cr deposition amount of 5 to 100 μg / dm² in the surface treatment layer. 2 More preferably 5 to 50 μg / dm 2 This configuration allows for stable and improved adhesion between the resin layer and the surface treatment layer when a resin layer is provided on top of the surface treatment layer.

[0028] In this specification, the amount of each metal deposited in the surface treatment layer is measured as follows: First, a 0.1 dm × 0.2 dm sample is cut from the surface-treated copper foil, the surface treatment layer is dissolved in a nitric acid solution, and the concentration of each metal in the sample solution is quantified using an ICP emission spectrometer to determine the amount of each metal deposited per unit area (μg / dm²). 2The following conditions are used to calculate the ICP emission spectrometer. Specifically, a Hitachi High-Tech PS3520UVDD2 (AN-063 ICP3520UV-DD2) is used as the ICP emission spectrometer, and the following conditions are met. Note that if the instrument operation software or data analysis software is updated, the software should be operated and set to be equivalent to the conditions described in this specification. Wavelength: 238.277 nm (for Fe), 231.675 nm (for Ni), 267.795 nm (for Cr) Integration time: 1.0 second Number of integrations: 3 Quantitative method: Calibration curve method Blank subtraction: None Output: 1.2 kW Pre-exposure time: 30 seconds Washing time: 20 seconds In addition, the standard solutions used when measuring by ICP-OES are prepared with concentrations of 0, 0.5, and 1.0 μg / mL for each metal to form a calibration curve, and the concentration in the sample is adjusted to be within this range. Furthermore, to prevent contamination from the metal on the opposite side of the surface to be measured (the surface with the surface treatment layer), the opposite side is masked before the analysis is performed.

[0029] Preferably, when measured by XPS depth analysis, the surface treatment layer has a maximum intensity value for Ni and Co, Ni and Fe, Ni and W, or Fe and W located at a position at least 0.9 nm away from the Cr peak closest to the surface of the surface treatment layer (in terms of SiO2 equivalent), and the ratio of the maximum intensity value for Ni and Co, Ni and Fe, Ni and W, or Fe and W to the intensity of Cr at the Cr peak closest to the surface of the surface treatment layer (hereinafter sometimes abbreviated as "ratio of the maximum intensity value of a predetermined element") is 35.0% or more. By satisfying this condition, when a resin layer is provided on the surface treatment layer, adhesion to the resin layer can be improved, and one or more of the properties of heat resistance, acid resistance, weather resistance, and penetration resistance can also be improved. From the viewpoint of stably ensuring the above effects, the ratio of the maximum intensity value of a predetermined element is preferably 40.0% or more, more preferably 50.0% or more. The upper limit of the percentage of the maximum intensity of a given element is not particularly limited, but for example, it can be 900.0%, 700.0%, or 500.0%.

[0030] In one preferred embodiment of the present invention, when the surface-treated copper foil is measured by XPS depth analysis, the maximum intensities of Ni and Fe are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Ni and Fe to the Cr intensity at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, preferably 40.0% or more, and more preferably 50.0% or more. In this case, when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and Fe (hereinafter sometimes abbreviated as "Ni / (Ni+Fe)") is 11.0 to 36.0%, preferably 11.0 to 24.0%. By setting these conditions, the effect of improving adhesion with the resin layer when a resin layer is provided on the surface-treated layer is enhanced.

[0031] In another preferred embodiment of the present invention, when the surface-treated copper foil is measured by XPS depth analysis, the maximum intensities of Fe and W are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Fe and W to the Cr intensity at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, preferably 40.0% or more, and more preferably 50.0% or more. In this case, when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Fe and W (hereinafter sometimes abbreviated as "Fe / (Fe+W)") is 85.0% or more, preferably 90.0% or more. By setting these conditions, the effect of improving adhesion with the resin layer when a resin layer is provided on the surface-treated layer is enhanced. The upper limit of Fe / (Fe+W) is not particularly limited, but for example, it is 98.0% or 95.0%.

[0032] In another preferred embodiment of the present invention, when the surface-treated copper foil is measured by XPS depth analysis, the maximum intensities of Ni and W are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Ni and W to the Cr intensity at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, preferably 40.0% or more, and more preferably 50.0% or more. In this case, when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and W (hereinafter sometimes abbreviated as "Ni / (Ni+W)") is 50.0 to 69.0%, preferably 55.0 to 69.0%. By setting these conditions, the effect of improving adhesion with the resin layer is enhanced when a resin layer is provided on the surface-treated layer.

[0033] In another preferred embodiment, when the surface-treated copper foil according to the present invention is measured by XPS depth analysis, the maximum value of Fe intensity is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum value of Fe intensity to the Cr intensity at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, preferably 40.0% or more, and more preferably 50.0% or more. In this case, when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (hereinafter sometimes expressed as "Fe / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is 12.0% or more, preferably 15.0% or more, and more preferably 18.0% or more. By setting these conditions, the effect of improving adhesion with the resin layer is enhanced when a resin layer is provided on the surface-treated layer. The upper limit of Fe / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited, but for example, it could be 50.0% or 40.0%.

[0034] In a preferred embodiment, the surface-treated copper foil according to an embodiment of the present invention is characterized in that, when the surface treatment layer is measured by XPS depth analysis, the maximum W intensity exists at a position separated by 0.9 nm or more in terms of SiO₂ from the Cr peak position closest to the surface of the surface treatment layer, and the ratio of the maximum W intensity to the Cr intensity at the Cr peak position closest to the surface of the surface treatment layer is 35.0% or more, preferably 40.0% or more, more preferably 50.0% or more. In this case, when the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of W to the sum of atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe and Mo (hereinafter sometimes expressed as "W / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is 5.0% or more, preferably 7.0% or more, more preferably 10.0% or more. By satisfying such conditions, when a resin layer is provided on the surface treatment layer, the effect of improving the adhesion to the resin layer is enhanced. The upper limit of W / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited, and is, for example, 40.0% or 30.0%.

[0035] In another preferred embodiment, the surface-treated copper foil according to an embodiment of the present invention is characterized in that, when the surface treatment layer is measured by XPS depth analysis, the maximum Ni intensity exists at a position separated by 0.9 nm or more in terms of SiO₂ from the Cr peak position closest to the surface of the surface treatment layer, and the ratio of the maximum Ni intensity to the Cr intensity at the Cr peak position closest to the surface of the surface treatment layer is 35.0% or more, preferably 40.0% or more, more preferably 50.0% or more. In this case, when the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe and Mo (hereinafter sometimes expressed as "Ni / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is 9.0% or more, preferably 10.0% or more, more preferably 11.0% or more. By satisfying such conditions, when a resin layer is provided on the surface treatment layer, the effect of improving the adhesion to the resin layer is enhanced. The upper limit of Ni / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited, and is, for example, 40.0% or 30.0%.

