TW202302914A - Roughened copper foil, copper foil with carrier, copper-cladded laminate board, and printed wiring board - Google Patents

Abstract

Provided is a roughened copper foil capable of realizing both excellent transmission properties and high shear strength, in the processing of a copper-clad laminate or the production of a printed wiring board. This roughened copper foil has a roughened surface on at least one side thereof. This roughened surface has a plurality of peaks, which protrude with respect to a reference plane, and a plurality of valleys, which are recessed with respect to the reference plane. When an image of the roughened surface obtained using FIB-SEM was subjected to three-dimensional image analysis, the sum total of the peak and valley heights calculated as the sum of the peak volume and the valley volume in a 2000 nm * 2000 nm analysis area is 1.4 * 108 nm3 to 3.5 * 108 nm3, and the average height of the peaks and valleys calculated as the sum of the average peak height and the average valley height is 40 nm to 90 nm.

Description

Roughened copper foil, copper foil with carrier, copper foil laminate and printed wiring board

The invention relates to a roughened copper foil, a copper foil with a carrier, a copper foil laminate and a printed wiring board.

In recent years, MSAP (Modified Semi-Additive Process, Modified Semi-Additive Process) method has been widely used as a manufacturing method for printed wiring boards suitable for miniaturization of circuits. The MSAP method is a method suitable for forming extremely fine circuits, and it is performed using copper foil with a carrier in order to make full use of its characteristics. For example, as shown in FIGS. 1 and 2 , an ultra-thin copper foil (roughened copper foil 10 ) is pressed through a prepreg 12 and an undercoat layer 13 to make close contact with a lower layer circuit 11b on a base material 11a. On the insulating resin substrate 11 (step (a)), after peeling off the carrier (not shown), via holes 14 are formed by laser drilling if necessary (step (b)). Then, after implementing the electroless copper plating 15 (step (c)), by using the exposure and development of the dry film 16 to mask with a specific pattern (step (d)), the copper electroplating 17 is implemented (step (e) ). After the dry film 16 is removed to form the wiring portion 17a (step (f)), unnecessary ultra-thin copper foil etc. between the wiring portions 17a and 17a adjacent to each other are removed by etching over the entire thickness thereof. (step (g)) to obtain wiring 18 formed in a specific pattern. Here, in order to improve the physical adhesion between the circuit and the substrate, the surface of the ultra-thin copper foil is generally roughened.

Actually, several types of copper foil with a carrier excellent in fine circuit formability by MSAP method etc. are proposed. For example, Patent Document 1 (International Publication No. 2016/117587) discloses a copper foil with a carrier having an ultra-thin copper foil having an average distance between surface peaks of the surface on the release layer side of 20 µm or less, and the maximum height difference between the peeling layer and the surface on the opposite side is 1.0 µm or less. According to this aspect, both fine circuit formability and laser processability can be achieved. In addition, in Patent Document 2 (JP-A-2018-26590), the following copper foil with a carrier is disclosed. For the purpose of improving the formability of fine circuits, the maximum peak height Sp and protrusion of the side surface of the ultra-thin copper layer based on ISO25178 are disclosed. The ratio Sp/Spk of the peak height Spk is 3.271 or more and 10.739 or less.

On the other hand, as the circuit becomes thinner, in the process of mounting the printed wiring board, the circuit is easily peeled off due to the physical stress (that is, shear stress) from the lateral direction applied to the circuit, and the problem of the decline in the yield is obvious. change. Regarding this point, there is shear strength (shear strength) as one of the physical adhesion indicators between the circuit and the substrate. In order to effectively avoid the above-mentioned circuit peeling, a roughened copper foil suitable for improving the shear strength is proposed. . For example, Patent Document 3 (International Publication No. 2020/031721) discloses a roughened copper foil in which the maximum height Sz specified in ISO25178, the expansion area ratio Sdr of the interface, and the peak apex density Spd are respectively controlled within specific ranges. According to such a roughened copper foil, both excellent etching properties and high shear strength can be achieved in the processing of copper foil laminates or in the manufacture of printed wiring boards.

In addition, with the high-performance of mobile electronic devices in recent years, in order to perform high-speed processing of a large amount of information, the frequency of signals is promoted, and in particular, it is suitable for the 5th generation mobile communication system (5G) or the 6th generation. Printed wiring boards for high-frequency applications such as mobile communication systems (6G). In such a high-frequency printed wiring board, reduction of transmission loss is desired in order to transmit a high-frequency signal without lowering the quality. A printed wiring board has copper foil processed into a wiring pattern and an insulating resin base material, and the transmission loss is mainly the conductor loss caused by the copper foil and the dielectric loss caused by the insulating resin base material.

Conductor losses may increase due to the skin effect of copper foil, which appears more prominently at higher frequencies. Therefore, in order to suppress transmission loss in high-frequency applications, the smoothing of copper foil and the miniaturization of roughened particles are pursued to reduce the skin effect of copper foil. In this regard, roughened copper foil for the purpose of reducing transmission loss is known. For example, it is disclosed in Patent Document 4 (Patent No. 6462961): Regarding the following surface-treated copper foil, that is, on at least one surface of the copper foil, a roughening treatment layer, an anti-rust treatment layer, and a silane coupling layer are formed accordingly For those formed by sequential lamination, the expansion area ratio Sdr of the interface measured from the surface of the silane coupling layer is 8% to 140%, the root mean square surface gradient Sdq is 25° to 70°, and the aspect ratio Str of the surface texture It is not less than 0.25 and not more than 0.79. According to the said surface-treated copper foil, the transmission loss of a high-frequency electric signal is small, and it can manufacture the printed wiring board which has excellent adhesiveness at the time of reflow soldering. [Prior Art Literature] [Patent Document]

[Patent Document 1] International Publication No. 2016/117587 [Patent Document 2] Japanese Patent Laid-Open No. 2018-26590 [Patent Document 3] International Publication No. 2020/031721 [Patent Document 4] Japanese Patent No. 6462961

As described above, from the viewpoint of high-frequency transmission, copper foil with less transmission loss (that is, copper foil excellent in high-frequency characteristics) is required as a material for forming circuit wiring for transmitting signals. Although it is considered that the transmission loss can be suppressed by smoothing the copper foil and miniaturizing the roughened particles, the physical adhesion between the copper foil and the substrate resin (especially the shear strength) decreases. In this way, it is not easy to balance excellent transmission characteristics and high circuit adhesion.

The inventors of the present invention have obtained the following knowledge: in roughened copper foil, by giving the sum of the heights of the peaks and valleys calculated as the sum of the volumes of the peaks and the volumes of the valleys, and the average height of the peaks and the valleys The average heights of the peaks and valleys calculated by the sum of the average heights are respectively controlled in a specific range of the surface profile, and in the processing of copper foil laminates or the manufacture of printed wiring boards, excellent transmission characteristics and high shear resistance can be taken into account strength.

Therefore, an object of the present invention is to provide a roughened copper foil capable of achieving both excellent transmission characteristics and high shear strength in the processing of copper-clad laminates or the manufacture of printed wiring boards.

