WO2023281777A1 - Surface-treated copper foil, copper-clad laminate plate, and printed wiring board - Google Patents

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

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Publication number
WO2023281777A1
WO2023281777A1 PCT/JP2022/001220 JP2022001220W WO2023281777A1 WO 2023281777 A1 WO2023281777 A1 WO 2023281777A1 JP 2022001220 W JP2022001220 W JP 2022001220W WO 2023281777 A1 WO2023281777 A1 WO 2023281777A1
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WIPO (PCT)
Prior art keywords
copper foil
treated
layer
treatment layer
conditions
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PCT/JP2022/001220
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French (fr)
Japanese (ja)
Inventor
佑樹 松岡
翔平 岩沢
郁浩 五刀
誓哉 中島
敦史 三木
Original Assignee
Ｊｘ金属株式会社
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Application filed by Ｊｘ金属株式会社 filed Critical Ｊｘ金属株式会社
Priority to JP2023533046A priority Critical patent/JPWO2023281777A1/ja
Priority to CN202280015842.7A priority patent/CN116867930A/en
Priority to KR1020237028671A priority patent/KR20230154812A/en
Publication of WO2023281777A1 publication Critical patent/WO2023281777A1/en

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/40—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling foils which present special problems, e.g. because of thinness
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D1/00—Electroforming
    • C25D1/04—Wires; Strips; Foils
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/38—Electroplating: Baths therefor from solutions of copper
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/10—Electroplating with more than one layer of the same or of different metals
    • C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/16—Electroplating with layers of varying thickness
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/60—Electroplating characterised by the structure or texture of the layers
    • C25D5/605—Surface topography of the layers, e.g. rough, dendritic or nodular layers
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/06—Wires; Strips; Foils
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling
    • C25F1/02—Pickling; Descaling
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/03—Use of materials for the substrate
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/09—Use of materials for the conductive, e.g. metallic pattern

Definitions

  • the present disclosure relates to surface-treated copper foils, copper-clad laminates, and printed wiring boards.
  • Copper-clad laminates are widely used in various applications such as flexible printed wiring boards.
  • This flexible printed wiring board is made by etching the copper foil of a copper-clad laminate to form a conductor pattern (also called a "wiring pattern"), and mounting electronic components on the conductor pattern by connecting them with solder. manufactured.
  • the causes of loss of signal power (transmission loss) in electronic circuits can be roughly divided into two.
  • the first is conductor loss, that is, loss due to copper foil
  • the second is dielectric loss, that is, loss due to resin substrate.
  • Conductor loss has a skin effect in a high frequency range, and current has the property of flowing on the surface of the conductor. Therefore, in order to reduce the conductor loss of high frequency signals, it is desirable to reduce the surface roughness of the copper foil.
  • transmission loss and “conductor loss” in this specification mainly mean “transmission loss of high-frequency signals” and “conductor loss of high-frequency signals”.
  • Patent Literature 1 proposes a method of providing a roughening treatment layer formed of roughening particles on a copper foil and forming a silane coupling treatment layer on the outermost layer.
  • the surface of the copper foil on which the surface treatment layer is formed generally has fine irregularities.
  • fine irregularities For example, in the case of rolled copper foil, oil pits formed by rolling oil during rolling are formed on the surface as fine irregularities.
  • polishing streaks formed on the rotating drum during polishing cause fine irregularities on the surface of the electrolytic copper foil on the rotating drum side deposited and formed on the rotating drum. If there is a minute unevenness on the copper foil surface, for example, when forming a roughening treatment layer, the current concentrates on the unevenness of the copper foil surface, and the roughening particles overgrow. In and around these areas, the current is not sufficiently supplied, making it difficult for the roughened particles to grow.
  • the anchoring effect of the roughened particles is reduced, and sufficient adhesiveness between the copper foil and the resin substrate may not be obtained.
  • resin substrates made from low-dielectric materials such as liquid crystal polymers and low-dielectric polyimides are more difficult to adhere to copper foils than conventional resin substrates. It is desired to develop a method to increase the
  • the silane coupling treatment layer has the effect of improving the adhesion between the copper foil and the resin base material, the effect of improving the adhesion may not be sufficient depending on the type.
  • an object of the present invention has been made to solve the above problems, and in one aspect, it is possible to improve the adhesiveness to resin substrates, particularly resin substrates suitable for high frequency applications.
  • An object of the present invention is to provide a surface-treated copper foil that is superior in quality.
  • an embodiment of the present invention provides a copper-clad laminate having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high-frequency applications, and a surface-treated copper foil. aim.
  • an object of the embodiments of the present invention is to provide a printed wiring board having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high frequency applications, and a circuit pattern. .
  • the present inventors have made intensive research on surface-treated copper foils to solve the above problems.
  • the copper foil surface is It was found that the overgrowth of the roughening particles formed on the convex portions of the copper foil can be suppressed and the roughening particles can be easily formed around the concave portions of the copper foil surface.
  • the present inventors analyzed the surface shape of the surface-treated copper foil thus obtained, and found that the rate of change in Sk of the surface-treated layer is closely related to the surface shape. and completed the embodiment of the present invention.
  • an embodiment of the present invention has a copper foil and a surface treatment layer formed on at least one surface of the copper foil,
  • the surface-treated layer relates to a surface-treated copper foil having a rate of change of Sk represented by the following formula (1) of 23.0 to 45.0%.
  • Change rate of Sk (P2-P1)/P2 ⁇ 100 (1)
  • P1 is Sk calculated by applying a ⁇ s filter with a cutoff value ⁇ s of 2 ⁇ m
  • P2 is Sk calculated without applying the ⁇ s filter.
  • the embodiments of the present invention relate to a copper-clad laminate comprising the surface-treated copper foil and a resin substrate adhered to the surface treatment layer of the surface-treated copper foil. Furthermore, in another aspect, the embodiment of the present invention relates to a printed wiring board including a circuit pattern formed by etching the surface-treated copper foil of the copper-clad laminate.
  • a surface-treated copper foil capable of enhancing adhesiveness to a resin substrate, particularly a resin substrate suitable for high frequency applications.
  • a copper-clad laminate having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high-frequency applications, and a surface-treated copper foil. be able to.
  • a printed wiring board having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high frequency applications, and a circuit pattern. .
  • FIG. 4 is a schematic diagram for explaining roughening particles and Sk that constitute the surface treatment layer.
  • 1 is a schematic enlarged cross-sectional view of a surface-treated copper foil having a roughened layer on one surface of the copper foil;
  • a surface-treated copper foil according to an embodiment of the present invention has a copper foil and a surface treatment layer formed on at least one surface of the copper foil.
  • the surface treatment layer may be formed only on one surface of the copper foil, or may be formed on both surfaces of the copper foil.
  • the types of surface treatment layers may be the same or different.
  • the surface profile of the surface treatment layer can be specified using surface texture parameters obtained by measuring the surface texture and analyzing the load curve calculated from the measured data in accordance with ISO 25178-2:2012.
  • the load area ratio is a ratio obtained by dividing a region corresponding to a cross section of a three-dimensional measurement object cut along a plane of a certain height by the area of the measurement visual field.
  • the object to be measured is assumed to be a copper foil, a surface-treated layer of a surface-treated copper foil, or the like.
  • the load curve is a curve representing the load area ratio at each height.
  • the height near 0% of the load area ratio represents the height of the highest portion of the object to be measured, and the height near 100% of the load area ratio represents the height of the lowest portion of the object to be measured.
  • FIG. 1 shows a typical load curve of the surface treatment layer.
  • the equivalent straight line is obtained in accordance with Section 5.2 of JIS B0681-2:2018. That is, first, the secant line of the load curve drawn from the load area ratio of 0% along the load curve with the difference in the load area ratio of 40% is moved from the load area ratio of 0% to 100%, and the secant line The point where the slope of Next, the straight line that minimizes the sum of squares of deviations in the vertical axis direction with respect to the central portion is called an equivalent straight line.
  • the core portion, protruding peak portion, and protruding valley portion of the object to be measured are distinguished. That is, of the object to be measured, the portion within the range of the height of the load area ratio of 0% to 100% on the equivalent straight line is the core portion, and the portion protruding upward from the core portion is the protruding peak portion. The portion recessed downward from the portion is the protruding valley portion.
  • the portion within the range of the height of the load area ratio of 0% to 100% on the equivalent straight line is the core portion
  • the portion protruding upward from the core portion is the protruding peak portion.
  • the portion recessed downward from the portion is the protruding valley portion.
  • Sk is the level difference of the core portion (the difference between the upper limit level and the lower limit level of the core portion)
  • Spk is the height of the protruding peak portion (average height of the protruding peak portion above the core portion)
  • Svk is Protruding valley depth (average depth of protruding valley below the core)
  • Smr1 is the load area ratio separating the protruding peak and the core
  • Smr2 is the load separating the protruding valley and the core
  • the protruding mountain portion is a particularly high region of the object to be measured.