[0036] The surface-treated layer, when its surface is measured by XPS, has a ratio of the atomic ratio of Si to the sum of the atomic ratios of Cr, Zn, P, S, N, and Si (hereinafter sometimes abbreviated as "Si / (Cr+Zn+P+S+N+Si)") which is preferably 7.0% or less, more preferably 5.0% or less, and even more preferably 3.0% or less. In conventional surface-treated copper foils, surface treatment using a silane coupling agent is sometimes performed to improve adhesion to the resin layer, but in this case, Si / (Cr+Zn+P+S+N+Si) exceeds 7.0%. In contrast, the surface-treated copper foil according to the embodiment of the present invention can improve adhesion to the resin layer without performing surface treatment using a silane coupling agent, so that Si / (Cr+Zn+P+S+N+Si) can be within the above range. When the resin layer contains fluororesin, surface treatment using a silane coupling agent tends to actually decrease the adhesion between the surface-treated copper foil and the resin layer. The reason for this is thought to be that fluororesins are extremely stable unless surface modification such as plasma treatment is performed, and therefore do not bond with silane coupling agents. Furthermore, if the resin layer contains a highly heat-resistant resin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and the bonding of the surface-treated copper foil and the resin layer is performed by hot pressing at high temperatures (e.g., 300°C or higher), the silane coupling agent may not contribute to bonding with the resin layer due to deterioration or burning out. Note that the lower limit of Si / (Cr+Zn+P+S+N+Si) is not particularly limited and may be 0% (Si may not be included), but it can be, for example, 0.1%.

[0037] When the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Zn to the total atomic ratio of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (hereinafter sometimes abbreviated as "Zn / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is preferably 60.0% or less, more preferably 55.0% or less, still more preferably 30.0% or less, and particularly preferably 10.0% or less. Controlling Zn / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) within such a range improves the adhesion to the resin layer when the resin layer is provided on the surface treatment layer. The lower limit of Zn / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited, and may be 0% (Zn may not be contained), for example, it may be 0.1%.

[0038] When the surface of the surface treatment layer is measured by XPS, the ratio of the total atomic ratio of P, S, and N to the total atomic ratio of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (hereinafter sometimes abbreviated as "(P+S+N) / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is preferably 15.0% or less, more preferably 13.0% or less, and still more preferably 10.0% or less. Controlling (P+S+N) / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) within such a range improves the adhesion to the resin layer when the resin layer is provided on the surface treatment layer. The lower limit of (P+S+N) / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited, and may be 0% (P, S, and N may not be contained), for example, it may be 0.1%.

[0039] When the surface of the surface treatment layer is measured by XPS, the ratio of the sum of the atomic ratios of Co to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (hereinafter sometimes abbreviated as "Co / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is preferably 50.0% or less, more preferably 48.0% or less. By controlling Co / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) within this range, when a resin layer is provided on the surface treatment layer, adhesion to the resin layer is easily improved, and weather resistance can also be improved. The lower limit of Co / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited and may be 0% (Co may not be included), but for example it can be 0.1%.

[0040] When the surface of the surface treatment layer is measured by XPS, the ratio of the sum of the atomic ratios of Mo to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (hereinafter sometimes abbreviated as "Mo / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)") is preferably 14.0% or less, more preferably 13.0% or less. By controlling Mo / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) within this range, when a resin layer is provided on the surface treatment layer, the adhesion to the resin layer is easily improved, as well as the resistance to penetration can be improved. The lower limit of Mo / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) is not particularly limited and may be 0% (Mo may not be included), but for example it can be 0.1%.

[0041] When measured by XPS depth analysis, the surface treatment layer has a position where the ratio of Cu's strength to the sum of the strengths of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu is initially 95% or more, preferably at a depth of 10.0 to 30.0 nm, more preferably 11.0 to 25.0 nm, and even more preferably 12.0 to 20.0 nm in terms of SiO2. If these conditions are met, the thickness of the surface treatment layer will be within an appropriate range, which can improve adhesion to the resin layer when a resin layer is provided on top of the surface treatment layer.

[0042] When measured by XPS depth analysis, the surface treatment layer has a position where the ratio of the intensity of Cr to the sum of the intensities of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu is initially 10% or less, preferably at a depth of 1.0 to 5.0 nm, more preferably 1.2 to 4.5 nm, and even more preferably 1.5 to 4.0 nm in terms of SiO2. If these conditions are met, the thickness of the chromate layer described later will be within an appropriate range, and the adhesion to the resin layer may be improved when a resin layer is provided on the surface treatment layer.

[0043] The surface treatment layer has a root mean square height Sq (hereinafter sometimes abbreviated as "Sq") of 0.30 μm or less, more preferably 0.25 μm or less, and even more preferably 0.20 μm or less. Here, Sq is a height parameter defined in ISO 25178-2:2012 and represents the variation in the height of the protrusions on the surface of the surface treatment layer. Therefore, a large Sq on the surface of the surface treatment layer means that there is a large variation in the height of the protrusions on the surface of the surface treatment layer. By controlling Sq within the above range, the conductor loss of high-frequency signals due to the skin effect can be reduced. The lower limit of the surface Sq is not particularly limited and may be 0 μm, but for example, it may be 0.01 μm or 0.05 μm.

[0044] The surface height (Sq) of the surface treatment layer is determined by measurement in accordance with ISO 25178-2:2012. Specifically, the Sq measurement is performed under the following conditions: The root mean square height (Sq) of the surface treatment copper foil is measured using a laser microscope (LEXT OLS5100) manufactured by Evident Co., Ltd. The Sq measurement result is the average of the results obtained from measurements at five arbitrary locations. The measurement temperature is set to 23-25°C. The main settings for the laser microscope are as follows. If the device operation software or data analysis software is updated, the software should be operated and set to the same conditions as those described in this specification. Objective lens: MPLAPON 50x LEXT (Magnification: 50x, Numerical aperture: 0.95, Working distance: 0.35 mm, Depth of focus: 0.44 μm, Focusing spot diameter: 0.52 μm) Optical zoom magnification: 1x Scanning mode: 3D accuracy priority + color Image size: 257 μm x 256 μm, 1024 x 1024 pixels Laser intensity: 100 Offset: 0 Confocal level: 0 Beam diameter aperture: Off Brightness uniformity correction: On Optical noise filter: On Cutoff: No filter, no F calculation Filter: Gaussian Auto gain: On Brightness: Auto-adjusted Noise reduction: Yes Tilt correction: Yes

[0045] In the surface-treated copper foil according to the embodiment of the present invention, the surface treatment layer is preferably the surface in contact with the resin. The resin preferably contains fluorine from the viewpoint of reducing dielectric loss, and preferably has a repeating CF2CF2 structure. Examples of such resins include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), fluoroethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and polytetrafluoroethylene (PTFE). These can be used individually or in combination of two or more. The reason why the repeating CF2CF2 structure is advantageous in terms of reducing dielectric loss is as follows. - Because fluorine atoms, which have high electronegativity, strongly attract electrons, it is difficult for the electron cloud of CF2 to be biased (i.e., polarization) due to external factors. - Because the atomic radius of fluorine atoms is small and they are densely arranged as CF2 molecules, there is no molecular movement due to external factors. - The repeating structure of CF2CF2 forms a helical structure, and the dipole moment of CF2 is directed toward the center line of the helical structure, so the dipole moments of the entire molecule cancel each other out and the polarizability is extremely small.

[0046] The type of surface treatment layer in the surface-treated copper foil according to the embodiment of the present invention is not particularly limited as long as it satisfies the above-described characteristics, but it is preferable that the surface treatment layer includes a chromate layer and that the chromate layer is the outermost layer. If the surface treatment layer has a chromate layer as the outermost layer, adhesion to the resin layer is easily improved when a resin layer is provided on the surface treatment layer. In addition, since the chromate layer has a rust-preventive effect, there is no need to apply rust-preventive treatment to the surface of the chromate layer. When such surface-treated copper foil, in which the outermost layer is a chromate layer, is measured by XPS depth analysis, the intensity of Cr at the peak position of Cr closest to the surface of the surface treatment layer tends to be the maximum value of the Cr intensity.