According to the present invention, the following aspects are provided. [Aspect 1] A roughened copper foil having a roughened surface on at least one side, the roughened surface having a plurality of peaks that are convex with respect to a reference plane and a plurality of concaves with respect to the reference plane The valley is calculated as the sum of the volume of the peak and the volume of the valley in the analysis area of 2000 nm×2000 nm when analyzing the three-dimensional image of the image obtained by using FIB-SEM on the roughened surface The sum of the heights of the peaks and valleys is 1.4×10 ⁸ nm ³ or more and 3.5×10 ⁸ nm ³ or less, and the average height of the peaks and valleys calculated as the sum of the average height of the peaks and the average height of the valleys is 40 nm or more Below 90nm. [Aspect 2] The roughened copper foil according to Aspect 1, wherein the sum of the heights of the aforementioned peaks and valleys is not less than 2.0×10 ⁸ nm ³ and not more than 3.5×10 ⁸ nm ³ . [Aspect 3] The roughened copper foil according to Aspect 1 or 2, wherein the average height of the aforementioned peaks and valleys is not less than 40 nm and not more than 80 nm. [Aspect 4] The roughened copper foil according to any one of Aspects 1 to 3, wherein when the image obtained by using FIB-SEM on the aforementioned roughened surface is subjected to three-dimensional image analysis, every 1 nm ² The total volume of the aforementioned peaks per unit area is not less than 7.0 nm ³ and not more than 50.0 nm ³ . [Aspect 5] The roughened copper foil according to Aspect 4, wherein the total volume of the aforementioned peaks per unit area of 1 nm ² is not less than 30.0 nm ³ and not more than 50.0 nm ³ . [Aspect 6] The roughened copper foil according to any one of Aspects 1 to 5, wherein three-dimensional image analysis is performed on the image obtained on the roughened surface using FIB-SEM and the peak is divided into When there are multiple voxels, the ratio of the total volume of the voxels constituting the surface of the aforementioned peak to the total volume of all voxels constituting the aforementioned peak within the analytical region of 2000 nm×2000 nm, that is, the surface voxel ratio is not less than 0.25 and not more than 0.60. [Aspect 7] The roughened copper foil according to Aspect 6, wherein the surface voxel ratio is not less than 0.25 and not more than 0.35. [Aspect 8] The roughened copper foil according to any one of Aspects 1 to 7, further comprising an antirust treatment layer and/or a silane coupling agent layer on the roughened surface. [Aspect 9] A copper foil with a carrier, which includes: a carrier; a release layer provided on the carrier; and the roughened copper foil according to any one of Aspects 1 to 8, which has a It is arranged on the peeling layer for the outside. [Aspect 10] A copper foil laminate including the roughened copper foil according to any one of Aspects 1 to 8. [Aspect 11] A printed wiring board including the roughened copper foil according to any one of Aspects 1 to 8.

Definitions The definitions of the terms or parameters used to specify the present invention are shown below.

In this specification, the so-called "image obtained on the roughened surface using FIB-SEM" refers to the roughened surface of the roughened copper foil, which is processed by FIB (focused ion beam) and utilized. The aggregate of cross-sectional images obtained through cross-sectional observation by SEM (Scanning Electron Microscope) constitutes three-dimensional shape data as a whole. Specifically, as shown in FIG. 7 , when the x-axis and the z-axis are defined as the in-plane direction of the roughened copper foil 10, and the y-axis is defined as the thickness direction of the roughened copper foil 10, the relationship between x-y A cross-sectional image of the roughened copper foil 10 including the roughened surface at the cutting surface S parallel to the surface, so that the cutting surface is moved in parallel along the z-axis direction at a specific interval (for example, 10 nm), and in a specific analysis area An aggregate of cross-sectional images (for example, a total of 1000 pieces) obtained within (for example, 2000 nm×2000 nm).

In this specification, the so-called "peak" of the roughened surface, as shown schematically in FIGS. convex part. In addition, in this specification, the so-called "valley" of the roughened surface, as shown schematically in FIGS. Surface R becomes part of the recess. The "reference plane" of the roughened surface can be specified by performing three-dimensional image analysis on the image obtained for the roughened surface using FIB-SEM. Specifically, first, within the analysis area (size when viewed from above) of 2000 nm×2000 nm, for one pixel in the x-z plane of the image constituting the concave-convex structure (hereinafter referred to as the pixel of interest), obtain the The pixel is the central value (reference point) of the height (y direction) of the roughened surface in a specific matrix size (for example, 99) in the x-z plane of the center. For example, when the matrix size is 99, it means that the median value is obtained from the height of each roughened surface of 99 pixels×99 pixels centered on the pixel of interest. This operation is performed on all pixels in the x-z plane of the image forming the concave-convex structure (each pixel is the pixel of interest), and the median (reference point) of the height of the roughened surface of each pixel of interest is obtained. Then, a plane passing through all the reference points of each pixel of interest obtained in this way can be created and set as a reference plane. The above-mentioned three-dimensional image analysis can be carried out automatically using commercially available software, and the reference plane (ie, In the setting of the reference plane in the commercially available software, there are no items that can be set arbitrarily except for the matrix size). For example, for the image of the roughened surface (the cut image of the 3D shape data of the roughened copper foil), the 3D positioning software "ExFact Slice Aligner (version 2.0)" (manufactured by VISUAL SCIENCE Co., Ltd., Japan) and the 3D The image analysis software "ExFact VR (Version 2.2)" and "foil Analysis (Version 1.0)" (both manufactured by VISUAL SCIENCE Co., Ltd., Japan) performed image analysis in accordance with the conditions described in the Examples of this specification. In addition, the method for obtaining cross-sectional images obtained using FIB-SEM will be shown in Examples described later.

In this specification, the "sum of the heights of peaks and valleys" is a parameter representing the sum of the volumes of peaks and valleys within an analysis region (dimensions when viewed from above) of 2000 nm×2000 nm. That is, as schematically shown in FIG. 3, the sum of the peak volumes Ap with respect to the reference plane R (the total volume of all peaks in the analysis region) and the sum of the volumes Av of the valleys with respect to the reference plane R ( The sum of the total volume of all valleys in the analytical area) is equivalent to the sum of the heights of peaks and valleys. Furthermore, "the sum of the heights of peaks and valleys" can also be referred to as "the sum of the volumes of peaks and valleys", because in the manuals of commercially available image analysis software, the terms "height of peaks" and "valleys" are used. Therefore, in this specification, the expression of "the sum of the heights of peaks and valleys" is intentionally used so that those familiar with this technology can easily carry out the measurement.

In this specification, the "average height of peaks and valleys" is a parameter representing the sum of the average height of peaks and the average height of valleys within an analysis area (dimensions in plan view) of 2000 nm×2000 nm. That is, as shown schematically in FIG. 4 , the average of the heights Hp of peaks relative to the reference plane R (the average height of all peaks in the analysis region) and the average of the heights Hv of valleys relative to the reference plane R (analysis The average height of all valleys in the area) is equivalent to the average height H of peaks and valleys.

In this specification, the so-called "total volume of peaks per unit area of ¹ nm" is calculated by comparing the total volume of all peaks in the analysis region (dimensions when viewed from above) of 2000 nm×2000 nm to the area of the analysis region The parameters calculated by division.

The sum of the heights of peaks and valleys, the average height of peaks and valleys, that is, the total volume of peaks per 1 ^nm2 unit area, can be analyzed by performing three-dimensional image analysis on the image obtained for the roughened surface using FIB-SEM rather specific. Such three-dimensional image analysis can be performed using commercially available software. For example, for the cross-sectional image of the roughened surface (the cutting image of the 3D shape data of the roughened copper foil), the 3D positioning software "ExFact Slice Aligner (version 2.0)" (manufactured by VISUAL SCIENCE Co., Ltd., Japan) and The three-dimensional image analysis software "ExFact VR (version 2.2)" and "foil Analysis (version 1.0)" (both manufactured by Japan Visual Science Co., Ltd.) perform image analysis in accordance with the conditions described in the examples of this manual. In addition, the method for obtaining cross-sectional images obtained using FIB-SEM will be shown in Examples described later.

In this specification, the so-called "voxel" is an element of volume in three-dimensional image data, and is a concept corresponding to a pixel of two-dimensional image data. Voxels can be represented by cubes or cuboids. For example, each voxel has a size such as (vertical, horizontal, height) = (1 nm, 1 nm, 1 nm), so it can be converted into SI units.