  • a protruding trough is a particularly low region of the object to be measured.
  • the core portion is a region of the object to be measured other than the protruding peaks and protruding valleys, that is, the region having a height close to the average.
  • the protruding peak height Spk is the average value of the height of the protruding peaks, that is, the height of the area of the object to be measured that is large, and is the average value of the heights of the areas that are particularly large among the surface treatment layers. means.
  • the region having a particularly large height in the surface treatment layer is a region caused by overgrown grains among grains (especially, roughened grains).
  • the core portion has the average height of the measurement object, and can be said to be the average height of the surface treatment layer. Therefore, the level difference Sk of the core portion is one On the side, the particles with the largest height (especially, roughened particles) and the smallest particles (especially, roughened particles).
  • the core portion is the average height of the area of the surface treatment layer
  • Sk which is the level difference of the core portion
  • Sk is the average size of particles (especially roughened particles) adhesion It can be interpreted as a value that correlates with the amount.
  • Sk is the adhesion amount of average-sized particles constituting the surface treatment layer
  • Spk are found to be correlated with the height of the overgrown grains respectively.
  • roughened particles are used as examples of particles in the following description, it should be noted that the particles are not limited to roughened particles.
  • Measurement data for measuring the surface properties of the surface-treated copper foil according to the embodiment of the present invention can be obtained using a laser microscope such as a confocal laser microscope.
  • the measured data can be separated into waveforms having various periods and amplitudes.
  • the surface properties to be noticed from the measurement data are analyzed by synthesizing all the waveforms again. The inventors thought that the parameters could be calculated.
  • the present inventors found that surface texture parameters calculated by applying a ⁇ s filter with a cutoff value ⁇ s of 2 ⁇ m and surface texture parameters calculated without applying this ⁇ s filter By using a combination of rice field.
  • the ⁇ s filter is a profile filter that greatly attenuates the amplitude of waveforms with wavelengths smaller than the cutoff value ⁇ s.
  • the ⁇ s filter corresponds to the S filter in ISO 25178-2:2012. The amount by which the ⁇ s filter attenuates the amplitude depends on the wavelength of the waveform.
  • the amplitude is attenuated to 50% of its original value, and at waveforms with shorter wavelengths, the amplitude is attenuated more.
  • the cutoff value ⁇ s of 2 ⁇ m is a size positioned between the size of the roughening particles forming the surface treatment layer and the size of the oil pit. Since the measurement data obtained by setting the cutoff value ⁇ s to 2 ⁇ m is data derived from a waveform with a period shorter than the cutoff value ⁇ s, it is understood that the data derived from roughening particles are removed. can.
  • the difference between the surface texture parameter calculated without applying the ⁇ s filter with a cutoff value ⁇ s of 2 ⁇ m and the surface texture parameter calculated using this ⁇ s filter is the oil pit information. It can be said that it is the information of the removed surface treatment layer, that is, the information of the roughening particles constituting the surface treatment layer.
  • the present inventors analyzed various surface property parameters obtained from the load curve, and found that the rate of change of Sk represented by the following formula (1) in the surface treatment layer was It was found to be closely related to the adhesion amount of average-sized roughening particles forming the treated layer.
  • Change rate of Sk (P2-P1)/P2 ⁇ 100 (1)
  • P1 is Sk calculated by applying a ⁇ s filter with a cutoff value ⁇ s of 2 ⁇ m
  • P2 is Sk calculated without applying the ⁇ s filter.
  • FIG. 2 shows a schematic diagram for explaining the roughening particles and Sk that constitute the surface treatment layer.
  • the surface treatment layer includes average-sized roughening particles A and overgrown roughening particles B.
  • Sk is considered to correlate with the adherence amount of average-sized roughening particles A formed on the relatively smooth portion of the copper foil surface. Sk is not a little affected by macroscopic shapes such as oil pits, and in order to read the information of the surface treatment layer more accurately, it is necessary to remove the contribution of macroscopic shapes.
  • P1 can be interpreted as the value of Sk from which the information derived from the roughening particles has been removed, in other words, the value of Sk from which the information derived from the oil pit or the like remains.
  • Taking the difference between P2 and P1 means removing information derived from macroscopic shapes such as oil pits included in Sk. As a result, it is possible to accurately extract information correlated with the roughened particles A having an average size. It is considered that the average-sized roughened particles A formed on the relatively smooth portion of the copper foil surface have a great relationship with the adhesive strength between the resin substrate and the surface treatment layer. It is thought that overgrown (coarse) roughened particles B lead to roughening breakage, and excessively small roughened particles do not bite into the resin substrate in the first place.
  • the surface-treated copper foil according to the embodiment of the present invention having a rate of change in Sk of 23.0 to 45.0% exhibits sufficient adhesion to resin substrates.
  • the change rate of Sk is preferably 23.0 to 40.0%, more preferably 23.0 to 36.0%, from the viewpoint of stably obtaining this effect.
  • the surface treatment layer preferably has an Sku (kurtosis) of 2.50 to 4.50 calculated without applying the ⁇ s filter.
  • the surface-treated copper foil according to the embodiment of the present invention has unevenness on the surface, and the unevenness contributes to the improvement of adhesion between the copper foil and the resin substrate.
  • the Sku of the surface treatment layer serves as an index for evaluating the height distribution of the unevenness.
  • the Sku of the surface treatment layer being 2.50 to 4.50 means that the height distribution is a normal distribution or a distribution state close thereto.
  • the Sku of the surface treatment layer is less than 2.50, the height distribution means that the distribution is unbiased.
  • the Sku of the surface treatment layer is greater than 4.50, it means that the height distribution is uneven, that is, the surface of the surface treatment layer has a portion with a certain height that protrudes and occupies a large portion.
  • the height distribution of the surface treatment layer is a normal distribution or a distribution state close to it, for example, when a roughening treatment layer is formed on the surface of the copper foil, particles overgrown on the convex portions of the copper foil surface, that is, roughening particles Also, it means that there are few places where particles are not formed around the recesses (edges of the protrusions) on the surface of the copper foil. Therefore, when the Sku of the surface treatment layer is 2.50 to 4.50, the overgrowth of particles formed on the convex portions of the copper foil surface is suppressed, and the particles are also formed around the concave portions on the copper foil surface. It means the state of being formed.
  • a surface-treated copper foil with a large number of roughened particles and a surface-treated copper foil with portions where particles are not formed are not preferable from the viewpoint of adhesiveness to a resin substrate.
  • a surface-treated copper foil with a large number of roughened particles if a force is applied to peel off the surface-treated copper foil after bonding to the resin base material, the stress will concentrate on the roughened particles, making it easier to break. It is thought that the adhesive force to the material is reduced.
  • a surface-treated copper foil having a portion where particles are not formed cannot sufficiently ensure the anchoring effect of the particles, and the adhesive strength between the surface-treated copper foil and the resin substrate decreases.
  • the lower limit of Sku of the surface treatment layer is preferably 2.90, and the upper limit is preferably 4.10.
  • the Sku of the surface treatment layer can be specified by measuring the surface roughness and analyzing the contour curve calculated from the measurement data in accordance with ISO 25178-2:2012.
  • the surface treatment layer preferably has an Sq (root mean square height) of 0.20 to 0.60 ⁇ m calculated without applying the ⁇ s filter.
  • Sq is a parameter in the height direction defined in ISO 25178-2:2012, and represents the height variation of the protrusions on the surface of the surface treatment layer.
  • a large Sq of the surface treatment layer means that the height of the protrusions on the surface of the surface treatment layer varies greatly. If Sq is too large (variation in the height of the convex portion is too large), it may pose a problem from the viewpoint of quality control as an industrial product. Therefore, by setting the Sq of the surface treatment layer within the above range, it is possible to perform appropriate quality control while ensuring productivity by allowing some variation in the height of the protrusions.
  • the Sq of the surface treatment layer preferably has a lower limit of 0.26 ⁇ m, more preferably 0.30 ⁇ m, still more preferably 0.34 ⁇ m, and an upper limit of preferably 0. 0.53 ⁇ m, more preferably 0.48 ⁇ m, even more preferably 0.43 ⁇ m.
  • the Sq of the surface treatment layer can be specified by measuring the surface roughness and analyzing the contour curve calculated from the measurement data in accordance with ISO 25178-2:2012.
  • the surface treatment layer preferably has an Sa (arithmetic mean height) of 0.20 to 0.40 ⁇ m calculated without applying the ⁇ s filter.
  • Sa is a parameter in the height direction defined in ISO 25178-2:2012 and represents the average height difference from the average plane. If the Sa of the surface-treated layer is large, the surface of the surface-treated layer becomes rough, so that the anchor effect is likely to be exhibited when the surface-treated copper foil is adhered to a resin base material. On the other hand, if the Sa of the surface-treated layer is too large, when a circuit board is fabricated by processing a copper-clad laminate in which the surface-treated copper foil and the resin substrate are bonded, transmission loss will occur due to the skin effect of the surface-treated copper foil. becomes larger.