[0047] Furthermore, if the details of the surface treatment layer are clear, it is easy to determine whether the chromate layer is the outermost layer. However, if the details of the surface treatment layer are not clear, such determination may sometimes be difficult. In this case, the criterion for determining whether a chromate layer is the outermost layer is: when the surface treatment layer is measured by XPS depth analysis, if the maximum Cr intensity appears within 3.0 nm in terms of SiO2 conversion from the surface of the surface treatment layer, it can be determined that the chromate layer is the outermost layer of the surface treatment layer. For the XPS depth analysis of the surface treatment layer herein, the sputtering conditions are as follows. Other conditions are the same as the XPS measurement conditions described above. <Sputtering Conditions> Ion species: Ar + Acceleration voltage: 3 kV Sweep area: 3 mm × 3 mm Sputtering rate: 1.9 nm / min (in terms of SiO2 conversion)

[0048] The chromate layer can be formed by electroplating. The conditions therefor may be adjusted according to the electroplating apparatus to be used and are not particularly limited. However, the conditions for forming a chromate layer using a general electroplating apparatus are as follows. Note that the chromate treatment may be performed once or multiple times. Plating solution composition: 1 to 10 g / L of Cr salt (e.g., K2Cr2O7), 0 to 0.25 g / L of Zn salt (e.g., ZnSO4·7H2O) Plating solution pH: 1.5 to 12.0 Plating solution temperature: 25 to 60°C Plating conditions: current density 0.1 to 1.4 A / dm 2 , time 0.8 to 5.0 seconds. Furthermore, the chromate layer can also be formed by immersion. In such case, the copper foil may be immersed in the above plating solution for 0.1 to 60 seconds.

[0049] Furthermore, the chromate layer can also be formed only by immersion in a plating solution. When forming a chromate layer by immersion, the same plating solution as that used for electroplating can be used. The immersion time is not particularly limited, but is typically 0.1 to 60 seconds.

[0050] The surface treatment layer may further include a base layer located between the copper foil and the chromate layer. The base layer preferably contains one or more elements selected from Ni, W, Co, Fe, and Mo. A base layer having such elements can improve heat resistance without hindering adhesion between the copper foil and the chromate layer.

[0051] It is preferable that the base layer is in contact with the copper foil. By bringing the base layer into contact with the copper foil, the above effects can be obtained more reliably.

[0052] The undercoat can be formed by electroplating. The conditions are not particularly limited and can be adjusted according to the electroplating equipment used, but the conditions for forming the undercoat using a general electroplating equipment are as follows. Note that electroplating may be performed once or multiple times. Plating solution composition: 0-150 g / L Ni salt (e.g., NiSO4・6H2O), 0-50 g / L W salt (e.g., Na2WO4・2H2O), 0-150 g / L Co salt (e.g., CoSO4・7H2O), 0-150 g / L Fe salt (e.g., FeSO4・7H2O), 0-30 g / L Mo salt (e.g., Na2MoO4・2H2O), 0-25 g / L Zn salt (e.g., ZnSO4・7H2O), 0-30 g / L complexing agent (e.g., trisodium citrate dihydrate, trisodium ammonium citrate) Plating solution pH: 2.0-6.0 Plating solution temperature: 30-60°C Plating conditions: Current density 0.1-10.0 A / dm 2 , time 0.8 to 5.0 seconds

[0053] The copper foil used in the surface-treated copper foil according to the embodiment of the present invention is not particularly limited and may be either electrolytic copper foil or rolled copper foil. Electrolytic copper foil is generally manufactured by electrolytically elastorating copper from a copper sulfate plating bath onto a titanium or stainless steel drum, and has a flat S-surface (shine surface) formed on the rotating drum side and an M-surface (matte surface) formed on the opposite side of the S-surface. The M-surface of electrolytic copper foil generally has minute irregularities. The S-surface of electrolytic copper foil also has minute irregularities because polishing marks from the rotating drum formed during polishing are transferred to it. The surface treatment layer may be provided on either the S-surface or the M-surface of the electrolytic copper foil. Rolled copper foil has minute irregularities on its surface because oil pits are formed by the rolling oil during rolling.

[0054] While there are no particular limitations on the material of the copper foil, if the copper foil is rolled copper foil, high-purity copper such as tough pitch copper (JIS H3100 alloy number C1100) or oxygen-free copper (JIS H3100 alloy number C1020 or JIS H3510 alloy number C1011), which are commonly used as circuit patterns for printed circuit boards, can be used. In addition, copper alloys such as Sn-containing copper, Ag-containing copper, copper alloys with added Cr, Zr, or Mg, or Corson-type copper alloys with added Ni and Si can also be used. In this specification, "copper foil" is a concept that also includes copper alloy foils.

[0055] The thickness of the copper foil is not particularly limited, but can be, for example, 1 to 1000 μm, 1 to 500 μm, 1 to 300 μm, 3 to 100 μm, 5 to 70 μm, 6 to 35 μm, or 9 to 18 μm.

[0056] In the embodiment of the present invention, a surface-treated copper foil may optionally have a roughening layer between the copper foil and the underlayer. By providing a roughening layer, adhesion to the resin layer can be further improved when a resin layer is provided on the surface-treated layer. However, the surface-treated copper foil according to the embodiment of the present invention can ensure sufficient adhesion to the resin layer even without providing a roughening layer. Furthermore, a surface-treated copper foil without a roughening layer does not generate conductor loss due to roughened areas, making it suitable for manufacturing energy-saving high-frequency circuits.

[0057] In a preferred embodiment, the surface-treated copper foil according to the present invention may have a further surface-treated layer on the side of the copper foil opposite to the side on which the above-mentioned surface-treated layer is provided. The further surface-treated layer preferably contains Zn and Ni, and more preferably contains Cr. The inclusion of Zn and Ni in the further surface-treated layer ensures the weather resistance of the further surface-treated layer. In one preferred embodiment, the further surface-treated layer is a surface that is etched for the purpose of circuit formation.

[0058] A copper-clad laminate according to an embodiment of the present invention comprises the above-mentioned surface-treated copper foil and a resin layer provided on the surface-treated layer of the surface-treated copper foil. This copper-clad laminate can be manufactured by bonding a resin substrate, which will be the resin layer, to the surface-treated layer of the above-mentioned surface-treated copper foil. The resin substrate is not particularly limited and any known in the art can be used. Examples of resin substrates include paper-based phenolic resin, paper-based epoxy resin, synthetic fiber cloth-based epoxy resin, glass cloth / paper composite-based epoxy resin, glass cloth / glass nonwoven fabric composite-based epoxy resin, glass cloth-based epoxy resin, polyester film, polyimide resin, liquid crystal polymer, fluororesin such as PTFE, and polyolefin resin.

[0059] In one preferred embodiment of the present invention, the copper-clad laminate preferably has a resin layer containing fluorine. Since fluorine-containing resins have excellent dielectric properties, it becomes possible to form circuits requiring high-frequency characteristics. Furthermore, it is more preferable that the resin layer contains a resin having a repeating CF2CF2 structure. Such a repeating structure makes it easier to stably obtain the above effects. Examples of such resins include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), fluoroethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), and polytetrafluoroethylene (PTFE). These can be used individually or in combination of two or more.

[0060] The method for bonding the surface-treated copper foil to the resin substrate is not particularly limited and can be carried out in accordance with methods known in the art. For example, the surface-treated copper foil and the resin substrate can be laminated and then heat-pressed together. The copper-clad laminate manufactured in this manner can be used in the manufacture of printed circuit boards. The copper-clad laminate according to the embodiment of the present invention has excellent adhesion to the resin layer because it uses the surface-treated copper foil described above.