In this specification, the so-called "surface voxel ratio" refers to the volume of the surface constituting the peak in the analysis area (size when viewed from above) of 2000 nm×2000 nm when the peak of the roughened surface is divided into plural voxels The ratio of the total volume of the element (surface voxel) to the total volume of all voxels making up the peak. The surface voxel ratio can be specified by three-dimensional image analysis of the image obtained for the roughened surface using FIB-SEM. Specifically, as shown schematically in FIG. 5 , for the image obtained for the roughened surface using FIB-SEM, as shown in FIG. 8 , the z-axis is perpendicular to the roughened surface, And the x-axis, y-axis, and z-axis are assigned in such a way that the xy plane and the roughened surface are parallel, and the three-dimensional image analysis is performed, and the peaks (P ₁ , P ₂ , P ₃ ) existing on the roughened surface are borrowed The voxel B is hypothetically partitioned (labelled). In this case, the voxel constituting the surface of the peak (the surface in contact with the atmosphere) among the voxels constituting the peak is defined as "surface voxel Bs", thereby calculating the surface voxel ratio. Such three-dimensional image analysis can be performed using commercially available software. For example, for the image of the roughened surface (the cut image of the 3D shape data of the roughened copper foil), the 3D positioning software "ExFact Slice Aligner (version 2.0)" (manufactured by VISUAL SCIENCE Co., Ltd., Japan) and the 3D The image analysis software "ExFact VR (Version 2.2)" and "foil Analysis (Version 1.0)" (both manufactured by VISUAL SCIENCE Co., Ltd., Japan) performed image analysis in accordance with the conditions described in the Examples of this specification. In addition, the method for obtaining cross-sectional images obtained using FIB-SEM will be shown in Examples described later.

In this specification, the "electrode surface" of the carrier refers to the surface on the side that contacts the cathode when the carrier is fabricated.

In this specification, the so-called "precipitation surface" of the carrier refers to the surface on which the electrolytic copper is continuously deposited during the production of the carrier, that is, the surface on the side that is not in contact with the cathode.

Roughening treatment copper foil The copper foil of this invention is a roughening treatment copper foil. The roughened copper foil has a roughened surface on at least one side. The roughened surface has a plurality of peaks that are convex with respect to the reference plane and a plurality of valleys that are concave with respect to the reference plane. Furthermore, when a three-dimensional image analysis is performed on an image obtained on a roughened surface using FIB-SEM, the sum of the volume of the peak and the volume of the valley calculated as the sum of the volume of the peak and the volume of the valley in the analysis area of 2000 nm × 2000 nm The sum of the heights is not less than 1.4×10 ⁸ nm ³ and not more than 3.5×10 ⁸ nm ³ . Also, the average height of peaks and valleys calculated as the sum of the average height of peaks and the average height of valleys in the analysis region of 2000 nm×2000 nm is not less than 40 nm and not more than 90 nm. In this way, in the roughened copper foil, by giving the surface profile that controls the sum of the heights of the peaks and valleys, and the average height of the peaks and valleys to specific ranges, it can be used in the processing or printing of copper foil laminates. In the manufacture of boards, excellent transmission characteristics (especially excellent high-frequency characteristics) and high shear strength (and thus high circuit adhesion from the perspective of shear strength) can be taken into account.

It is difficult to balance the excellent transmission characteristics and high shear strength. This is because, as mentioned above, in order to obtain excellent transmission characteristics, the smoothness of copper foil and the miniaturization of roughened particles are generally pursued, but on the other hand, in order to improve the shear strength of the circuit, generally large rough Because of the particles. Regarding this point, the inventors of the present invention found after research that the roughened shape can be controlled by three-dimensionally evaluating the roughened copper foil, and although it is a fine uneven structure that is advantageous in reducing transmission loss, it can be ideally Maintain the adhesion between copper foil and substrate. Furthermore, it was found that such a concavo-convex structure can be realized by controlling the sum of the heights of the peaks and valleys, and the average height of the peaks and valleys, respectively, within specific ranges.

Although the mechanism is not necessarily clear, the following contents can be considered. That is, as mentioned above with reference to FIG. 3 , the sum of the heights of the peaks and valleys represents the total volume of the peaks and valleys with respect to the reference plane R, which roughly corresponds to the portion in contact with the substrate (the portion that bites into the substrate) part) volume. Therefore, the greater the sum of the heights of the peaks and valleys, the greater the volume of the portion in contact with the substrate, and thus correlates with an increase in shear strength. In addition, as mentioned above while referring to FIG. 4 , the average height of peaks and valleys represents the sum of the average peak height and the average valley height with respect to the reference plane R. That is, the smaller the average height of the peaks and valleys, the smaller the unevenness of the surface. Furthermore, if the surface irregularities are small, even if the skin depth becomes smaller due to high frequency, the current path will not be easily affected by the surface irregularities, leading to a reduction in transmission loss. Therefore, by controlling both the sum of the heights of the peaks and valleys and the average heights of the peaks and valleys in the roughened surface within specific ranges, when used in copper foil laminates or printed wiring boards, it is possible to balance It can achieve excellent transmission characteristics and high shear strength with good performance.

On the other hand, in the prior art, the roughened shape was evaluated using a laser microscope, but in this method, there is a limit to accurately evaluating the characteristics of the minute roughened shape. Here, FIG. 6 schematically shows an example of measurement of a roughened surface with a laser microscope. As shown in FIG. 6 , in the measurement with a laser microscope, laser light is irradiated from above the roughened surface. At this time, there is a region N where laser light cannot enter due to being blocked by the roughening particles 10a. Due to this region N, it may be difficult to accurately evaluate features such as the surface area or volume of peaks and valleys in the measurement of the roughened surface using a laser microscope. This problem becomes conspicuous when a fine roughened shape that achieves both excellent transmission characteristics and high circuit adhesion is pursued. Also, in the prior art, a method of three-dimensionally evaluating a sample has been studied, but it is not sufficient as an evaluation method capable of achieving both excellent transport characteristics and high shear strength. On the other hand, in the present invention, focusing on the sum of the heights of the peaks and valleys, and the average height of the peaks and valleys, and controlling them within appropriate ranges, it can be used in copper foil laminates or printed wiring When using the board, it can take into account the excellent transmission characteristics and high shear strength.

Based on the viewpoint of achieving high shear strength, the sum of the heights of the peaks and valleys on the roughened surface of the roughened copper foil is 1.4×10 ⁸ nm ³ or more and 3.5×10 ⁸ nm ³ or less. The point of view of further improvement of shear strength is 2.0×10 ⁸ nm ³ to 3.5×10 ⁸ nm ³ , or the point of view of further improvement of transmission characteristics is 1.4×10 ⁸ nm ³ to 1.8×10 ⁸ nm ³ .

Based on the viewpoint of achieving excellent transmission characteristics, the average height of the peaks and valleys in the roughened surface of the roughened copper foil is not less than 40 nm and not more than 90 nm, preferably not less than 40 nm and not more than 80 nm, and more preferably, From the point of view of further improvement of transmission characteristics, it is 40 nm to 50 nm, or from the point of view of further improvement of shear strength, it is 70 nm to 80 nm.

The total volume of peaks per 1 nm ² unit area of the roughened copper foil is preferably 7.0 nm ³ to 50.0 nm ³ , more preferably 30.0 nm ³ to 50.0 nm ³ . Thereby, when it is used for a copper-clad laminated board or a printed wiring board, a further higher shear strength can be realized.

From the point of view of achieving high shear strength, the surface voxel ratio in the roughened surface of the roughened copper foil is preferably 0.25 to 0.60, more preferably 0.25 from the point of view of further improvement of the shear strength The above is 0.35 or less, or it is 0.40 or more and 0.60 or less from the viewpoint of further improvement of transmission characteristics.