  • the lower limit of Sa in the surface treatment layer is preferably 0.23 ⁇ m, more preferably 0.24 ⁇ m, and the upper limit is preferably 0.35 ⁇ m.
  • the surface treatment layer has a Sa of 0.20 to 0.32 ⁇ m and an Sq of 0.26 to 0. 0.40 ⁇ m is preferred.
  • the Sa of the surface treatment layer can be specified by measuring the surface roughness and analyzing the contour curve calculated from the measurement data according to ISO 25178-2:2012.
  • the surface treatment layer preferably has an Ssk (skewness) of ⁇ 1.10 to 0.60 calculated without applying the ⁇ s filter.
  • Ssk is -1.10 to 0.60 means that, for example, when a roughening treatment layer is formed on the surface of the copper foil, roughening particles overgrown on the convex portions of the copper foil surface, that is, coarse roughness It means that there are few roughening particles and there are few places where roughening particles are not formed around the recesses (ends of the protrusions) on the copper foil surface. On the other hand, when it is less than -1.10, there are many places where the roughening particles are not formed around the recesses on the copper foil surface. Moreover, when Ssk is more than 0.60, a large number of overgrown roughened particles are present in the convex portions of the copper foil surface.
  • the upper limit of Ssk of the surface treatment layer is preferably 0.40, and the lower limit is preferably -0.80.
  • the Ssk of the surface treatment layer can be specified by measuring the surface roughness in accordance with ISO 25178-2:2012 and analyzing the contour curve calculated from the measurement data.
  • the type of surface treatment layer is not particularly limited, and various surface treatment layers known in the art can be used.
  • Examples of surface treatment layers include roughening treatment layers, heat resistance treatment layers, rust prevention treatment layers, chromate treatment layers, silane coupling treatment layers, and the like. These layers can be used singly or in combination of two or more.
  • the surface treatment layer preferably contains a roughening treatment layer from the viewpoint of adhesion to the resin substrate.
  • the surface treatment layer contains one or more layers selected from the group consisting of a heat-resistant treatment layer, an antirust treatment layer, a chromate treatment layer and a silane coupling treatment layer, these layers are roughening treatment layers. It is preferably provided above.
  • FIG. 3 shows a schematic enlarged cross-sectional view of a surface-treated copper foil having a roughened layer on one surface of the copper foil.
  • the roughening treatment layer formed on one surface of copper foil 10 includes roughening particles 20 and covering plating layer 30 covering at least part of roughening particles 20 .
  • the roughening particles 20 are formed not only near the center of the protrusions 11 on the surface of the copper foil 10 but also around the recesses 12 (ends of the protrusions 11).
  • overgrowth of the roughening particles 20 formed on the convex portions 11 of the copper foil 10 is suppressed by adding a small amount of a tungsten compound to the plating solution. Therefore, the roughened particles 20 do not overgrow into particles having a large particle size, and have a complicated shape that grows in each direction. It is considered that such a structure can be obtained by controlling the rate of change of Sk of the surface treatment layer within the above range.
  • the roughening particles 20 are not particularly limited, but may be a single element selected from the group consisting of copper, nickel, cobalt, phosphorus, tungsten, arsenic, molybdenum, chromium and zinc, or two or more of these elements. It can be formed from an alloy containing Among them, the roughening particles 20 are preferably made of copper or a copper alloy, particularly copper.
  • the covering plating layer 30 is not particularly limited, but can be made of copper, silver, gold, nickel, cobalt, zinc, or the like.
  • the roughened layer can be formed by electroplating.
  • the roughened particles 20 can be formed by electroplating using a plating solution containing a trace amount of tungsten compound.
  • the tungsten compound is not particularly limited, for example, sodium tungstate (Na 2 WO 4 ) can be used.
  • the content of the tungsten compound in the plating solution is preferably 1 ppm or more. With such a content, overgrowth of roughening particles 20 formed on convex portions 11 can be suppressed, and roughening particles 20 can be easily formed around concave portions 12 .
  • the upper limit of the content of the tungsten compound is not particularly limited, it is preferably 20 ppm from the viewpoint of suppressing an increase in electrical resistance.
  • Electroplating conditions for forming the roughened layer are not particularly limited and may be adjusted according to the electroplating apparatus used, but typical conditions are as follows. Each electroplating may be performed once or may be performed multiple times. (Conditions for forming roughening particles 20) Plating solution composition: 5-15 g/L Cu, 40-100 g/L sulfuric acid, 1-6 ppm sodium tungstate Plating solution temperature: 20-50°C Electroplating conditions: current density 30-90 A/dm 2 , time 0.1-8 seconds
  • Plating solution composition 10-30 g/L Cu, 70-130 g/L sulfuric acid Plating solution temperature: 30-60°C
  • Electroplating conditions current density 4.8-15 A/dm 2 , time 0.1-8 seconds
  • the heat-resistant layer and the rust-proof layer are not particularly limited, and can be formed from materials known in the art.
  • the heat-resistant treatment layer may also function as a rust-preventive treatment layer, a single layer having the functions of both the heat-resistant treatment layer and the rust-preventive treatment layer is formed as the heat-resistant treatment layer and the rust-preventive treatment layer. good too.
  • the heat-resistant layer and/or rust-proof layer nickel, zinc, tin, cobalt, molybdenum, copper, tungsten, phosphorus, arsenic, chromium, vanadium, titanium, aluminum, gold, silver, platinum group elements, iron, tantalum It can be a layer containing one or more elements selected from the group of (any form of metal, alloy, oxide, nitride, sulfide, etc.). Among them, the heat-resistant layer and/or the rust-proof layer is preferably a Ni—Zn layer.
  • the heat-resistant layer and the rust-proof layer can be formed by electroplating.
  • the conditions may be adjusted according to the electroplating apparatus to be used, and are not particularly limited, but the conditions for forming the heat-resistant layer (Ni—Zn layer) using a general electroplating apparatus are as follows. be. Electroplating may be performed once or multiple times. Plating solution composition: 1 to 30 g/L Ni, 1 to 30 g/L Zn Plating solution pH: 2-5 Plating solution temperature: 30-50°C Electroplating conditions: current density 0.1 to 10 A/dm 2 , time 0.1 to 5 seconds
  • the chromate treatment layer is not particularly limited, and can be formed from materials known in the technical field.
  • the term "chromate treatment layer” means a layer formed of a liquid containing chromic anhydride, chromic acid, dichromic acid, chromate, or dichromate.
  • the chromate treatment layer contains elements such as cobalt, iron, nickel, molybdenum, zinc, tantalum, copper, aluminum, phosphorus, tungsten, tin, arsenic, titanium, etc. (any metal, alloy, oxide, nitride, sulfide, etc.) morphology).
  • chromate-treated layer examples include a chromate-treated layer treated with an aqueous solution of chromic acid anhydride or potassium dichromate, a chromate-treated layer treated with a treatment liquid containing chromic anhydride or potassium dichromate and zinc, and the like.
  • the chromate treatment layer can be formed by known methods such as immersion chromate treatment and electrolytic chromate treatment. These conditions are not particularly limited, but, for example, the conditions for forming a general chromate treatment layer are as follows.
  • the chromate treatment may be performed once or multiple times.
  • Chromate liquid composition 1-10 g/L K 2 Cr 2 O 7 , 0.01-10 g/L Zn Chromate solution pH: 2-5
  • Chromate liquid temperature 30-55°C
  • Electrolytic conditions current density 0.1 to 10 A/dm 2 , time 0.1 to 5 seconds (for electrolytic chromate treatment)
  • silane coupling-treated layer is not particularly limited, and can be formed from materials known in the art.
  • silane coupling treated layer means a layer formed with a silane coupling agent.
  • the silane coupling agent is not particularly limited, and those known in the art can be used.
  • silane coupling agents include amino-based silane coupling agents, epoxy-based silane coupling agents, mercapto-based silane coupling agents, methacryloxy-based silane coupling agents, vinyl-based silane coupling agents, and imidazole-based silane coupling agents. , triazine-based silane coupling agents, and the like. Among these, amino-based silane coupling agents and epoxy-based silane coupling agents are preferred.
  • a representative method for forming a silane coupling-treated layer includes a method of forming a silane coupling-treated layer by applying a 1 to 3% by volume aqueous solution of the above-mentioned silane coupling agent and drying it.
  • the copper foil 10 is not particularly limited, and may be either an electrolytic copper foil or a rolled copper foil.
  • Electrodeposited copper foil is generally produced by electrolytically depositing copper from a copper sulfate plating bath onto a titanium or stainless steel drum. and an M surface (matte surface) formed on the opposite side of the .