[0061] A printed circuit board according to an embodiment of the present invention comprises the above-described copper-clad laminate, wherein the surface-treated copper foil of the copper-clad laminate has a wiring pattern shape. This printed circuit board can be manufactured by chemically etching the surface-treated copper foil of the copper-clad laminate to form a wiring pattern (circuit). The method for forming the wiring pattern is not particularly limited, and known methods such as the subtractive method and the semi-additive method can be used. Among these, the subtractive method is preferred for forming the wiring pattern.

[0062] When manufacturing printed circuit boards by the subtractive method, it is preferable to do so as follows: First, a predetermined resist pattern is formed by applying a resist to the surface of the surface-treated copper foil of a copper-clad laminate, exposing it to light, and developing it. Next, the surface-treated copper foil in areas where the resist pattern is not formed (i.e., unwanted areas) is removed by chemical etching to form a wiring pattern. Finally, the resist pattern on the surface-treated copper foil is removed. The various conditions in this subtractive method are not particularly limited and can be carried out in accordance with conditions known in the art. Since the printed circuit board obtained in this way uses the above-mentioned copper-clad laminate, it has excellent adhesion between the resin layer and the wiring pattern.

[0063] The embodiments of the present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these embodiments.

[0064] (Examples 1-45 and Comparative Examples 1-5) Rolled copper foil with a thickness of 18 μm (manufactured by JX Metals Corporation) was prepared. One side of the copper foil was electrolytically degreased and pickled. Then, on the electrolytically degreased and pickled side, a base layer was sequentially formed using electroplating under the conditions shown in Table 1-1, and a chromate layer was sequentially formed using electroplating or immersion under the conditions shown in Table 1-2 to produce a surface-treated copper foil. The plating solution used to form the chromate layer consisted of K2Cr2O7 as the Cr salt and ZnSO4・7H2O as the Zn salt. The temperature of the plating solution for the base layer was 50°C, and the temperature of the plating solution for the chromate layer was 55°C.

[0065]

[0066]

[0067] (Reference Example 1) A rolled copper foil with a thickness of 18 μm (manufactured by JX Metals Corporation) was subjected to a roughening treatment.

[0068] The surface-treated copper foils obtained in the above examples and comparative examples were evaluated as follows.

[0069] <XPS Analysis of the Surface Treatment Layer> The atomic ratio of each element was measured using XPS on the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3 under the conditions described above. The results are shown in Table 2-1. Based on these measurement results, it was confirmed that the surface treatment layers of Examples 1 to 43 contain Cr and one or more elements selected from Ni, W, Co, Fe, and Mo. Furthermore, based on the obtained atomic ratios of each element, the ratio of the atomic ratio of Cr to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (represented as "Cr ratio" in Table 2-1); the ratio of the atomic ratio of Si to the sum of the atomic ratios of Cr, Zn, P, S, N, and Si (represented as "Si ratio" in Table 2-1); the ratio of the atomic ratio of Zn to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (represented as "Zn ratio" in Table 2-1); the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (represented as "Fe ratio" in Table 2-1); Cr The following were calculated: the ratio of the atomic ratio of W to the sum of the atomic ratios of Zn, P, S, N, Ni, W, Co, Fe, and Mo (represented as "W ratio" in Table 2-1); the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (represented as "Ni ratio" in Table 2-1); the ratio of the sum of the atomic ratios of P, S, and N to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo (represented as "P+S+N ratio" in Table 2-1); and the ratio of the atomic ratio of Me to the atomic ratio of Me+X (represented as "Me / (Me+X)" in Table 2-1, with the types of Me and X shown in Table 2-1). Note that these measurements were not performed for Examples 43-45 and Comparative Examples 4-5. However, since the plating conditions for the surface treatment layer in Examples 43 to 45 are almost the same as those in Example 29, there is a high probability that the results for the various items shown in Table 2-1 will be almost the same as those for Example 29. Similarly, since the plating conditions for the surface treatment layer in Comparative Examples 4 to 5 are the same as those for Comparative Example 2, there is a high probability that the results for the various items shown in Table 2-1 will be almost the same as those for Comparative Example 2. These trends are also considered to be the same for the various items in Table 2-3, excluding the peel strength, which will be discussed later.Note that in the examples where the "Si ratio" in Table 2-1 is "≤7.0%", Si is not included as the element measured by XPS. These examples use C, N, O, P, S, Cr, Fe, Co, Ni, Cu, Zn, Mo, and W as the elements measured, and there is no data on the atomic ratio of Si. However, these examples, like Example 4 which uses Si as the element measured, have not undergone silane coupling treatment, and therefore, there is a high probability that the Si ratio will be 7% or less (or even 5% or less), similar to Example 4. Note that Examples 25 and 32 also have not undergone silane coupling treatment, but Si exceeding the detection limit was detected due to contamination.

[0070] <XPS Depth Analysis of Surface Treatment Layers> XPS depth analysis was performed on the surface treatment layers of the surface-treated copper foils in Examples 39-43 and Comparative Example 1 under the conditions described above. The results are shown in Table 2-2. Note that all values ​​in nanometers in Table 2-2 are in terms of SiO2 equivalent. In the XPS depth analysis, the following values ​​were determined: the Cr peak position closest to the surface of the surface treatment layer (represented as "Cr peak position" in Table 2-2); the ratio of the intensity of Zn to the intensity of Cr at that position (represented as "Zn / Cr at Cr peak position" in Table 2-2); the distance from that position to the maximum intensity of each element (Ni, W, Fe, Co, and Mo); and the ratio of the maximum intensity of each element to the intensity of Cr at the Cr peak position closest to the surface of the surface treatment layer (represented as "Zn / Cr at Cr peak position" in Table 2-2). The positions were calculated as follows: the position where the ratio of Cu's intensity to the sum of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu's intensities first exceeds 95% (represented in Table 2-2 as "the position where Cu's intensity first exceeds 95%"); and the position where the ratio of Cr's intensity to the sum of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu's intensities first falls below 10% (represented in Table 2-2 as "the position where Cr's intensity first falls below 10%"). Fe, Co, and Mo were not included in the plating conditions of Examples 39 to 43 and Comparative Example 1. However, as shown in Table 2-2, these elements, such as Fe, were detected due to contamination, exceeding the detection limit. However, for these elements such as Fe included due to contamination, the "ratio of the maximum intensity of each element to the intensity of Cr [%]" in Table 2-2 is all less than 35%. Furthermore, regarding the "distance [nm] from the peak position of Cr to the maximum intensity of each element" in Table 2-2, while Ni and W are both 8.0 nm or less, there are occasional cases where elements included due to contamination exceed 8.0 nm.