Although the mechanism of increasing the shear strength by controlling the surface volume ratio is not necessarily clear, the following contents can be considered. Here, FIG. 5 schematically shows an example in which the peaks (P ₁ , P ₂ , P ₃ ) existing on the roughened surface of the roughened copper foil 10 are virtually divided by the voxel B. The total volumes of peak P ₁ , peak P ₂ and peak P ₃ shown in FIG. 5 are the same, therefore, the number of voxels B that respectively partition these peaks is also the same (20). On the other hand, in peak P ₁ , peak P ₂ and peak P ₃ , the surface voxels Bs (voxels located at the most surface part in contact with the resin) constituting the surface of the peaks were 20, 14, and 10, respectively, Therefore, the ratio of surface voxels (the ratio of the total volume of surface voxels to the total volume of all voxels) is 1.0 (=20/20), 0.7 (=14/20), and 0.5 (=10/20) respectively. . Moreover, because the volume ratio (the ratio of the volume except the surface voxel) occupied in the transverse direction (the direction shown by the arrow in Fig. 5) according to the order of peak _P3 , peak _P2 , and peak _P1 is large , so it can withstand a greater force from the lateral direction in this order (that is, the shear strength is greater in the order of peak P ₃ , peak P ₂ , and peak P ₁ ). That is, when the total volume of the peaks is the same, it can be said that the smaller the surface voxel ratio, the higher the shear strength. It is considered that the part composed only of surface voxels is brittle and easy to break, so it has little effect on the shear strength. If only the width of the peak of the roughened surface is indicated, it will also include a part composed of only surface voxels that have little influence on the shear strength, so it is not sufficient to establish a corresponding relationship with the shear strength. Therefore, the shear strength is preferably expressed by the surface voxel ratio. Also, from the viewpoint of achieving a balance between excellent transmission characteristics, it is desirable to control the surface voxel ratio within the above-mentioned range while achieving a balance with the average height of peaks and valleys.

The thickness of the roughened copper foil is not particularly limited, but it is preferably from 0.1 μm to 35 μm, more preferably from 0.5 μm to 5.0 μm, especially preferably from 1.0 μm to 3.0 μm. In addition, the roughening process copper foil is not limited to the thing which roughened the surface of the normal copper foil, The thing which roughened the copper foil surface of the copper foil with a carrier may be sufficient. Here, the thickness of the roughened copper foil is a thickness not including the height of the roughened particles formed on the surface of the treated surface (thickness of the copper foil itself constituting the roughened copper foil). Copper foil having a thickness in the above range may be called ultra-thin copper foil.

The roughened copper foil has a roughened surface on at least one side. That is, the roughened copper foil may have a roughened surface on both sides, or may have a roughened surface only on one side. Typically, the roughened surface has a plurality of roughened particles (protrusions), and each of the plurality of roughened particles preferably contains copper particles. Copper particles may contain metallic copper or may contain a copper alloy.

Roughening treatment for forming a roughened surface can be preferably performed by forming roughening particles using copper or a copper alloy on copper foil. The roughening treatment is preferably performed according to a plating method through three-stage plating steps. In this case, in the plating step of the first stage, it is preferable to use a copper sulfate solution with a copper concentration of 5 g/L to 15 g/L and a sulfuric acid concentration of 200 g/L to 250 g/L. Electrodeposition is carried out under the plating conditions of a liquid temperature of 25°C to 45°C and a current density of 2 A/dm ² to 4 A/dm ² . In particular, it is preferable to perform the plating step of the first stage twice in total using two tanks. In the plating step of the second stage, it is preferable to use a copper sulfate solution with a copper concentration of 60 g/L to 80 g/L and a sulfuric acid concentration of 200 g/L to 260 g/L. Electrodeposition is carried out under the plating conditions of above 55°C and current density of 10 A/dm ² to 15 A/dm ² . In the plating step of the third stage, it is preferable to use a copper concentration of 5 g/L to 20 g/L, a sulfuric acid concentration of 60 g/L to 90 g/L, and a chlorine concentration of 20 mg/L to 40 mg. Copper sulfate solution with a concentration of 9-phenylacridine (9PA) of 100 mg/L or more and 200 mg/L or less, with a liquid temperature of 25°C or more and 35°C or less, and a current density of 30 A/dm ² or more and 60 A Electrodeposition is carried out under the plating conditions below /dm ² . Each plating step of the second stage and the third stage can be performed twice in total using two tanks, and it is preferable to complete it once in total. By going through such a plating step, it is easy to form more suitable protrusions on the treated surface to satisfy the above-mentioned surface parameters.

If desired, antirust treatment may be given to the roughened copper foil to form an antirust treatment layer. The antirust treatment preferably includes plating treatment using zinc. The plating treatment using zinc may be any one of zinc plating treatment and zinc alloy plating treatment, especially zinc-nickel alloy treatment of zinc alloy plating treatment. The zinc-nickel alloy treatment may be a plating treatment including at least Ni and Zn, and other elements such as Sn, Cr, Co, and Mo may be further included. The Ni/Zn adhesion ratio in the zinc-nickel alloy plating is preferably from 1.2 to 10 in mass ratio, more preferably from 2 to 7, and especially preferably from 2.7 to 4. In addition, it is preferable that the antirust treatment further includes chromate treatment, and it is more preferable that the chromate treatment is performed on the surface of the plating including zinc after the plating treatment using zinc. Thereby, rust resistance can be further improved. A particularly preferred antirust treatment is a combination of zinc-nickel alloy plating followed by chromate treatment.

A silane coupling agent treatment may also be applied to the surface of the roughened copper foil as desired to form a silane coupling agent layer. Thereby, moisture resistance, chemical resistance, adhesiveness with an adhesive, etc. can be improved. The silane coupling agent layer can be formed by appropriately diluting the silane coupling agent, applying it, and drying it. Examples of silane coupling agents include epoxy-functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane and 3-glycidyloxytrimethoxysilane, or 3-aminopropyl Trimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy)propyl- Amino-functional silane coupling agents such as 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, etc., or mercapto-functional silanes such as 3-mercaptopropyltrimethoxysilane Olefin-functional silane coupling agents such as vinyltrimethoxysilane and vinylphenyltrimethoxysilane, or acrylic-functional silane coupling agents such as 3-methacryloxypropyltrimethoxysilane , or imidazole functional silane coupling agents such as imidazole silane, or triazine functional silane coupling agents such as triazine silane, etc.

Based on the above reasons, the roughened copper foil is preferably further equipped with an anti-rust treatment layer and/or a silane coupling agent layer on the roughened surface, and more preferably has both an anti-rust treatment layer and a silane coupling agent layer. . The antirust treatment layer and the silane coupling agent layer may be formed not only on the roughened surface side of the roughened copper foil but also on the side where the roughened surface is not formed.

Copper foil with carrier As mentioned above, the roughened copper foil of this invention can be provided in the form of copper foil with a carrier. By adopting the form of copper foil with a carrier, excellent laser processability and fine line circuit formability can be realized. That is, according to a preferred aspect of the present invention, there is provided a copper foil with a carrier, which includes: a carrier; a release layer provided on the carrier; and the above-mentioned roughened copper foil, which is provided with the roughened surface as the outer side. on the release layer. However, the copper foil with a carrier may employ a known layer configuration other than the roughened copper foil of the present invention.

The support system is used to support the roughened copper foil to improve its handling. The typical support includes a metal layer. Examples of such a carrier include aluminum foil, copper foil, stainless steel (SUS) foil, a resin film or glass whose surface is coated with a metal such as copper, and copper foil is preferred. The copper foil may be any one of rolled copper foil and electrolytic copper foil, preferably electrolytic copper foil. The thickness of the carrier is typically not more than 250 μm, preferably not less than 7 μm and not more than 200 μm.