  • the M side of the electrolytic copper foil generally has minute unevenness.
  • the S side of the electrolytic copper foil has fine irregularities because polishing streaks formed on the rotary drum during polishing are transferred to the S side.
  • the rolled copper foil has oil pits formed by the rolling oil during rolling, so that the rolled copper foil has minute irregularities on its surface.
  • the material of the copper foil 10 is not particularly limited.
  • High-purity copper such as alloy number C1020 or JIS H3510 alloy number C1011) can be used.
  • Copper alloys such as Sn-containing copper, Ag-containing copper, copper alloys containing Cr, Zr, Mg, etc., and Corson copper alloys containing Ni, Si, etc. can also be used.
  • the "copper foil 10" is a concept including a copper alloy foil.
  • the thickness of the copper foil 10 is not particularly limited. can.
  • the surface-treated copper foil having the configuration as described above can be produced according to a method known in the technical field.
  • the parameters such as the rate of change of Sk of the surface treatment layer can be controlled by adjusting the conditions for forming the surface treatment layer, particularly the conditions for forming the roughening treatment layer described above.
  • the surface-treated copper foil according to the embodiment of the present invention controls the rate of change of Sk of the surface treatment layer to 23.0 to 45.0%, it is a resin base material, especially a resin base material suitable for high frequency applications. can enhance the adhesion with.
  • a copper-clad laminate according to an embodiment of the present invention includes the surface-treated copper foil described above and a resin substrate adhered to the surface-treated layer of the surface-treated copper foil.
  • This copper-clad laminate can be produced by adhering a resin substrate to the surface-treated layer of the surface-treated copper foil.
  • the resin substrate is not particularly limited, and those known in the art can be used.
  • resin base materials include paper base phenol resin, paper base epoxy resin, synthetic fiber cloth base epoxy resin, glass cloth/paper composite base epoxy resin, glass cloth/glass nonwoven cloth composite base epoxy resin, glass Examples include cloth-based epoxy resins, polyester films, polyimide resins, liquid crystal polymers, and fluorine resins.
  • polyimide resin is preferable.
  • the method for bonding the surface-treated copper foil and the resin substrate is not particularly limited, and can be performed according to a method known in the art.
  • a surface-treated copper foil and a resin base material may be laminated and thermocompression bonded.
  • the copper-clad laminate manufactured as described above can be used for manufacturing a printed wiring board.
  • the copper-clad laminate according to the embodiment of the present invention uses the surface-treated copper foil described above, it is possible to improve the adhesiveness to resin substrates, particularly resin substrates suitable for high-frequency applications.
  • a printed wiring board according to an embodiment of the present invention includes a circuit pattern formed by etching the surface-treated copper foil of the copper-clad laminate.
  • This printed wiring board can be produced by etching the surface-treated copper foil of the copper-clad laminate to form a circuit pattern.
  • a method for forming a circuit pattern is not particularly limited, and known methods such as a subtractive method and a semi-additive method can be used. Among them, the subtractive method is preferable as the method of forming the circuit pattern.
  • a predetermined resist pattern is formed by applying a resist to the surface of the surface-treated copper foil of the copper clad laminate, exposing and developing the resist.
  • the circuit pattern is formed by removing the surface-treated copper foil from the portion where the resist pattern is not formed (unnecessary portion) by etching. Finally, the resist pattern on the surface-treated copper foil is removed.
  • Various conditions in this subtractive method are not particularly limited, and can be carried out according to conditions known in the technical field.
  • the printed wiring board according to the embodiment of the present invention uses the above copper clad laminate, it has excellent adhesion between the resin substrate, particularly the resin substrate suitable for high frequency applications, and the circuit pattern. .
  • Example 1 Prepare a rolled copper foil (HA-V2 foil manufactured by JX Metals Co., Ltd.) with a thickness of 12 ⁇ m, degreasing and pickling one side, roughening treatment layer as a surface treatment layer, heat treatment layer (Ni-Zn layer ), a chromate-treated layer and a silane coupling-treated layer were sequentially formed to obtain a surface-treated copper foil.
  • the conditions for forming each treated layer were as follows.
  • Plating solution composition 20 g/L Cu, 100 g/L sulfuric acid Plating solution temperature: 50°C
  • Chromate-treated layer ⁇ Conditions for forming electrolytic chromate-treated layer> Chromate liquid composition: 3 g/L K2Cr2O7 , 0.33 g/L Zn Chromate solution pH: 3.7 Chromate liquid temperature: 55°C Electrolysis conditions: current density 1.42 A/dm 2 , time 0.73 seconds Number of chromate treatments: 2 times
  • Silane Coupling Treated Layer A 1.2% by volume aqueous solution of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane was applied and dried to form a silane coupling treated layer.
  • Example 2 A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
  • Electroplating conditions current density 74.8 A/dm 2 , time 0.58 seconds ⁇ Conditions for forming cover plating layer>
  • Electroplating conditions current density 11.0 A/dm 2 , time 1.10 seconds ⁇ Conditions for Ni—Zn layer formation>
  • Electroplating conditions current density 0.68 A/dm 2 , time 0.56 seconds ⁇ Conditions for forming electrolytic chromate treatment layer>
  • Electrolysis conditions current density 1.90 A/dm 2 , time 0.56 seconds
  • Example 3 A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
  • Electroplating conditions current density 48.7 A/dm 2 , time 1.01 seconds
  • Electroplating conditions current density 8.2 A/dm 2 , time 1.44 seconds
  • Electroplating conditions current density 0.73 A/dm 2 , time 0.73 seconds
  • Electrolysis conditions current density 1.51 A/dm 2 , time 0.73 seconds
  • Example 4 A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed. ⁇ Conditions for Forming Roughened Particles> Plating solution composition: 11 g/L Cu, 50 g/L sulfuric acid, 3 ppm tungsten (from sodium tungstate dihydrate) Electroplating conditions: current density 38.8 A/dm 2 , time 1.27 seconds ⁇ Conditions for forming cover plating layer> Electroplating conditions: current density 8.2 A/dm 2 , time 1.44 seconds ⁇ Conditions for Ni—Zn layer formation> Electroplating conditions: current density 0.59 A/dm 2 , time 0.73 seconds
  • Example 5 A rolled copper foil (HG foil manufactured by JX Metals Co., Ltd.) with a thickness of 12 ⁇ m is prepared, one side is degreased and pickled, and then a roughened layer and a heat-resistant layer (Ni—Zn layer) are formed as surface treatment layers.
  • a surface-treated copper foil was obtained by sequentially forming a chromate-treated layer and a silane coupling-treated layer. The conditions for forming each treated layer were as follows.
  • Plating solution composition 20 g/L Cu, 100 g/L sulfuric acid Plating solution temperature: 50°C
  • Chromate-treated layer ⁇ Conditions for forming electrolytic chromate-treated layer> Chromate liquid composition: 3 g/L K2Cr2O7 , 0.33 g/L Zn Chromate solution pH: 3.65 Chromate liquid temperature: 55°C Electrolysis conditions: current density 1.91 A/dm 2 , time 0.59 seconds Number of chromate treatments: 2 times
  • Silane Coupling Treated Layer A 1.2% by volume aqueous solution of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane was applied and dried to form a silane coupling treated layer.
  • Example 1 The rolled copper foil (copper foil without surface treatment) used in Example 1 was used for comparison.
  • Example 2 A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
  • Plating solution composition 11 g/L of Cu, 50 g/L of sulfuric acid
  • Electroplating conditions current density of 38.8 A/dm 2 , time of 1.27 seconds
  • Electroplating conditions current density 8.2 A/dm 2 , time 1.44 seconds
  • Electroplating conditions current density 0.59 A/dm 2 , time 0.73 seconds
  • Electrolysis conditions current density 1.42 A/dm 2 , time 0.73 seconds
  • the surface-treated copper foils or copper foils obtained in the above examples and comparative examples were evaluated for the following characteristics.
  • ⁇ Sk, Sku, Sq, Sa and Ssk> In accordance with ISO 25178-2:2012, measurement (image photography) was performed using a laser microscope (LEXT OLS4000) manufactured by Olympus Corporation. The captured images were analyzed using analysis software for a laser microscope (LEXT OLS4100) manufactured by Olympus Corporation. The average value of the values measured and analyzed at any five locations was used as the result. The temperature during the measurement was 23 to 25°C. Main setting conditions for the laser microscope and analysis software are as follows.