[0071] Here, for reference, Figure 1 shows a graph representing the results of the XPS depth analysis of Example 40. As an example, Figure 1 shows the Cr peak position closest to the surface of the surface treatment layer (represented as "Cr peak"), the maximum value of Ni intensity (represented as "Maximum Ni peak value"), and the distance from the Cr peak position to the maximum Ni intensity (represented as "Distance to Maximum Ni peak value"). Note that XPS depth analysis was not performed on the surface treatment layers of Examples 1 to 38 and Examples 44 to 45. However, Examples 1 to 38 and Examples 44 to 45 have the same Cr salt concentration and Zn salt concentration in the chromate layer plating conditions as Example 43. Therefore, it is highly probable that the "Cr peak position [nm]", "Zn / Cr [%] at the Cr peak position", and "position where the Cr intensity first falls below 10% [nm]" shown in Table 2-2 will be similar to those of Example 43. Furthermore, although Examples 1 to 38 and Examples 44 to 45 include cases with different underlayer compositions, elements such as current density, energizing time, and number of energizing cycles in the underlayer plating conditions are the same as or similar to those in Example 43. Therefore, it is highly probable that the "position [nm] where the Cu intensity first reaches 95% or more" in these examples will be similar to that of Example 43. Also, in Example 39, which has the strongest degree of contamination, the "ratio [%) of the maximum Co intensity to the Cr intensity" is 31.6%. Therefore, in these examples, it is highly probable that the "ratio [%) of the maximum intensity of each element to the Cr intensity" in Table 2-2 for elements contained in the underlayer plating solution (i.e., elements that are not contamination) will be 35% or more. In addition, it is considered that the "distance [nm] from the Cr peak position to the maximum intensity of each element" in Table 2-2 will be the same as that of Examples 39 to 43, regardless of the underlayer composition. Therefore, in these examples, there is a high probability that the "distance [nm] from the peak position of Cr to the maximum intensity of each element" for the elements contained in the plating solution of the underlayer will be between 0.9 and 8.0 nm. From the above, Examples 1 to 38 and Examples 44 to 45 are highly likely to satisfy the above-mentioned conditions for the underlayer.

[0072] <Amount of Fe, Ni, and Cr Adhesion in the Surface Treatment Layer> The amount of Fe, Ni, and Cr adhering to the surface treatment layer of the surface-treated copper foil in several examples and comparative examples was measured according to the conditions described above. The results are shown in Table 2-1. In Table 2-1, NA means that the process was not performed. Note that, except for Examples 25 and 34, the elements marked NA are not contained in the plating solution that forms the surface treatment layer, so even if the amount of adhesion were measured, it would be 0 μg / dm 2 or 0 μg / dm 2 It is highly probable that the value will be close to this. Also, the evaluation results written in parentheses indicate that the results are estimated from other test results. Since the Cr salt concentration in the chromate layer plating solution is the same in all examples and comparative examples, it is considered that the amount of Cr deposited will not vary significantly. Therefore, the amount of Cr deposited in Examples 28-29 and Example 34, as written in parentheses, is 5-100 μg / dm, similar to the other examples. 2 It is highly likely that it will fall within that range.

[0073] <Root Mean Square Height Sq of the Surface Treatment Layer> In Examples 1-42, Comparative Examples 1-3, and Reference Example 1, the root mean square height Sq of the surface treatment layer was measured according to the conditions described above for the surface-treated copper foils. The results are shown in Table 2-3. Note that in Examples where "Sq [μm]" in Table 2-3 is "≦0.20", the root mean square height Sq was not measured. However, as shown in Table 2-3, regardless of the plating conditions of the surface treatment layer (composition of the underlayer, composition of the chromate layer), the root mean square height Sq is 0.16 to 0.18 μm, so even in Examples where "≦0.20", there is a high probability that Sq will be 0.2 μm or less, similar to the other Examples. Note that in Oita's Examples, the current density in the underlayer and chromate layer plating conditions was 1.4 A / dm 2 In Examples 23-24 and 33, the current density under plating conditions for the undercoat or chromate layer was 0.5 A / dm². 2 However, since Sq tends to decrease as the current density decreases, it is highly probable that Sq will be 0.2 μm or less in these examples as well.

[0074] <Preparation of Copper-Clad Laminates> Using PFA (Neoflon® AF-0050, manufactured by Daikin Corporation, with a thickness of 50 μm) as the resin substrate, surface-treated copper foil obtained in Examples 1 to 42, Comparative Examples 1 to 3, and Reference Example 1, PFA, and surface-treated copper foil manufactured by JX Metals Corporation were laminated in that order, and a vacuum heat press was performed to produce copper-clad laminates. At this time, the chromate layer side of the surface-treated copper foil obtained in the above examples and comparative examples, and the roughened surface side of the surface-treated copper foil manufactured by JX Metals Corporation were positioned to face the PFA. The vacuum heat press was performed under the following conditions: temperature 310°C, pressure 0.1 MPa, press time 10 minutes, and cooling time approximately 2 hours. Furthermore, in Example 44 and Comparative Example 4, the resin substrate was changed to FEP (Neoflon® FEP manufactured by Daikin Corporation, 50 μm thick), and in Example 45 and Comparative Example 5, the resin substrate was changed to ETFE (a commercially available product manufactured by AS ONE Corporation, 50 μm thick), and copper-clad laminates were manufactured in the same manner as described above.

[0075] <Peel Strength> Surface-treated copper foil obtained in Examples 1-42, 44 and 45, Comparative Examples 1-5, and Reference Example 1 of copper-clad laminates was chemically etched to form 1 mm wide wiring in the MD direction (longitudinal direction of the rolled copper foil). The wiring was formed according to the usual method. The surface-treated copper foil side manufactured by JX Metals Corporation was bonded to a rigid substrate and cut to a predetermined size to serve as a test piece for measurement. Next, the strength (MD90° peel strength) when peeling this test piece (surface-treated copper foil) at a 90° angle to the surface of the resin substrate, i.e., vertically upward relative to the surface of the resin substrate, was measured. The pulling speed was set to 50 mm / min. Measurements were taken five times, and the average value was taken as the result of the peel strength. In some cases, the peel strength was too strong, making measurement difficult with 1 mm wide wiring. In such cases, 0.4 mm wide wiring was formed and the peel strength was measured. The results are shown in Table 2-3.

[0076] <Heat Resistance> In several copper-clad laminates, surface-treated copper foil obtained in the above examples and comparative examples was chemically etched to form 1 mm wide wiring in the MD direction (longitudinal direction of the rolled copper foil). The wiring was floated in a solder bath containing 260°C solder so that the surface-treated copper foil was in contact with the solder, and removed after 20 seconds. The peel strength was then measured using the method described above. The rate of change in peel strength was then calculated using the following formula: Rate of change in peel strength [%] = (Peel strength before solder contact - Peel strength after solder contact) / Peel strength before solder contact × 100 In this evaluation, a rate of change in peel strength of less than 10% is expressed as "○: Excellent heat resistance", a rate of change in peel strength of 10% or more and less than 30% is expressed as "△: Sufficient heat resistance", and a rate of change in peel strength of 30% or more is expressed as "×: Insufficient heat resistance". The results are shown in Table 2-3. In Table 2-3, NA indicates that it was not measured.

[0077] <Acid Resistance> In several copper-clad laminates, the surface-treated copper foil obtained in the above examples and comparative examples was chemically etched to form 75 mm long straight wiring in bundles of 10 strands of 0.2 mm in the MD direction (longitudinal direction of the rolled copper foil). These test pieces were immersed in an aqueous solution containing 18 vol% hydrochloric acid at room temperature for 60 minutes and in an aqueous solution containing 10 wt% sulfuric acid at 40°C for 15 minutes, and then the peel strength was measured according to the method described above. The rate of change in peel strength was then calculated based on the following formula: Rate of change in peel strength [%] = (Peel strength before immersion - Peel strength after immersion) / Peel strength before immersion × 100 A rate of change in peel strength of less than 10% was classified as "○: Excellent acid resistance", a rate of change in peel strength of 10% or more and less than 30% was classified as "△: Sufficient acid resistance", and a rate of change in peel strength of 30% or more was classified as "×: Insufficient acid resistance". The results are shown in Table 2-3. Note that evaluation results indicated in parentheses in the evaluation indicate results that are estimated from other test results. For example, in Examples 18 and 19, where the underlayer plating type is NiFe, the "Me / (Me+X)[%]" in Table 2-1 falls between that of Example 17 and Example 20. Both Example 17 and Example 20 have an acid resistance of "△". Therefore, there is a high probability that the acid resistance of Examples 18 and 19 is also "△".