The surface of the carrier on the release layer side is preferably smooth. That is, in the manufacturing process of copper foil with carrier, an ultra-thin copper foil (before roughening treatment) is formed on the surface of the carrier on the release layer side. When the roughened copper foil of the present invention is used in the form of copper foil with a carrier, the roughened copper foil can be obtained by roughening such an ultra-thin copper foil. Therefore, by smoothing the surface of the carrier on the side of the peeling layer in advance, the surface of the outer side of the ultra-thin copper foil can also be smoothed, and it can be easily realized by roughening the smooth surface of the ultra-thin copper foil. A roughened surface having the sum of the heights of the peaks and valleys and the average height of the peaks and valleys within the above specified range. In order to smoothen the surface of the release layer side of the carrier, for example, it is possible to adjust the surface roughness by polishing the surface of the cathode used in the electrolytic foiling of the carrier with a specific type of polisher. That is, the surface profile of the cathode adjusted in this way is transferred to the electrode surface of the carrier, and an ultra-thin copper foil is formed on the electrode surface of the carrier through a release layer, and the outer surface of the ultra-thin copper foil can be processed. The surface provides a smooth surface state that facilitates the above-mentioned roughened surface. The preferred type of polishing is above #2000 and below #3000, more preferably above #2000 and below #2500. Compared with the smooth foil deposition surface, the electrode surface of the carrier obtained by using a cathode polished by a polishing machine of the type above #2000 and below #2500 can ensure adhesion and smoothness due to slight fluctuations, and can be more smooth. Well-balanced to achieve high adhesion and excellent transmission characteristics. In addition, based on the viewpoint of making the ultra-thin copper foil smoother and controlling various surface parameters of the obtained roughened copper foil more easily within the above range, it is possible to use an electrolyte solution containing additives for electrolytic foil production. The side of the precipitation side is used as the side of the release layer of the carrier.

The peeling layer is a map that has the following functions: weakening the peeling strength of the carrier, ensuring the stability of the strength, and inhibiting the interdiffusion that may occur between the carrier and the copper foil during press molding at high temperature. The release layer is generally formed on one side of the carrier, and may be formed on both sides. The peeling layer may be any one of an organic peeling layer and an inorganic peeling layer. Examples of the organic component used in the organic release layer include nitrogen-containing organic compounds, sulfur-containing organic compounds, and carboxylic acids. Examples of nitrogen-containing organic compounds include triazole compounds, imidazole compounds, and the like, and among them, triazole compounds are preferable because the detachability is easily stabilized. Examples of triazole compounds include 1,2,3-benzotriazole, carboxybenzotriazole, N',N'-bis(benzotriazolylmethyl)urea, 1H-1,2 , 4-triazole and 3-amino-1H-1,2,4-triazole, etc. Examples of sulfur-containing organic compounds include mercaptobenzothiazole, thiocyanuric acid, and 2-benzimidazolethiol. As an example of a carboxylic acid, a monocarboxylic acid, a dicarboxylic acid, etc. are mentioned. On the other hand, Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, chromate treatment film, etc. are mentioned as an example of the inorganic component used for an inorganic peeling layer. Furthermore, the formation of the release layer can be carried out by bringing a solution containing the release layer components into contact with at least one surface of the carrier to fix the release layer components on the surface of the carrier, or the like. When the carrier is brought into contact with the solution containing the components of the release layer, the contact can be performed by immersing the solution containing the components of the release layer, spraying the solution containing the components of the release layer, or pouring the solution containing the components of the release layer. In addition, a method of forming a peeling layer component on a film by a gas phase method such as vapor deposition or sputtering can also be used. Also, the release layer components can be fixed to the carrier surface by adsorption or drying of the solution containing the release layer components, electrodeposition of the release layer components in the solution containing the release layer components, or the like. The thickness of the release layer is typically not less than 1 nm and not more than 1 μm, preferably not less than 5 nm and not more than 500 nm.

Other functional layers can also be provided between the release layer and the carrier and/or the roughened copper foil as desired. An example of such another functional layer is an auxiliary metal layer. The auxiliary metal layer preferably includes nickel and/or cobalt. By forming such an auxiliary metal layer on the surface side of the carrier and/or the surface side of the roughened copper foil, it is possible to suppress the possibility of a gap between the carrier and the roughened copper foil during high-temperature or long-term thermocompression forming. The resulting interdiffusion ensures the stability of the peel strength of the carrier. The thickness of the auxiliary metal layer is preferably set to not less than 0.001 μm and not more than 3 μm.

Copper Foil Laminated Board The roughened copper foil of the present invention is preferably used in the production of copper foil laminated boards for printed wiring boards. That is, according to a preferable aspect of this invention, the copper foil laminated board provided with the said roughening process copper foil is provided. By using the roughened copper foil of the present invention, both excellent transmission characteristics and high shear strength can be achieved in the processing of copper foil laminates. This copper foil laminate is equipped with the roughening process copper foil of this invention, and the resin layer provided in close contact with the roughening process surface of the roughening process copper foil. The roughened copper foil can be provided on one side of the resin layer or on both sides. The resin layer contains resin, preferably insulating resin. The resin layer is preferably a prepreg and/or a resin sheet. The so-called prepreg is a general term for composite materials obtained by impregnating base materials such as synthetic resin plates, glass plates, glass woven fabrics, glass non-woven fabrics, and paper with synthetic resins. Preferable examples of insulating resins include epoxy resins, cyanate resins, bismaleimide triazine resins (BT resins), polyphenylene ether resins, and phenol resins. Moreover, examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resins, polyimide resins, and polyester resins. In addition, from the viewpoint of improving insulation and the like, the resin layer may contain filler particles including various inorganic particles such as silicon oxide and aluminum oxide. The thickness of the resin layer is not particularly limited, but it is preferably from 1 μm to 1000 μm, more preferably from 2 μm to 400 μm, and most preferably from 3 μm to 200 μm. The resin layer may consist of a plurality of layers. The resin layer of the prepreg and/or the resin sheet can be provided on the roughened copper foil through the primer resin layer coated on the surface of the copper foil in advance.

Printed Wiring Board The roughened copper foil of the present invention is preferably used in the manufacture of printed wiring boards. That is, according to a preferable aspect of this invention, the printed wiring board provided with the said roughening process copper foil is provided. By using the roughened copper foil of the present invention, both excellent transmission characteristics and high shear strength can be achieved in the manufacture of printed wiring boards. The printed wiring board of this aspect includes the layer structure which laminated|stacked the resin layer and the copper layer. The copper layer is a layer derived from the roughened copper foil of the present invention. In addition, the resin layer is as above-mentioned about the copper foil laminated board. In short, a well-known layer structure can also be used for a printed wiring board other than using the roughened copper foil of this invention. Specific examples related to printed wiring boards include printed wiring boards on one or both sides of which a circuit is formed after the roughened copper foil of the present invention is adhered to one or both sides of a prepreg and hardened to form a laminate, Or a multilayer printed wiring board made of these multilayers. Moreover, as still another specific example, the roughened copper foil of this invention was formed on the resin film, and the flexible printed wiring board which formed the circuit, COF, TAB tape, etc. are mentioned. Furthermore, as yet another specific example, the above-mentioned resin layer is applied to the roughened copper foil of the present invention to form a resin-attached copper foil (RCC), and the resin layer is used as an insulating adhesive material to be laminated on the above-mentioned After printing the substrate, use the roughened copper foil as all or part of the wiring layer to form a build-up wiring board using the modified semi-additive (MSAP) method, removal method, etc., or to remove the roughened copper foil A build-up wiring board that uses a semi-additive method to form a circuit, alternately repeating the build-up of resin-coated copper foil and the direct build-up on wafer (Direct build-up on wafer) formed by the circuit on the semiconductor integrated circuit. Specific examples of further development include antenna elements in which the above-mentioned resin-attached copper foil is laminated on a substrate to form a circuit, a panel in which a pattern is formed by laminating on glass or a resin film via an adhesive, electronic materials for displays, or windows. Electronic material for glass, electromagnetic wave shielding film formed by coating conductive adhesive on roughened copper foil of the present invention, etc. In particular, the printed wiring board provided with the roughened copper foil of the present invention is preferably used in automotive antennas, mobile phone base station antennas, high-performance servers, anti-corrosion High-frequency substrates used in applications such as collision radar. In particular, the roughened copper foil of the present invention is suitable for the MSAP method. For example, the configurations shown in FIGS. 1 and 2 can be used when forming a circuit by the MSAP method. [Example]

The present invention is described more specifically by the following examples.