  • Objective lens MPLAPON50XLEXT (magnification: 50x, numerical aperture: 0.95, liquid immersion type: air, mechanical barrel length: ⁇ , cover glass thickness: 0, field number: FN18)
  • Optical zoom magnification 1x
  • Scanning mode: XYZ high precision (height resolution: 60 nm, number of pixels of captured data: 1024 x 1024)
  • Captured image size [Number of pixels]: Horizontal 257 ⁇ m ⁇ Vertical 258 ⁇ m [1024 ⁇ 1024] (Since it is measured in the horizontal direction, it corresponds to 257 ⁇ m as an evaluation length)
  • Optical system d/8°, integrating sphere size: 63.5 mm, observation light source: D65 Measurement method: Reflection Illumination diameter: 25.4mm Measurement diameter: 20.0mm Measurement wavelength/interval: 400 to 700 nm/10 nm Light source: pulsed xenon lamp, 1 emission/measurement Traceability standard: National Institute of Standards and Technology (NIST) compliant calibration based on CIE 44 and ASTM E259 Standard observer: 10° In addition, the following object colors were used for the white tiles used as the measurement standard. When measured at D65/10°, the values in the CIE XYZ color system are X: 81.90, Y: 87.02, Z: 93.76
  • ⁇ Peel strength> After bonding the surface-treated copper foil to the polyimide resin substrate, a circuit with a width of 3 mm was formed in the MD direction (longitudinal direction of the rolled copper foil). Formation of the circuit was carried out according to the usual method. Next, the circuit (surface-treated copper foil) is peeled off from the surface of the resin base material at a speed of 50 mm/min in a 90° direction, that is, vertically upward with respect to the surface of the resin base material. The thickness (MD90° peel strength) was measured according to JIS C6471:1995. The measurement was performed three times, and the average value was taken as the result of the peel strength.
  • the peel strength is 0.50 kgf/cm or more, it can be said that the adhesion between the circuit (surface-treated copper foil) and the resin substrate is good. This evaluation was not performed for the copper foil of Comparative Example 1 because it could not be attached to the polyimide resin substrate.
  • Table 1 shows the results of the above characteristic evaluation.
  • the embodiments of the present invention it is possible to increase the adhesion to resin substrates, particularly resin substrates suitable for high frequency applications.
  • a surface-treated copper foil can be provided.

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Abstract

Provided is a surface-treated copper foil including a copper foil and a surface-treated layer formed on at least one surface of the copper foil. The surface-treated layer has an Sk rate of change, represented by formula (1) below, of 23.0-45.0%.　Formula (1): Sk rate of change = (P2-P1)/P2×100　In the formula, P1 is Sk calculated by applying a λs filter having a cutoff value λs of 2 µm, and P2 is Sk calculated without applying the λs filter.

Description

表面処理銅箔、銅張積層板及びプリント配線板Surface treated copper foil, copper clad laminate and printed wiring board
　本開示は、表面処理銅箔、銅張積層板及びプリント配線板に関する。 The present disclosure relates to surface-treated copper foils, copper-clad laminates, and printed wiring boards.
　銅張積層板は、フレキシブルプリント配線板などの各種用途において広く用いられている。このフレキシブルプリント配線板は、銅張積層板の銅箔をエッチングして導体パターン（「配線パターン」とも称される）を形成し、導体パターン上に電子部品を半田で接続して実装することによって製造される。 Copper-clad laminates are widely used in various applications such as flexible printed wiring boards. This flexible printed wiring board is made by etching the copper foil of a copper-clad laminate to form a conductor pattern (also called a "wiring pattern"), and mounting electronic components on the conductor pattern by connecting them with solder. manufactured.
　近年、パソコン、モバイル端末などの電子機器では、通信の高速化及び大容量化に伴い、電気信号の高周波化が進んでおり、これに対応可能なフレキシブルプリント配線板が求められている。特に、電気信号の周波数は、高周波になるほど信号電力の損失（減衰）が大きくなり、データが読み取れなくなり易いため、信号電力の損失を低減することが求められている。 In recent years, in electronic devices such as personal computers and mobile terminals, the frequency of electrical signals has increased as the speed and capacity of communication have increased, and there is a demand for flexible printed wiring boards that can handle this. In particular, the higher the frequency of an electrical signal, the greater the loss (attenuation) of signal power, making it more likely that data cannot be read. Therefore, it is desired to reduce the loss of signal power.
　電子回路における信号電力の損失（伝送損失）が起こる原因は大きく二つに分けることができる。その一は、導体損失、すなわち銅箔による損失であり、その二は、誘電体損失、すなわち樹脂基材による損失である。
　導体損失は、高周波域では表皮効果があり、電流は導体の表面を流れるという特性を有するため、銅箔表面が粗いと複雑な経路を辿って、電流が流れることになる。したがって、高周波信号の導体損失を少なくするためには、銅箔の表面粗さを小さくすることが望ましい。以下、本明細書において、単に「伝送損失」及び「導体損失」と記載した場合は、「高周波信号の伝送損失」及び「高周波信号の導体損失」を主に意味する。 The causes of loss of signal power (transmission loss) in electronic circuits can be roughly divided into two. The first is conductor loss, that is, loss due to copper foil, and the second is dielectric loss, that is, loss due to resin substrate.
Conductor loss has a skin effect in a high frequency range, and current has the property of flowing on the surface of the conductor. Therefore, in order to reduce the conductor loss of high frequency signals, it is desirable to reduce the surface roughness of the copper foil. Hereinafter, the terms "transmission loss" and "conductor loss" in this specification mainly mean "transmission loss of high-frequency signals" and "conductor loss of high-frequency signals".
　他方、誘電体損失は、樹脂基材の種類に依存するため、高周波信号が流れる回路基板においては、低誘電材料（例えば、液晶ポリマー、低誘電ポリイミド）から形成された樹脂基材を用いることが望ましい。また、誘電体損失は、銅箔と樹脂基材との間を接着する接着剤によっても影響を受けるため、銅箔と樹脂基材との間は接着剤を用いずに接着することが望ましい。
　そこで、銅箔と樹脂基材との間を接着剤の使用なしに接着するために、銅箔の少なくとも一方の面に表面処理層を形成することが提案されている。例えば、特許文献１には、銅箔上に粗化粒子から形成される粗化処理層を設けるとともに、最表層にシランカップリング処理層を形成する方法が提案されている。 On the other hand, since the dielectric loss depends on the type of resin base material, it is possible to use a resin base material made of a low dielectric material (eg, liquid crystal polymer, low dielectric polyimide) in a circuit board through which high frequency signals flow. desirable. In addition, since the dielectric loss is also affected by the adhesive that bonds the copper foil and the resin substrate together, it is desirable to bond the copper foil and the resin substrate without using an adhesive.
Therefore, it has been proposed to form a surface treatment layer on at least one surface of the copper foil in order to bond the copper foil and the resin substrate without using an adhesive. For example, Patent Literature 1 proposes a method of providing a roughening treatment layer formed of roughening particles on a copper foil and forming a silane coupling treatment layer on the outermost layer.
特開２０１２－１１２００９号公報Japanese Unexamined Patent Application Publication No. 2012-112009
　表面処理層が形成される銅箔の表面には、一般的に微小な凹凸部が存在する。例えば、圧延銅箔の場合、圧延時に圧延油によって形成されるオイルピットが微小な凹凸部として表面に形成される。また、電解銅箔の場合、研磨時に形成された回転ドラムの研磨スジが、回転ドラム上に析出形成される電解銅箔の回転ドラム側表面の微小な凹凸部の原因となる。
　銅箔表面に微小な凹凸部が存在すると、例えば、粗化処理層を形成する際に、銅箔表面の凸部では電流が集中して粗化粒子が過成長する一方、銅箔表面の凹部及びその周辺では電流が十分に供給されず、粗化粒子が成長し難くなる。その結果、銅箔表面の凸部に粗大な粗化粒子が形成される一方、銅箔表面の凹部及びその周辺は粗化粒子が過小になる状態、特に、オイルピットの端部付近は粗化粒子の付着が不十分な状態、すなわち、銅箔表面の粗化粒子が均一に形成されていない状態になる。粗大な粗化粒子が多い表面処理銅箔では、樹脂基材との接合後、表面処理銅箔を剥離させる力を付与すると、粗大な粗化粒子に応力が集中して折れ易くなる結果、樹脂基材に対する接着力が低下することがある。また、粗化粒子の大きさが不十分な表面処理銅箔では、粗化粒子によるアンカー効果が低下してしまい、銅箔と樹脂基材との接着性が十分に得られないことがある。
　特に、液晶ポリマー、低誘電ポリイミドなどの低誘電材料から形成された樹脂基材は、従来の樹脂基材よりも銅箔と接着し難いため、銅箔と樹脂基材との間の接着性を高める手法の開発が望まれている。
　また、シランカップリング処理層は、銅箔と樹脂基材との間の接着性を向上させる効果を有するものの、その種類によっては、接着性の向上効果が十分ではないこともある。 The surface of the copper foil on which the surface treatment layer is formed generally has fine irregularities. For example, in the case of rolled copper foil, oil pits formed by rolling oil during rolling are formed on the surface as fine irregularities. In the case of electrolytic copper foil, polishing streaks formed on the rotating drum during polishing cause fine irregularities on the surface of the electrolytic copper foil on the rotating drum side deposited and formed on the rotating drum.