[0078] <Weather Resistance> Several surface-treated copper foils were placed in an atmospheric heating furnace at 210°C for 10 minutes, and the presence or absence of discoloration was checked. Care was taken to ensure that the surface of the surface-treated copper foil was exposed when placing it in the heating furnace. Surface-treated copper foils that did not discolor were classified as "○: Excellent weather resistance", those that turned purple were classified as "△: Sufficient weather resistance", and those that turned gray were classified as "×: Insufficient weather resistance". The results are shown in Table 2-3. Note that evaluation results written in parentheses indicate that the results are estimated from the results of other tests. For example, in Examples 18 and 19, where the plating type of the underlayer is NiFe, the "Me / (Me+X) [%]" in Table 2-1 is between that of Example 17 and Example 20. The weather resistance of Example 17 is "○", and the weather resistance of Example 20 is "△". Therefore, there is a high probability that the weather resistance of Examples 18 and 19 is "△" or "○".

[0079] <Stain Resistance> In several copper-clad laminates, the surface-treated copper foil obtained in the above examples and comparative examples was chemically etched to form 75 mm long straight wiring in bundles of 10 strands of 0.2 mm each, in the MD direction (longitudinal direction of the rolled copper foil). The wiring of this test piece was immersed for 5 minutes in an aqueous solution of CEP-750 (manufactured by Mitsubishi Gas Chemical Trading Co., Ltd.) diluted 5 times. After that, it was washed with water and immersed for 30 seconds in an aqueous solution containing 2 vol% BTA (benzotriazole). The wiring after immersion was observed under a microscope, and those with an acid penetration width from the edge of less than 1 μm were classified as "○: Excellent stain resistance", those with an acid penetration width from the edge of 1 μm or more but less than 10 μm were classified as "△: Sufficient stain resistance", and those with an acid penetration width from the edge of 10 μm or more were classified as "×: Insufficient stain resistance". The results are shown in Table 2-3. Note that evaluation results indicated in parentheses are results estimated from other test results. For example, in Examples 18 and 19, where the undercoat plating type is NiFe, the "Me / (Me+X)[%]" in Table 2-1 falls between that of Example 17 and Example 20. Both Example 17 and Example 20 have a stain resistance of "○". Therefore, there is a high probability that the stain resistance of Examples 18 and 19 is also "○".

[0080]

[0081]

[0082]

[0083] As shown in Tables 2-1 to 2-3, when comparing surface-treated copper foils in Examples 1 to 42, 44, and 45 with identical resin substrates, it was found that they had higher peel strength and superior adhesion to the resin layer compared to the surface-treated copper foils in Comparative Examples 1 to 5.

[0084] As shown in Table 2-3, it can be seen that when the elements satisfying the above-mentioned substrate conditions include one or more elements selected from Ni, W, Co, Fe, and Mo, one or more of the properties of heat resistance, acid resistance, weather resistance, and penetration resistance are improved. Heat resistance is "○" in all examples regardless of the type of substrate. Therefore, it is considered that heat resistance is improved when the elements satisfying the substrate conditions include one or more elements selected from Ni, W, Co, Fe, and Mo. Acid resistance in Examples 13-25 and 28-33, which contain Ni as a substrate type, is "△" to "○". Therefore, it is considered that acid resistance is improved when Ni is included in the elements satisfying the substrate conditions. Weather resistance is "△" to "○" in Examples 1-3, 6-8, 11-25, 28-33, and 35-42, which do not contain Mo as a substrate type. Therefore, it is considered that weather resistance improves when the elements satisfying the conditions of the substrate include one or more elements selected from Ni, W, Co, and Fe. In Example 1, where the substrate is Co only, the stain resistance is "×", whereas in Examples 4 and 5, where the substrate is CoMo, it is "△" or "〇". Therefore, it is considered that stain resistance improves when Mo is included in the elements satisfying the conditions of the substrate.

[0085] As shown in Tables 2-2 and 2-3, Examples 39 to 43, where the "Zn / Cr [%] at the Cr peak position" in Table 2-2 is 150% or less, exhibit higher peel strength compared to Comparative Example 1, where the ratio exceeds 150%. Furthermore, by controlling this ratio to 100% or less, the peel strength can be improved to 0.80 kgf / cm or higher. Additionally, by controlling this ratio to 10% or less, the peel strength can be improved to 0.9 kgf / cm or higher.

[0086] As shown in Table 2-3, when the elements satisfying the conditions of the substrate include Ni and Co, Ni and Fe, Ni and W, or Fe and W, all properties such as heat resistance, acid resistance, weather resistance, and penetration resistance are rated "△" or "〇," indicating high overall substrate properties.

[0087] Referring to Examples 8 (underlying layer type Fe), 11-12 (underlying layer type FeW), and 34 (underlying layer type W) in Tables 2-1 and 2-3, it can be shown that when the elements satisfying the underlying layer conditions include Fe and W, and when the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Fe and W is 85.0% or more, the peel strength can be improved to 1.4 kgf / cm or more.

[0088] As shown in Tables 2-1 and 2-3, the amount of Fe deposited in the surface treatment layer is 40 μg / dm 2 By controlling the process as described above, the peel strength can be increased to 1.1 kgf / cm or higher, except for Example 36 which contains Zn in the base layer.

[0089] As shown in Tables 2-1 and 2-3, the amount of Ni deposited in the surface treatment layer is 50 μg / dm 2 In the above cases, all properties of heat resistance, acid resistance, weather resistance, and penetration resistance are "△" or "○". Therefore, by controlling the amount of Ni attached to the surface treatment layer in this way, heat resistance, acid resistance, weather resistance, and penetration resistance can be improved.

[0090] Here, Figure 2 shows a graph illustrating the relationship between the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and Fe [Ni / (Ni+Fe)] obtained by XPS measurement of the surface treatment layer of the surface-treated copper foil in Examples 17 to 24, and the peel strength. As shown in Figure 2, by controlling Ni / (Ni+Fe) to 11.0 to 36.0%, the peel strength can be improved to 1.50 kgf / cm or higher.

[0091] Figure 3 shows a graph illustrating the relationship between the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and W [Ni / (Ni+W)] obtained by XPS measurement of the surface treatment layer of the surface-treated copper foil in Examples 28 to 34, and the peel strength. As shown in Figure 3, by controlling Ni / (Ni+W) to 50.0-69.0%, the peel strength can be improved to 1.15 kgf / cm or higher.

[0092] Figure 4 shows a graph illustrating the relationship between the ratio of the atomic ratio of Fe [Fe / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo] obtained by XPS measurement of the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3, and the peel strength. As shown in Figure 4, it can be seen that the peel strength tends to increase as Fe / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) increases. Furthermore, by controlling Fe / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) to 12.0% or higher, it tends to be easier to improve the peel strength to 1.40 kgf / cm or higher.