Examples 1 , 2 , and 4 produced copper foil with a carrier having a roughened copper foil as follows.

(1) Preparation of the carrier Use the copper electrolyte, cathode, and DSA (dimensionally stable anode) as the anode to perform electrolysis at a solution temperature of 50°C and a current density of 70 A/dm ² , with a thickness of 18 μm electrolytic copper foil is used as the carrier. At this time, as a cathode, an electrode whose surface was polished with a #2000 polisher and whose surface roughness was adjusted was used. <Composition of Copper Electrolyte> - Copper concentration: 80 g/L - Sulfuric acid concentration: 300 g/L - Chlorine concentration: 30 mg/L - Glue concentration: 5 mg/L

(2) Formation of peeling layer Put the electrode surface of the acid-washed carrier in a CBTA aqueous solution containing carboxybenzotriazole (CBTA) concentration of 1 g/L, sulfuric acid concentration of 150 g/L and copper concentration of 10 g/L, at a liquid temperature of 30°C Immerse for 30 seconds to make the CBTA component adsorb on the electrode surface of the carrier. In this way, the CBTA layer was formed as an organic release layer on the electrode surface of the carrier.

(3) Formation of the auxiliary metal layer Immerse the carrier forming the organic release layer in a solution containing nickel concentration of 20 g/L made of nickel sulfate, under the conditions of liquid temperature 45°C, pH 3, and current density 5 A/dm ² Next, nickel was deposited on the organic release layer in an amount corresponding to a thickness of 0.001 μm. In this way, the nickel layer was formed as the auxiliary metal layer on the organic release layer.

(4) Formation of ultra-thin copper foil Immerse the carrier with the auxiliary metal layer in the copper solution of the composition shown below, and perform electrolysis at a solution temperature of 50°C and a current density of 5 A/ ^dm2 to 30 A/ ^dm2 , and an ultra-thin copper foil with a thickness of 1.5 μm is formed on the auxiliary metal layer. ＜Solution composition＞ - Copper concentration: 60 g/L - Sulfuric acid concentration: 200 g/L

(5) Coarsening treatment Copper foil with a carrier is obtained by forming a roughened copper foil by roughening the surface of the ultra-thin copper foil thus formed. In this roughening process, with respect to Examples 1 and 2, three steps of roughening process shown below were performed. - The coarsening treatment of the first stage is divided into 2 times. Specifically, using the acidic copper sulfate solution having the copper concentration and sulfuric acid concentration shown in Table 1, the roughening treatment was performed twice at the current density and liquid temperature shown in Table 1. ‐ The roughening treatment of the second stage uses the acidic copper sulfate solution with the copper concentration and sulfuric acid concentration shown in Table 1, and performs the roughening treatment at the current density and liquid temperature shown in Table 1. ‐ The coarsening treatment of the third stage uses the acidic copper sulfate solution with the copper concentration, sulfuric acid concentration, chlorine concentration and 9-phenylacridine (9PA) concentration shown in Table 1, and the current density and liquid temperature shown in Table 1 Coarse processing is performed below.

On the other hand, for Example 4, two stages of roughening treatment were performed. The two-stage roughening process includes a firing plating step for depositing and attaching fine copper particles on the ultra-thin copper foil, and an overcoating plating step for preventing the fine copper particles from falling off. In the firing plating step, carboxybenzotriazole (CBTA) was added to the acidic copper sulfate solution having a copper concentration of 10 g/L and a sulfuric acid concentration of 200 g/L so as to have the concentration shown in Table 1. Coarsening was performed at the indicated current densities and liquid temperatures. In the subsequent outer plating step, use an acidic copper sulfate solution with a copper concentration of 70 g/L and a sulfuric acid concentration of 240 g/L, under smooth plating conditions with a liquid temperature of 52°C and a current density shown in Table 1. Conduct electrodeposition.

(6) Antirust treatment The roughened surface of the obtained copper foil with a carrier was subjected to antirust treatment including zinc-nickel alloy plating treatment and chromate treatment. First, use a solution containing a zinc concentration of 1 g/L, a nickel concentration of 2 g/L, and a potassium pyrophosphate concentration of 80 g/L to roughen the layer at a liquid temperature of 40°C and a current density of 0.5 A/ ^dm2 . And the surface of the carrier is treated with zinc-nickel alloy plating. Then, using an aqueous solution containing 1 g/L of chromic acid, under the conditions of pH 12 and current density 1 A/dm ² , chromate treatment was performed on the surface treated with zinc-nickel alloy plating.

(7) Silane coupling agent treatment The aqueous solution containing a commercially available silane coupling agent is adsorbed on the surface of the copper foil with a carrier on the roughened copper foil side, and the silane coupling agent treatment is performed by evaporating water with an electric heater. At this time, the silane coupling agent treatment is not performed on the carrier side.

Example 3 Except the following a) and b), it carried out similarly to Example 1, and produced the roughening process copper foil. a) Instead of the copper foil with a carrier, roughen the deposition surface of the following electrolytic copper foil. b) The roughening treatment conditions were changed as shown in Table 1.

(Preparation of Electrolytic Copper Foil) As the copper electrolyte, a sulfuric acid copper sulfate solution with the composition shown below was used, a titanium electrode with a surface roughness Ra of 0.20 μm was used for the cathode, and DSA (dimensionally stable anode) was used for the anode. Electrolysis was performed at a solution temperature of 45°C and a current density of 55 A/dm ² to obtain an electrolytic copper foil with a thickness of 12 μm. <Composition of sulfuric acid acidic copper sulfate solution> - Copper concentration: 80 g/L - Sulfuric acid concentration: 260 g/L - Bis(3-sulfopropyl) disulfide concentration: 30 mg/L - Diallyl dimethyl Ammonium chloride copolymer concentration: 50 mg/L ‐ Chlorine concentration: 40 mg/L

Example 5 (Comparison) In the roughening process, the roughening treatment of the first and second stages was not performed, and the roughening treatment conditions of the third stage were changed as shown in Table 1, and it was carried out in the same manner as in Example 3. Production of roughened copper foil.

[Table 1] Table 1 Coarsening Conditions Phase 1 Phase 2 Phase 3 Current density (A/dm ² ) Copper (g/L) Sulfuric acid (g/L) CBTA (PPm) Liquid temperature(°C) Current density (A/dm ² ) Copper (g/L) Sulfuric acid (g/L) Liquid temperature(°C) Current density (A/dm ² ) Copper (g/L) Sulfuric acid (g/L) Chlorine (ppm) 9PA (ppm) Liquid temperature(°C) 1st 2nd example 1 2.1 2.1 11 230 - 35 11.0 69 250 51 30 13 72 36 139 28 Example 2 2.1 2.1 10.7 230 - 35 11.0 69 240 51 50 13 72 36 139 29 Example 3 2.1 2.1 10.7 240 - 35 11.0 69 240 52 55 7 65 29 130 28 Example 4* 21.8 - 10 200 33 25 3.4 70 240 52 - - - - - - Example 5* - - - - - - - - - - 45 13 82 35 139 27 * indicates a comparative example.