If there is a minute unevenness on the copper foil surface, for example, when forming a roughening treatment layer, the current concentrates on the unevenness of the copper foil surface, and the roughening particles overgrow. In and around these areas, the current is not sufficiently supplied, making it difficult for the roughened particles to grow. As a result, while coarse roughening particles are formed in the convex portions of the copper foil surface, the roughening particles are too small in the concave portions of the copper foil surface and their surroundings, especially near the edge of the oil pit. Insufficient adhesion of particles, that is, roughened particles on the copper foil surface are not uniformly formed. In the surface-treated copper foil, which has a large number of coarse roughened particles, when a force is applied to peel off the surface-treated copper foil after bonding to the resin base material, stress concentrates on the coarse roughened particles, making it easier to break. Adhesion to substrates may be reduced. In addition, in a surface-treated copper foil with roughened particles having an insufficient size, the anchoring effect of the roughened particles is reduced, and sufficient adhesiveness between the copper foil and the resin substrate may not be obtained.
In particular, resin substrates made from low-dielectric materials such as liquid crystal polymers and low-dielectric polyimides are more difficult to adhere to copper foils than conventional resin substrates. It is desired to develop a method to increase the
In addition, although the silane coupling treatment layer has the effect of improving the adhesion between the copper foil and the resin base material, the effect of improving the adhesion may not be sufficient depending on the type.
　本発明の実施形態は、上記のような問題を解決するためになされたものであり、一つの側面において、樹脂基材、特に高周波用途に好適な樹脂基材との接着性を高めることが可能な表面処理銅箔を提供することを目的とする。
　また、本発明の実施形態は、別の側面において、樹脂基材、特に高周波用途に好適な樹脂基材と表面処理銅箔との間の接着性に優れた銅張積層板を提供することを目的とする。
　さらに、本発明の実施形態は、別の側面において、樹脂基材、特に高周波用途に好適な樹脂基材と回路パターンとの間の接着性に優れたプリント配線板を提供することを目的とする。 The embodiments of the present invention have been made to solve the above problems, and in one aspect, it is possible to improve the adhesiveness to resin substrates, particularly resin substrates suitable for high frequency applications. An object of the present invention is to provide a surface-treated copper foil that is superior in quality.
In another aspect, an embodiment of the present invention provides a copper-clad laminate having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high-frequency applications, and a surface-treated copper foil. aim.
Furthermore, in another aspect, an object of the embodiments of the present invention is to provide a printed wiring board having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high frequency applications, and a circuit pattern. .
　本発明者らは、上記の問題を解決すべく表面処理銅箔について鋭意研究を行った結果、粗化処理層の形成に用いられるめっき液に微量のタングステン化合物を添加することにより、銅箔表面の凸部に形成される粗化粒子の過成長を抑制するとともに、銅箔表面の凹部周辺に粗化粒子を形成させ易くし得るという知見を得た。そして、本発明者らは、このようにして得られた表面処理銅箔の表面形状について分析を行ったところ、表面処理層のＳｋの変化率が、この表面形状と密接に関係していることを見出し、本発明の実施形態を完成するに至った。 The present inventors have made intensive research on surface-treated copper foils to solve the above problems. As a result, the copper foil surface is It was found that the overgrowth of the roughening particles formed on the convex portions of the copper foil can be suppressed and the roughening particles can be easily formed around the concave portions of the copper foil surface. The present inventors analyzed the surface shape of the surface-treated copper foil thus obtained, and found that the rate of change in Sk of the surface-treated layer is closely related to the surface shape. and completed the embodiment of the present invention.
　すなわち、本発明の実施形態は、一つの側面において、銅箔と、前記銅箔の少なくとも一方の面に形成された表面処理層とを有し、
　前記表面処理層は、下記式（１）で表されるＳｋの変化率が２３．０～４５．０％である表面処理銅箔に関する。
　Ｓｋの変化率＝（Ｐ２－Ｐ１）／Ｐ２×１００　・・・（１）
　式中、Ｐ１は、カットオフ値λｓが２μｍのλｓフィルタを適用して算出されるＳｋであり、Ｐ２は、前記λｓフィルタを適用せずに算出されるＳｋである。 That is, in one aspect, an embodiment of the present invention has a copper foil and a surface treatment layer formed on at least one surface of the copper foil,
The surface-treated layer relates to a surface-treated copper foil having a rate of change of Sk represented by the following formula (1) of 23.0 to 45.0%.
Change rate of Sk=(P2-P1)/P2×100 (1)
In the formula, P1 is Sk calculated by applying a λs filter with a cutoff value λs of 2 μm, and P2 is Sk calculated without applying the λs filter.
　また、本発明の実施形態は、別の側面において、前記表面処理銅箔と、前記表面処理銅箔の前記表面処理層に接着された樹脂基材とを備える銅張積層板に関する。
　さらに、本発明の実施形態は、別の側面において、前記銅張積層板の前記表面処理銅箔をエッチングして形成された回路パターンを備えるプリント配線板に関する。 In another aspect, the embodiments of the present invention relate to a copper-clad laminate comprising the surface-treated copper foil and a resin substrate adhered to the surface treatment layer of the surface-treated copper foil.
Furthermore, in another aspect, the embodiment of the present invention relates to a printed wiring board including a circuit pattern formed by etching the surface-treated copper foil of the copper-clad laminate.
　本発明の実施形態によれば、一つの側面において、樹脂基材、特に高周波用途に好適な樹脂基材との接着性を高めることが可能な表面処理銅箔を提供することができる。
　また、本発明の実施形態によれば、別の側面において、樹脂基材、特に高周波用途に好適な樹脂基材と表面処理銅箔との間の接着性に優れた銅張積層板を提供することができる。
　さらに、本発明の実施形態によれば、別の側面において、樹脂基材、特に高周波用途に好適な樹脂基材と回路パターンとの間の接着性に優れたプリント配線板を提供することができる。 According to an embodiment of the present invention, in one aspect, it is possible to provide a surface-treated copper foil capable of enhancing adhesiveness to a resin substrate, particularly a resin substrate suitable for high frequency applications.
Further, according to an embodiment of the present invention, in another aspect, there is provided a copper-clad laminate having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high-frequency applications, and a surface-treated copper foil. be able to.
Furthermore, according to the embodiment of the present invention, in another aspect, it is possible to provide a printed wiring board having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high frequency applications, and a circuit pattern. .
表面処理層の典型的な負荷曲線である。It is a typical load curve of a surface treatment layer. 表面処理層を構成する粗化粒子及びＳｋを説明するための模式的な概略図である。FIG. 4 is a schematic diagram for explaining roughening particles and Sk that constitute the surface treatment layer. 銅箔の一方の面に粗化処理層を有する表面処理銅箔の模式的な拡大断面図である。1 is a schematic enlarged cross-sectional view of a surface-treated copper foil having a roughened layer on one surface of the copper foil; FIG.
　以下、本発明の好適な実施形態について具体的に説明するが、本発明はこれらに限定されて解釈されるべきものではなく、本発明の要旨を逸脱しない限りにおいて、当業者の知識に基づいて、種々の変更、改良などを行うことができる。以下の実施形態に開示されている複数の構成要素は、適宜な組み合わせにより、種々の発明を形成できる。例えば、以下の実施形態に示される全構成要素からいくつかの構成要素を削除してもよいし、異なる実施形態の構成要素を適宜組み合わせてもよい。 Hereinafter, preferred embodiments of the present invention will be specifically described, but the present invention should not be construed as being limited to these, and as long as it does not depart from the gist of the present invention, , various modifications, improvements, etc. may be made. A plurality of constituent elements disclosed in the following embodiments can be combined appropriately to form various inventions. For example, some constituent elements may be deleted from all the constituent elements shown in the following embodiments, or constituent elements of different embodiments may be combined as appropriate.
　本発明の実施形態に係る表面処理銅箔は、銅箔と、銅箔の少なくとも一方の面に形成された表面処理層とを有する。
　表面処理層は、銅箔の一方の面のみに形成されていてもよいし、銅箔の両方の面に形成されていてもよい。銅箔の両方の面に表面処理層が形成される場合、表面処理層の種類は同一であっても異なっていてもよい。 A surface-treated copper foil according to an embodiment of the present invention has a copper foil and a surface treatment layer formed on at least one surface of the copper foil.
The surface treatment layer may be formed only on one surface of the copper foil, or may be formed on both surfaces of the copper foil. When surface treatment layers are formed on both surfaces of the copper foil, the types of surface treatment layers may be the same or different.