[0093] Figure 5 shows a graph illustrating the relationship between the ratio of the atomic ratio of W to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo [W / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] obtained by XPS measurement of the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3, and the peel strength. As shown in Figure 5, it can be seen that the peel strength tends to increase as W / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) increases. Furthermore, by controlling W / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) to 5.0% or higher, it tends to be easier to improve the peel strength to 0.70 kgf / cm or higher.

[0094] Figure 6 shows a graph illustrating the relationship between the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo [Ni / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] obtained by XPS measurement of the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3, and the peel strength. As shown in Figure 6, it can be seen that the peel strength tends to increase as Ni / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) increases. Furthermore, by controlling Ni / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) to 10.0% or higher, the peel strength can be improved to 0.70 kgf / cm or higher.

[0095] Figure 7 shows a graph illustrating the relationship between the ratio of the atomic ratio of Zn [Zn / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo)] to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo] obtained by XPS measurement of the surface treatment layer of the surface-treated copper foil in Examples 1 to 42 and Comparative Examples 1 to 3, and the peel strength. As shown in Figure 7, by controlling Zn / (Cr+Zn+P+S+N+Ni+W+Co+Fe+Mo) to 60.0% or less, the peel strength can be improved to 0.40 kgf / cm or more. Furthermore, by controlling this ratio to 50.0% or less, the peel strength can be improved to 0.60 kgf / cm or more. Furthermore, by controlling this ratio to 40.0% or less, the peel strength can be improved to 0.70 kgf / cm or more.

[0096] As can be seen from the above results, according to the embodiments of the present invention, it is possible to provide surface-treated copper foil, copper-clad laminates, and printed circuit boards that have excellent adhesion to resin layers.

[0097] Therefore, embodiments of the present invention can be as follows.

[0098] [1] A surface-treated copper foil comprising a copper foil and a surface treatment layer provided on at least one surface of the copper foil, wherein the surface treatment layer contains Cr and one or more elements selected from Ni, W, Co, Fe, and Mo, and when the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Cr to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 30.0% or more, and when the surface treatment layer is measured by XPS depth analysis, the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface treatment layer is 150% or less, and the maximum intensity of an element satisfying the following conditions (A) and (B) is located at a position 0.9 nm or more away in SiO2 terms from the Cr peak position closest to the surface of the surface treatment layer. (A) There is a maximum intensity of one or more elements selected from Ni, W, Co, Fe, and Mo. (B) The ratio of the maximum intensity of the element to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more.

[0099] [2] The surface-treated copper foil according to [1], wherein when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Si to the sum of the atomic ratios of Cr, Zn, P, S, N, and Si is 7.0% or less.

[0100] [3] The surface-treated copper foil according to [1] or [2], wherein the root mean square height Sq of the surface of the surface-treated layer is 0.30 μm or less.

[0101] [4] The surface-treated copper foil according to any one of [1] to [3], wherein when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Zn to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 60.0% or less.

[0102] [5] The surface-treated copper foil according to any one of [1] to [4], wherein the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 100.0% or less.

[0103] [6] The surface-treated copper foil according to any one of [1] to [4], wherein the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 10.0% or less.

[0104] [7] A surface-treated copper foil according to any one of [1] to [6], having the maximum intensity of two or more elements satisfying conditions (A) and (B) at a position at a distance of 0.9 nm or more in terms of SiO2 from the Cr peak position closest to the surface of the surface-treated layer.

[0105] [8] The surface-treated copper foil according to any one of [1] to [7], wherein the maximum intensity of Ni and Co, Ni and Fe, Ni and W, or Fe and W exists at a position at a distance of 0.9 nm or more in terms of SiO2 from the Cr peak position closest to the surface of the surface-treated layer, and the ratio of the maximum intensity of Ni and Co, Ni and Fe, Ni and W, or Fe and W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more.

[0106] [9] The surface-treated copper foil according to [8], wherein the maximum intensities of Ni and Fe are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Ni and Fe to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and Fe is 11.0 to 36.0%.

[0107]

[10] The surface-treated copper foil according to [8], wherein the maximum values ​​of the intensities of Fe and W are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum values ​​of the intensities of Fe and W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Fe and W is 85.0% or more.

[0108]

[11] The surface-treated copper foil according to [8], wherein the maximum intensities of Ni and W are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Ni and W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and W is 50.0 to 69.0%.

[0109]

[12] A surface-treated copper foil according to any one of [1] to [6], having the maximum intensity of one or more elements selected from Ni, W, and Fe that satisfies conditions (A) and (B) at a position at a distance of 0.9 nm or more in terms of SiO2 from the Cr peak position closest to the surface of the surface-treated layer.

[0110]

[13] The surface-treated copper foil according to

[12] , wherein the maximum value of Fe intensity is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum value of Fe intensity to the Cr intensity at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 12.0% or more.

[0111]

[14] The surface treatment layer has an Fe deposition amount of 40 μg / dm 2 The surface-treated copper foil described above, as in

[12] or

[13] .

[0112]

[15] The surface-treated copper foil according to

[12] , wherein the maximum intensity of W is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensity of W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of W to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 5.0% or more.

[0113]

[16] The surface-treated copper foil according to

[12] , wherein the maximum intensity of Ni is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensity of Ni to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 9.0% or more.

[0114]

[17] The surface treatment layer has a Ni adhesion amount of 50 μg / dm 2 The above describes the surface-treated copper foil described in any one of

[12] to

[16] .

[0115]

[18] The surface-treated copper foil according to any one of [1] to

[17] , wherein when the surface of the surface-treated layer is measured by XPS, the ratio of the sum of the atomic ratios of P, S and N to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe and Mo is 15.0% or less.

[0116]

[19] The surface-treated copper foil according to any one of [1] to

[18] , wherein when the surface-treated layer is measured by XPS depth analysis, the position where the ratio of the strength of Cu to the sum of the strengths of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu first becomes 95% or more is 10.0 to 30.0 nm in terms of SiO2.

[0117]

[20] The surface-treated copper foil according to any one of [1] to

[19] , wherein when the surface-treated layer is measured by XPS depth analysis, the position where the ratio of the intensity of Cr to the sum of the intensities of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu is first 10% or less is 1.0 to 5.0 nm in terms of SiO2.

[0118]

[21] The surface-treated copper foil according to any one of [1] to

[20] , wherein the surface treatment layer includes a chromate layer, and the chromate layer is the outermost layer.

[0119]

[22] The surface-treated copper foil according to

[21] , wherein the surface-treated layer further comprises a base layer located between the copper foil and the chromate layer, and the base layer comprises one or more selected from Ni, W, Co, Fe and Mo.

[0120]

[23] The surface-treated copper foil according to

[22] , wherein the underlayer is in contact with the copper foil.

[0121]

[24] The surface treatment layer has a Cr deposition amount of 5 to 100 μg / dm 2 The surface-treated copper foil described in any one of [1] to

[23] .

[0122]

[25] The surface-treated copper foil further comprises a surface treatment layer on the side of the copper foil opposite to the side on which the surface treatment layer is provided, wherein the further surface treatment layer comprises Zn and Ni, according to any one of [1] to

[24] .

[0123]

[26] The surface-treated copper foil according to

[25] , wherein the further surface-treated layer further comprises Cr.

[0124]

[27] The surface treatment layer is the surface in contact with the resin, the surface treated copper foil according to any one of [1] to

[26] .

[0125]

[28] The surface-treated copper foil according to

[27] , wherein the resin contains fluorine.

[0126]

[29] A copper-clad laminate comprising a surface-treated copper foil according to any one of [1] to

[28] and a resin layer provided on the surface-treated layer of the surface-treated copper foil.