Evaluation Various evaluations shown below were performed on the roughened copper foil or the copper foil with a carrier produced in Examples 1-5.

(a) Three-dimensional image analysis parameters of the roughened surface By analyzing the three-dimensional image of the roughened copper foil or the copper foil with a carrier, the average height of the peaks and valleys, and the peaks and valleys are calculated. The sum of the heights, the surface voxel ratio, and the total volume of the peak per 1 nm ² unit area. The specific procedures are as follows.

(a-1) 3D-SEM observation Using a FIB-SEM device (Crossbeam540 manufactured by Carl Zeiss, SEM control: SmartSEM version 6.06 with service software group 8, FIB control: SmartFIB v1.11.0), for the area of 10240 nm×7680 nm on the roughened surface, in the following Acquisition of 3D shape data under measurement conditions. The three-dimensional shape data is acquired after setting the x-axis and z-axis as the in-plane direction of the roughened copper foil 10 and the y-axis as the thickness direction of the roughened copper foil 10 as shown in FIG. 7 . The cross-sectional images of the roughened copper foil 10 at the cutting plane S parallel to the x-y plane were moved parallelly by 10 nm along the z-axis direction, and a total of 1000 cross-sectional images were obtained in the above-mentioned analysis area. In addition, this time, observation was performed under the following conditions, but the observation conditions can be appropriately selected or changed according to the state of the apparatus (type, etc.).

＜SEM conditions＞ ‐Acceleration voltage: 1.0 kV ‐Working distance: 5mm ‐Tilt: 54° (with SEM image tilt correction) ‐Detector: InLens detector ‐Column Mode: High Resolution - Number of pixels: 2048 (x direction) ＜FIB conditions＞ ‐Acceleration voltage: 30 kV ‐Cutting thickness: 10 nm (interval between cutting surfaces S) ‐Voxel size setting: Such as (x, y, z) = (5 nm, 5 nm, 10 nm) to determine the voxel size to be set. The pixel size of x and y can be set by the FIB-SEM conditions, and the magnification is adjusted by multiplying the pixel number of FIB-SEM by the pixel size of x and y to become the scale of FIB-SEM. set up. If the number of pixels is 2048, and the x and y pixel sizes are 5 nm and 5 nm, adjust the magnification in such a way that 2048×5 nm=10240 nm becomes the scale of the x-axis of FIB-SEM. If the scale of the x-axis is determined, the scale of the y-axis is also determined. Since the voxel size of z is determined by the value of the cutting thickness (interval between cutting planes S), when z is set to be 10 nm, the cutting thickness is set to 10 nm. Furthermore, the determined voxel size can also be used to appropriately change the observation magnification through the device (model or software, etc.).

(a-2) 3D-SEM image analysis The cutting image obtained from the three-dimensional shape data of the roughened copper foil obtained by 3D-SEM uses the three-dimensional positioning software "ExFact Slice Aligner (version 2.0)" (manufactured by Japan Visual Science Co., Ltd.) to make the observation length of the z-axis 2 Correct the drift in the way of μm or more. For the cut image after drift correction, three-dimensional reconstruction was carried out using the three-dimensional image analysis software "ExFact VR (version 2.2)" (manufactured by Japan Visual Science Co., Ltd.). At this time, the analysis area is set to 2000 nm×1000 nm×2000 nm (2000 nm×2000 nm when the roughened copper foil 10 is viewed from above), and the size of each voxel is set to (x, y, z)=( 5 nm, 5 nm, 10 nm). Then, after rotating the axis so that the roughened surface becomes an x-y plane as shown in FIG. Various data related to the roughened surface were acquired as follows.

<Pre-analysis: Determination of peaks and valleys> For the three-dimensional reconstruction data, Otsu binarization is used to perform binarization, and the air and the roughened copper foil are separated. For the obtained binary data, the noise caused by the voids in the roughened copper foil and the cracks of the deposition when the 3D-SEM image was obtained was removed, and the uneven structure of the roughened copper foil was analyzed. A median filter was applied to the uneven structure of the obtained roughened copper foil, and a reference plane for the unevenness of the roughened surface was created. At this time, the matrix size of the median filter is set to 99. Then, a portion that becomes a convex portion with respect to the reference plane is defined as a peak, and a portion that becomes a concave portion with respect to the reference plane is defined as a valley. Label the peaks and valleys individually, and calculate the average height of the peaks and valleys, the sum of the heights of the peaks and valleys, the surface voxel ratio, and the total volume of the peaks per 1 ^nm2 unit area in the analysis region as follows .

<Average height of peaks and valleys in the analysis area> The sum of "plusMean" and "minusMean" calculated by the three-dimensional image analysis software "foil Analysis (version 1.0)" was used as the average height (voxel value) of peaks and valleys. Here, "plusMean" represents the mean value (voxel value) of the peak height, and "minusMean" represents the mean value (voxel value) of the valley height. The average height (nm) of peaks and valleys within the analysis region was calculated by multiplying the obtained average heights (voxel value) of peaks and valleys by the height per 1 voxel (ie, 5 nm). The results are as shown in Table 2.

<The sum of peak and valley heights> The sum of "plusSum" and "minusSum" calculated by the 3D image analysis software "foil Analysis (version 1.0)" was used as the sum of peak and valley heights (voxel value). Here, "plusSum" represents the sum of counted pixels (voxels) of peaks, and "minusSum" represents the sum of counted pixels (voxels) of valleys. The sum of the heights of the peaks and valleys in the analytical region ( nm ³ ). The results are as shown in Table 2.

＜Surface Voxel Ratio＞ As shown in FIG. 5 , a voxel constituting the surface (surface in contact with the atmosphere) of each tagged peak is referred to as a surface voxel Bs. Specifically, the "volume_voxels_sum" calculated using the "voidsSummary_kobu" Excel data generated by the analysis of the three-dimensional image analysis software "foil Analysis (version 1.0)" was used as the total volume of all voxels constituting the peak (voxel value ), use "surface_voxels_sum" as the total volume (voxel value) of the surface voxels Bs. The ratio of surface voxels in the resolved region was calculated by dividing the total volume of surface voxels Bs by the total volume of all voxels constituting the peak.

<Total volume of the peak per 1 ^nm2 unit area> The "volume_voxels_sum" calculated using the "voidsSummary_kobu" Excel data generated by the analysis of the three-dimensional image analysis software "foil Analysis (version 1.0)" was used as the total volume of the peak ( voxel value). The total volume of the peak (nm ³ ) was obtained by multiplying the total volume of the peak (voxel value) by the volume per 1 voxel (ie, 5 nm×5 nm×10 nm), and by dividing it into the resolution area (2000 nm×2000 nm) areas were divided to calculate the total volume (nm ³ ) of the peak per unit area of 1 nm ² . The results are as shown in Table 2.

(b) Shear strength Use the obtained roughened copper foil or copper foil with a carrier to make a laminate for evaluation. That is, on the surface of the inner substrate, the copper foil with a carrier or the roughened copper layer is laminated so as to be in contact with the roughened surface through a prepreg (manufactured by Mitsubishi Gas Chemical Co., Ltd., GHPL-830NSF, thickness 30 μm). The foil was bonded by thermocompression at a pressure of 4.0 MPa and a temperature of 220° C. for 90 minutes. Then, if it is copper foil with a carrier, a carrier is peeled off, and the laminated body for evaluation is obtained.