　表面処理層の表面形状は、ＩＳＯ　２５１７８－２：２０１２に準拠し、表面性状を測定し、測定データから算出した負荷曲線を解析することによって得られる表面性状パラメータを用いて特定することができる。
　負荷曲線の説明をするにあたり、まず、負荷面積率について説明する。
　負荷面積率とは、立体的な測定対象物を、ある高さの面で切断した場合の測定対象物の断面に相当する領域を測定視野の面積で除して求められる割合のことである。なお、本開示において、測定対象物としては、銅箔や表面処理銅箔の表面処理層などを想定している。負荷曲線は、各高さにおける負荷面積率を表した曲線である。負荷面積率０％付近は測定対象物の最も高い部分の高さを表し、負荷面積率１００％付近の高さは測定対象物の最も低い部分の高さを表す。 The surface profile of the surface treatment layer can be specified using surface texture parameters obtained by measuring the surface texture and analyzing the load curve calculated from the measured data in accordance with ISO 25178-2:2012.
Before explaining the load curve, the load area ratio will be explained first.
The load area ratio is a ratio obtained by dividing a region corresponding to a cross section of a three-dimensional measurement object cut along a plane of a certain height by the area of the measurement visual field. In the present disclosure, the object to be measured is assumed to be a copper foil, a surface-treated layer of a surface-treated copper foil, or the like. The load curve is a curve representing the load area ratio at each height. The height near 0% of the load area ratio represents the height of the highest portion of the object to be measured, and the height near 100% of the load area ratio represents the height of the lowest portion of the object to be measured.
　次に、表面処理層の典型的な負荷曲線を図１に示す。負荷曲線及び負荷曲線から導き出される等価直線を活用して、表面処理層の突出谷部、コア部及び突出山部の大きさを表現することができる。
　等価直線はＪＩＳ　Ｂ０６８１－２：２０１８の５．２項に準拠して求める。すなわち、まず、負荷面積率０％から負荷曲線に沿って負荷面積率の差を４０％にして引いた負荷曲線の割線を、負荷面積率０％から１００％に向かって移動させていき、割線の傾斜が最も緩くなる位置を負荷曲線の中央部分とする。次に、この中央部分に対して、縦軸方向の偏差の二乗和が最小になる直線を等価直線という。このようにして求めた等価直線及び負荷曲線を用い、測定対象物のコア部、突出山部及び突出谷部を区別する。すなわち、測定対象物のうち、等価直線上の負荷面積率０％から１００％の高さの範囲に入る部分がコア部であり、コア部から上に突出した部分が突出山部であり、コア部から下に窪んだ部分が突出谷部である。
　図１において、Ｓｋはコア部のレベル差（コア部の上限レベルと下限レベルとの差）、Ｓｐｋは突出山部高さ（コア部の上にある突出山部の平均高さ）、Ｓｖｋは突出谷部深さ（コア部の下にある突出谷部の平均深さ）、Ｓｍｒ１は突出山部とコア部とを分離する負荷面積率、Ｓｍｒ２は突出谷部とコア部とを分離する負荷面積率をそれぞれ意味する。
　なお、突出山部とは、測定対象物の中でも特に高い領域のことである。突出谷部とは、測定対象物の中でも特に低い領域のことである。コア部とは、測定対象物のうち、突出山部と突出谷部以外の領域、すなわち、平均に近い高さの領域である。 Next, FIG. 1 shows a typical load curve of the surface treatment layer. Utilizing the load curve and the equivalent straight line derived from the load curve, the sizes of the protruding troughs, cores and protruding peaks of the surface treatment layer can be expressed.
The equivalent straight line is obtained in accordance with Section 5.2 of JIS B0681-2:2018. That is, first, the secant line of the load curve drawn from the load area ratio of 0% along the load curve with the difference in the load area ratio of 40% is moved from the load area ratio of 0% to 100%, and the secant line The point where the slope of Next, the straight line that minimizes the sum of squares of deviations in the vertical axis direction with respect to the central portion is called an equivalent straight line. Using the equivalent straight line and load curve obtained in this manner, the core portion, protruding peak portion, and protruding valley portion of the object to be measured are distinguished. That is, of the object to be measured, the portion within the range of the height of the load area ratio of 0% to 100% on the equivalent straight line is the core portion, and the portion protruding upward from the core portion is the protruding peak portion. The portion recessed downward from the portion is the protruding valley portion.
In FIG. 1, Sk is the level difference of the core portion (the difference between the upper limit level and the lower limit level of the core portion), Spk is the height of the protruding peak portion (average height of the protruding peak portion above the core portion), and Svk is Protruding valley depth (average depth of protruding valley below the core), Smr1 is the load area ratio separating the protruding peak and the core, Smr2 is the load separating the protruding valley and the core Each means an area ratio.
It should be noted that the protruding mountain portion is a particularly high region of the object to be measured. A protruding trough is a particularly low region of the object to be measured. The core portion is a region of the object to be measured other than the protruding peaks and protruding valleys, that is, the region having a height close to the average.
　突出山部高さＳｐｋは、突出山部、すなわち、測定対象物の高さが大きい領域の高さの平均値であり、表面処理層の中でも高さが特に大きい領域の高さの平均値を意味する。ここで、表面処理層の中でも高さが特に大きい領域は、粒子（特に、粗化粒子）の中でも過成長した粒子に起因する領域であると解釈できる。
　コア部は、測定対象物の高さが平均的な領域の高さであり、表面処理層の平均的な高さの領域であるといえるため、コア部のレベル差であるＳｋは、一つの側面では、表面処理層を構成する平均的な大きさの粒子（特に、粗化粒子）の中での最も大きい高さの粒子（特に、粗化粒子）と最も小さい高さの粒子（特に、粗化粒子）との差ということができる。また、コア部が表面処理層の平均的な領域の高さであるという側面に着目すると、コア部のレベル差であるＳｋは、平均的な大きさの粒子（特に、粗化粒子）の付着量と相関がある値であると解釈できる。
　小括すると、本発明者らは上記のように分析した結果、本発明の実施形態に係る表面処理銅箔において、Ｓｋは表面処理層を構成する平均的な大きさの粒子の付着量、Ｓｐｋは過成長した粒子の高さにそれぞれ相関するという知見を得た。なお、以下では、粒子として粗化粒子の場合を例にして説明することがあるが、粒子は粗化粒子に限定されないことに留意すべきである。 The protruding peak height Spk is the average value of the height of the protruding peaks, that is, the height of the area of the object to be measured that is large, and is the average value of the heights of the areas that are particularly large among the surface treatment layers. means. Here, it can be interpreted that the region having a particularly large height in the surface treatment layer is a region caused by overgrown grains among grains (especially, roughened grains).
The core portion has the average height of the measurement object, and can be said to be the average height of the surface treatment layer. Therefore, the level difference Sk of the core portion is one On the side, the particles with the largest height (especially, roughened particles) and the smallest particles (especially, roughened particles). In addition, focusing on the aspect that the core portion is the average height of the area of the surface treatment layer, Sk, which is the level difference of the core portion, is the average size of particles (especially roughened particles) adhesion It can be interpreted as a value that correlates with the amount.
In summary, as a result of the above analysis by the present inventors, in the surface-treated copper foil according to the embodiment of the present invention, Sk is the adhesion amount of average-sized particles constituting the surface treatment layer, Spk are found to be correlated with the height of the overgrown grains respectively. It should be noted that although roughened particles are used as examples of particles in the following description, it should be noted that the particles are not limited to roughened particles.
　本発明の実施形態に係る表面処理銅箔の表面性状を測定するための測定データは、例えば共焦点レーザー顕微鏡などのレーザー顕微鏡を用いて取得できる。ここで、当該測定データにフーリエ変換を施すことで、測定データを様々な周期及び振幅を有する波形に分離することができる。分離後の各波形に対し、特定範囲の周波数の波形の振幅を減衰させるフィルタを適用した後、再度全ての波形を合成して得られるデータを解析することを通じ、測定データから着目すべき表面性状パラメータを算出することができる、と本発明者らは考えた。 Measurement data for measuring the surface properties of the surface-treated copper foil according to the embodiment of the present invention can be obtained using a laser microscope such as a confocal laser microscope. Here, by subjecting the measured data to Fourier transform, the measured data can be separated into waveforms having various periods and amplitudes. After applying a filter that attenuates the amplitude of the waveform in a specific range to each waveform after separation, the surface properties to be noticed from the measurement data are analyzed by synthesizing all the waveforms again. The inventors thought that the parameters could be calculated.