[0127]

[30] The copper-clad laminate according to

[29] , wherein the resin layer comprises a resin containing fluorine.

[0128]

[31] The copper-clad laminate according to

[29] or

[30] , wherein the resin layer comprises a resin having a repeating CF2CF2 structure.

[0129]

[32] A printed circuit board comprising a copper-clad laminate according to any one of

[29] to

[31] , wherein the surface-treated copper foil of the copper-clad laminate has a wiring pattern shape.

[0130] (Potential Contribution to SDGs) According to the above embodiment, it is possible to provide surface-treated copper foil, copper-clad laminates, and printed circuit boards with excellent adhesion to resin layers, which may improve product yield in the manufacture of electronic devices and the like. Improved product yield leads to a stable supply of products and a reduction in the loss of metal raw materials, which are limited resources. Therefore, the above embodiment may contribute to Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," and Goal 12, "Ensure sustainable consumption and production patterns," of the United Nations-led Sustainable Development Goals (SDGs).

Claims

1. A surface-treated copper foil comprising a copper foil and a surface treatment layer provided on at least one surface of the copper foil, wherein the surface treatment layer contains Cr and one or more elements selected from Ni, W, Co, Fe, and Mo, and when the surface of the surface treatment layer is measured by XPS, the ratio of the atomic ratio of Cr to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 30.0% or more, and when the surface treatment layer is measured by XPS depth analysis, the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface treatment layer is 150% or less, and the maximum intensity of an element satisfying the following conditions (A) and (B) is located at a position 0.9 nm or more away in SiO2 terms from the Cr peak position closest to the surface of the surface treatment layer: (A) There is a maximum intensity of one or more elements selected from Ni, W, Co, Fe, and Mo. (B) The ratio of the maximum intensity of the element to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more.

2. The surface-treated copper foil according to claim 1, wherein when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Si to the sum of the atomic ratios of Cr, Zn, P, S, N, and Si is 7.0% or less.

3. The surface-treated copper foil according to claim 1 or 2, wherein the root mean square height Sq of the surface of the surface-treated layer is 0.30 μm or less.

4. The surface-treated copper foil according to claim 1 or 2, wherein when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Zn to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 60.0% or less.

5. The surface-treated copper foil according to claim 1 or 2, wherein the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 100.0% or less.

6. The surface-treated copper foil according to claim 1 or 2, wherein the ratio of the intensity of Zn to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 10.0% or less.

7. The surface-treated copper foil according to claim 1 or 2, wherein the maximum intensity of two or more elements satisfying conditions (A) and (B) is located at a position at a distance of 0.9 nm or more in terms of SiO2 from the Cr peak position closest to the surface of the surface-treated layer.

8. The surface-treated copper foil according to claim 1 or 2, wherein the maximum intensity of Ni and Co, Ni and Fe, Ni and W, or Fe and W exists at a position at a distance of 0.9 nm or more in terms of SiO2 from the Cr peak position closest to the surface of the surface-treated layer, and the ratio of the maximum intensity of Ni and Co, Ni and Fe, Ni and W, or Fe and W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more.

9. The surface-treated copper foil according to claim 8, wherein the maximum intensities of Ni and Fe are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Ni and Fe to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and Fe is 11.0 to 36.0%.

10. The surface-treated copper foil according to claim 8, wherein the maximum intensities of Fe and W are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Fe and W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Fe and W is 85.0% or more.

11. The surface-treated copper foil according to claim 8, wherein the maximum intensities of Ni and W are located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensities of Ni and W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Ni and W is 50.0 to 69.0%.

12. The surface-treated copper foil according to claim 1 or 2, wherein the surface-treated copper foil has the maximum intensity of one or more elements selected from Ni, W, and Fe that satisfy conditions (A) and (B) at a position 0.9 nm or more away in terms of SiO2 from the Cr peak position closest to the surface of the surface-treated layer.

13. The surface-treated copper foil according to claim 12, wherein the maximum value of Fe intensity is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum value of Fe intensity to the Cr intensity at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Fe to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 12.0% or more.

14. The surface treatment layer has an Fe deposition amount of 40 μg / dm 2 The above is the surface-treated copper foil according to claim 12.

15. The surface-treated copper foil according to claim 12, wherein the maximum intensity of W is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensity of W to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of W to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 5.0% or more.

16. The surface-treated copper foil according to claim 12, wherein the maximum intensity of Ni is located at a position at least 0.9 nm away from the Cr peak position closest to the surface of the surface-treated layer in terms of SiO2, and the ratio of the maximum intensity of Ni to the intensity of Cr at the Cr peak position closest to the surface of the surface-treated layer is 35.0% or more, and when the surface of the surface-treated layer is measured by XPS, the ratio of the atomic ratio of Ni to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe, and Mo is 9.0% or more.

17. The surface treatment layer has a Ni adhesion amount of 50 μg / dm 2 The above is the surface-treated copper foil according to claim 12.

18. The surface-treated copper foil according to claim 1 or 2, wherein when the surface of the surface-treated layer is measured by XPS, the ratio of the sum of the atomic ratios of P, S and N to the sum of the atomic ratios of Cr, Zn, P, S, N, Ni, W, Co, Fe and Mo is 15.0% or less.

19. The surface-treated copper foil according to claim 1 or 2, wherein when the surface-treated layer is measured by XPS depth analysis, the position where the ratio of the strength of Cu to the sum of the strengths of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu first reaches 95% or more is 10.0 to 30.0 nm in terms of SiO2.

20. The surface-treated copper foil according to claim 1 or 2, wherein when the surface-treated layer is measured by XPS depth analysis, the position where the ratio of the intensity of Cr to the sum of the intensities of Zn, Cr, Ni, W, Co, Fe, Mo, and Cu is first 10% or less is 1.0 to 5.0 nm in terms of SiO2.

21. The surface-treated copper foil according to claim 1 or 2, wherein the surface treatment layer includes a chromate layer, and the chromate layer is the outermost layer.

22. The surface-treated copper foil according to claim 21, wherein the surface treatment layer further comprises a base layer located between the copper foil and the chromate layer, and the base layer comprises one or more selected from Ni, W, Co, Fe, and Mo.

23. The surface-treated copper foil according to claim 22, wherein the underlayer is in contact with the copper foil.

24. The surface treatment layer has a Cr deposition amount of 5 to 100 μg / dm 2 The surface-treated copper foil according to claim 1 or 2.

25. The surface-treated copper foil according to claim 1 or 2, wherein the surface-treated copper foil comprises a further surface-treated layer on the side of the copper foil opposite to the side on which the surface-treated layer is provided, and the further surface-treated layer comprises Zn and Ni.

26. The surface-treated copper foil according to claim 25, wherein the further surface treatment layer further comprises Cr.

27. The surface-treated copper foil according to claim 1 or 2, wherein the surface-treated layer is the contact surface with the resin.

28. The surface-treated copper foil according to claim 27, wherein the resin contains fluorine.

29. A copper-clad laminate comprising a surface-treated copper foil according to claim 1 or 2, and a resin layer provided on the surface-treated layer of the surface-treated copper foil.

30. The copper-clad laminate according to claim 29, wherein the resin layer comprises a resin containing fluorine.

31. The copper-clad laminate according to claim 29, wherein the resin layer comprises a resin having a repeating CF2CF2 structure.

32. A printed circuit board comprising a copper-clad laminate according to claim 29, wherein the surface-treated copper foil of the copper-clad laminate has a wiring pattern shape.

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