A dry film was attached to the above-mentioned laminated body for evaluation, and exposure and development were performed. After the layered body masked by the developed dry film was deposited by pattern plating to deposit a copper layer, the dry film was peeled off. Etch the copper part exposed by the sulfuric acid-hydrogen peroxide-based etchant, and prepare a sample for measuring shear strength with a height of 15 μm, a width of 14 μm, and a length of 150 μm. Using a bond strength tester (4000Plus Bond tester manufactured by Nordson DAGE), the shear strength when the sample for shear strength measurement was pushed down from the lateral direction was measured. At this time, the test type is set as a destruction test, and the measurement is carried out under the conditions of a test height of 5 μm, a falling speed of 0.05 mm/s, a test speed of 200 μm/s, a tool movement of 0.03 mm, and a failure identification point of 10%. The obtained shear strength was graded and evaluated according to the following criteria, and the evaluations A and B were judged to be acceptable. The results are as shown in Table 2. ＜Shear Strength Evaluation Standard＞ ‐Evaluation A: The shear strength is 21.3 gf/cm or more ‐Assessment B: The shear strength exceeds 19.9 gf/cm but falls short of 21.3 gf/cm ‐Evaluation C: The shear strength is 19.9 gf/cm or less

(c) Transmission characteristics Two prepregs (Panasonic Co., Ltd., MEGTRON6, actual thickness 68 μm) are stacked, and the roughened surface of the copper foil with the carrier or the roughened copper foil is abutted on both sides, and the temperature is 190 ℃ using a vacuum press machine. Under thermocompression bonding for 90 minutes. Then, if it is copper foil with a carrier, the carrier is peeled off and the copper foil laminated board is obtained. Copper plating was performed so that the copper thickness of this copper-clad laminated board became 18 μm, and a substrate for measurement of transmission characteristics on which a microstrip circuit was formed was obtained by a removal method.

For the obtained substrate for measurement of transmission characteristics, using a network analyzer (manufactured by Agilent, PNA-X N5245A), a pattern with a characteristic impedance of the circuit of 50 Ω was selected, and the transmission loss S21 (dB/cm) up to 50 GHz was measured. Calculate the average of the obtained transmission loss at 45-50 GHz, and evaluate the absolute value according to the following criteria. Furthermore, when the transfer characteristic evaluation was A or B, it was judged as pass. The results are as shown in Table 2. <Evaluation criteria for transmission characteristics> ‐Evaluation A: The absolute value of transmission loss is 0.455 dB/cm or less ‐Evaluation B: The absolute value of the transmission loss exceeds 0.455 dB/cm but falls below 0.465 dB/cm ‐Evaluation C: The absolute value of transmission loss is 0.465 dB/cm or more

[Table 2] Table 2 3D analysis parameters performance Sum of peak and valley heights (nm ³ ) Surface Voxel Ratio (-) The total volume of the peak per unit area of 1 nm ² (nm ³ ) Average height of peaks and valleys (nm) Shear strength (gf/cm) and its evaluation Absolute value of transmission loss (dB/cm) and its evaluation example 1 1.9×10 ⁸ 0.39 22.2 51 20.6 B 0.460 B Example 2 2.8×10 ⁸ 0.32 37.3 74 21.5 A 0.456 B Example 3 1.6×10 ⁸ 0.46 19.0 45 21.0 B 0.450 A Example 4* 3.6×10 ⁸ 0.21 58.6 94 23.9 A 0.465 C Example 5* 1.2×10 ⁸ 0.76 6.4 37 19.2 C 0.455 A * indicates a comparative example.

10: roughened copper foil 10a: roughened particles 11: insulating resin substrate 11a: base material 11b: lower circuit 12: prepreg 13: primer layer 14: via hole 15: electroless copper plating 16: dry film 17: Electroplated copper 17a: Wiring part 18: Wiring Ap: Volume of peak relative to reference plane Av: Volume of valley relative to reference plane B: Voxel Bs: Surface voxel H: Average height of peak and valley Hp: Relative Height of the peak on the datum plane Hv: height of the valley relative to the datum plane N: area P ₁ , P ₂ , P ₃ : peak R: datum plane S: cutting plane x, y, z: axis

Fig. 1(a)-(d) is a flowchart for explaining the steps of the MSAP method, and is a diagram showing the first half of the steps (steps (a)-(d)). Fig. 2(e)-(g) is a flowchart for explaining the steps of the MSAP method, and is a diagram showing some steps (steps (e)-(g)) in the second half. Fig. 3 is a schematic cross-sectional view illustrating a reference plane of a roughened surface of a roughened copper foil, and a sum of heights of peaks and valleys. Fig. 4 is a schematic cross-sectional view illustrating the reference plane of the roughened surface of the roughened copper foil and the average height of peaks and valleys. FIG. 5 is a diagram in which the peaks existing on the roughened surface in the roughened copper foil are hypothetically divided by voxels. Fig. 6 is a diagram showing a region where laser light does not enter when a roughened surface is measured with a laser microscope. Fig. 7 is a diagram showing the x-axis, y-axis and z-axis under 3D-SEM observation, and the cut surface S in relation to the roughened copper foil. Fig. 8 is a diagram showing the relationship between each axis and the roughened copper foil after rotating the x-axis, y-axis, and z-axis in 3D-SEM image analysis.

10: Coarse treatment of copper foil

Ap: The volume of the peak relative to the reference plane

Av: the volume of the valley relative to the datum

R: reference plane

Claims (11)

A roughened copper foil having a roughened surface on at least one side, the roughened surface having a plurality of peaks that are convex with respect to a reference plane and a plurality of valleys that are concave with respect to the reference plane, The height of the peak and valley calculated as the sum of the volume of the peak and the volume of the valley in the analysis area of 2000 nm×2000 nm when the image obtained by the aforementioned roughened surface is analyzed using FIB-SEM The sum is 1.4×10 ⁸ nm ³ to 3.5×10 ⁸ nm ³ , and the average height of the peak and valley calculated as the sum of the average height of the peak and the average height of the valley is 40 nm to 90 nm. The roughened copper foil according to claim 1, wherein the sum of the heights of the aforementioned peaks and valleys is not less than 2.0×10 ⁸ nm ³ and not more than 3.5×10 ⁸ nm ³ . The roughened copper foil according to claim 1 or 2, wherein the average height of the aforementioned peaks and valleys is not less than 40 nm and not more than 80 nm. The roughened copper foil according to claim 1 or 2, wherein when the image obtained by using FIB-SEM for the roughened surface is subjected to three-dimensional image analysis, the total volume of the aforementioned peaks per unit area of ¹ nm is 7.0 nm ³ or more and 50.0 nm ³ or less. The roughened copper foil according to claim 4, wherein the total volume of the aforementioned peaks per unit area of 1 nm ² is not less than 30.0 nm ³ and not more than 50.0 nm ³ . The roughened copper foil according to claim 1 or 2, wherein when performing three-dimensional image analysis on the image obtained by using FIB-SEM for the aforementioned roughened surface and dividing the aforementioned peak into multiple voxels, 2000 nm×2000 The ratio of the total volume of voxels constituting the surface of the aforementioned peak to the total volume of all voxels constituting the aforementioned peak within the analysis region of nm, that is, the surface voxel ratio, is not less than 0.25 and not more than 0.60. The roughened copper foil according to claim 6, wherein the surface voxel ratio is not less than 0.25 and not more than 0.35. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is further provided with an antirust treatment layer and/or a silane coupling agent layer. A copper foil with a carrier, comprising: a carrier; a peeling layer disposed on the carrier; and the roughened copper foil according to claim 1 or 2, which is disposed on the peeling layer with the aforementioned roughened surface as the outside . A copper foil laminate, which has the roughened copper foil according to claim 1 or 2. A printed wiring board having the roughened copper foil according to claim 1 or 2.

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