　表面粗さの測定データの解析において、本発明者らは、カットオフ値λｓが２μｍのλｓフィルタを適用して算出される表面性状パラメータ及びこのλｓフィルタを適用せずに算出される表面性状パラメータを組み合わせて用いることにより、本発明の実施形態に係る表面処理層の特徴的な表面形状（特に、表面処理層を構成する粗化粒子の付着状態）の詳細な情報が得られるという知見を得た。
　ここで、λｓフィルタは、カットオフ値λｓよりも小さい波長の波形の振幅を大きく減衰させる輪郭曲線フィルタである。λｓフィルタはＩＳＯ　２５１７８－２：２０１２におけるＳフィルタに相当する。λｓフィルタが振幅を減衰させる大きさは、波形の波長によって異なる。カットオフ値λｓの波長では、振幅を元の値の５０％に減衰させ、それより波長が小さい波形では、より大きく振幅を減衰させる。
　２μｍというカットオフ値λｓは、表面処理層を構成する粗化粒子のサイズと、オイルピットのサイズとの間に位置する大きさである。カットオフ値λｓを２μｍに設定することにより得られる測定データは、カットオフ値λｓよりも短周期の波形に由来するデータであるため、粗化粒子に由来するデータを除去したものであると理解できる。これを踏まえると、カットオフ値λｓが２μｍのλｓフィルタを適用せずに算出される表面性状パラメータと、このλｓフィルタを適用して算出される表面性状パラメータとの差分は、オイルピットの情報が除去された表面処理層の情報、すなわち、表面処理層を構成する粗化粒子の情報であるといえる。 In the analysis of surface roughness measurement data, the present inventors found that surface texture parameters calculated by applying a λs filter with a cutoff value λs of 2 μm and surface texture parameters calculated without applying this λs filter By using a combination of rice field.
Here, the λs filter is a profile filter that greatly attenuates the amplitude of waveforms with wavelengths smaller than the cutoff value λs. The λs filter corresponds to the S filter in ISO 25178-2:2012. The amount by which the λs filter attenuates the amplitude depends on the wavelength of the waveform. At wavelengths with a cutoff value λs, the amplitude is attenuated to 50% of its original value, and at waveforms with shorter wavelengths, the amplitude is attenuated more.
The cutoff value λs of 2 μm is a size positioned between the size of the roughening particles forming the surface treatment layer and the size of the oil pit. Since the measurement data obtained by setting the cutoff value λs to 2 μm is data derived from a waveform with a period shorter than the cutoff value λs, it is understood that the data derived from roughening particles are removed. can. Based on this, the difference between the surface texture parameter calculated without applying the λs filter with a cutoff value λs of 2 μm and the surface texture parameter calculated using this λs filter is the oil pit information. It can be said that it is the information of the removed surface treatment layer, that is, the information of the roughening particles constituting the surface treatment layer.
　本発明者らは、上記の知見に基づいて、負荷曲線から得られる様々な表面性状パラメータの解析を行ったところ、表面処理層における下記式（１）で表されるＳｋの変化率が、表面処理層を構成する平均的な大きさの粗化粒子の付着量と密接に関係していることを見出した。
　Ｓｋの変化率＝（Ｐ２－Ｐ１）／Ｐ２×１００　・・・（１）
　式中、Ｐ１は、カットオフ値λｓが２μｍのλｓフィルタを適用して算出されるＳｋであり、Ｐ２は、前記λｓフィルタを適用せずに算出されるＳｋである。 Based on the above knowledge, the present inventors analyzed various surface property parameters obtained from the load curve, and found that the rate of change of Sk represented by the following formula (1) in the surface treatment layer was It was found to be closely related to the adhesion amount of average-sized roughening particles forming the treated layer.
Change rate of Sk=(P2-P1)/P2×100 (1)
In the formula, P1 is Sk calculated by applying a λs filter with a cutoff value λs of 2 μm, and P2 is Sk calculated without applying the λs filter.
　ここで、表面処理層を構成する粗化粒子及びＳｋを説明するための模式的な概略図を図２に示す。図２に示されるように、表面処理層は、平均的な大きさの粗化粒子Ａ、過成長した粗化粒子Ｂを含む。Ｓｋは、上記で既に説明したように、銅箔表面の比較的平滑な部分に形成された平均的な大きさの粗化粒子Ａの付着量に相関すると考えられる。Ｓｋはオイルピットなどのマクロな形状の寄与を少なからず受けており、表面処理層の情報をさらに精確に読み取るには、マクロな形状の寄与を除去する必要がある。Ｐ１は、粗化粒子に由来する情報を除去したＳｋの値、言い換えると、オイルピットなどに由来する情報が残ったＳｋの値であると解釈できる。Ｐ２とＰ１の差をとることは、Ｓｋに含まれるオイルピットなどのマクロな形状に由来する情報を除去することを意味する。その結果、平均的な大きさの粗化粒子Ａと相関のある情報を精度良く抽出することができる。
　銅箔表面の比較的平滑な部分に形成された平均的な大きさの粗化粒子Ａは、樹脂基材と表面処理層との接着力に大きく関係すると考えられる。過成長した（粗大な）粗化粒子Ｂは粗化折れに繋がり、過小な粗化粒子はそもそも樹脂基材に食い込まないと考えられる。したがって、平均的な大きさの粗化粒子Ａの付着量と関係するＳｋの変化率が適切な範囲に制御された表面処理銅箔とすることにより、樹脂基材との接着性を向上させることが可能となる。
　このような観点から、Ｓｋの変化率が２３．０～４５．０％である本発明の実施形態に係る表面処理銅箔は、樹脂基材に対する十分な接着力を示す。Ｓｋの変化率は、この効果を安定して得る観点から、好ましくは２３．０～４０．０％、より好ましくは２３．０～３６．０％である。 FIG. 2 shows a schematic diagram for explaining the roughening particles and Sk that constitute the surface treatment layer. As shown in FIG. 2, the surface treatment layer includes average-sized roughening particles A and overgrown roughening particles B. As shown in FIG. As already explained above, Sk is considered to correlate with the adherence amount of average-sized roughening particles A formed on the relatively smooth portion of the copper foil surface. Sk is not a little affected by macroscopic shapes such as oil pits, and in order to read the information of the surface treatment layer more accurately, it is necessary to remove the contribution of macroscopic shapes. P1 can be interpreted as the value of Sk from which the information derived from the roughening particles has been removed, in other words, the value of Sk from which the information derived from the oil pit or the like remains. Taking the difference between P2 and P1 means removing information derived from macroscopic shapes such as oil pits included in Sk. As a result, it is possible to accurately extract information correlated with the roughened particles A having an average size.
It is considered that the average-sized roughened particles A formed on the relatively smooth portion of the copper foil surface have a great relationship with the adhesive strength between the resin substrate and the surface treatment layer. It is thought that overgrown (coarse) roughened particles B lead to roughening breakage, and excessively small roughened particles do not bite into the resin substrate in the first place. Therefore, it is possible to improve the adhesiveness to the resin substrate by using a surface-treated copper foil in which the change rate of Sk, which is related to the amount of average-sized roughening particles A attached, is controlled within an appropriate range. becomes possible.
From this point of view, the surface-treated copper foil according to the embodiment of the present invention having a rate of change in Sk of 23.0 to 45.0% exhibits sufficient adhesion to resin substrates. The change rate of Sk is preferably 23.0 to 40.0%, more preferably 23.0 to 36.0%, from the viewpoint of stably obtaining this effect.
　表面処理層は、上記のλｓフィルタを適用せずに算出されるＳｋｕ（クルトシス）が２．５０～４．５０であることが好ましい。
　Ｓｋｕは平均高さを基準にし、高さのヒストグラムを作成した場合の当該ヒストグラムの尖り具合（尖度）を表現するパラメータである。例えば、Ｓｋｕ＝３．００の場合、高さ分布が正規分布であることを意味する。また、Ｓｋｕ＞３．００の場合、数値が大きくなるほど、高さ分布が集中していることを意味する。逆に、Ｓｋｕ＜３．００の場合、数値が小さくなるほど、高さ分布が分散していることを意味する。 The surface treatment layer preferably has an Sku (kurtosis) of 2.50 to 4.50 calculated without applying the λs filter.
Sku is a parameter that expresses the sharpness (kurtosis) of a height histogram created based on the average height. For example, Sku=3.00 means that the height distribution is a normal distribution. Also, in the case of Sku>3.00, the larger the numerical value, the more concentrated the height distribution. Conversely, when Sku<3.00, the smaller the value, the more dispersed the height distribution.
　本発明の実施形態に係る表面処理銅箔は表面に凹凸を有しており、当該凹凸は銅箔と樹脂基材との接着性の向上に資する。表面処理層のＳｋｕは当該凹凸の高さ分布を評価する指標となる。
　表面処理層のＳｋｕが２．５０～４．５０であることは、高さ分布が正規分布又はそれに近い分布状態であることを意味する。一方、表面処理層のＳｋｕが２．５０未満であることは、表面処理層の高さ（銅箔表面からの高さ）が低い部分と高い部分とが様々に入り交じった結果、高さ分布が偏っていない分布状態であることを意味する。表面処理層のＳｋｕが４．５０より大きいことは、高さ分布が偏っている分布状態であること、すなわち、表面処理層の表面は、ある高さの部分が突出して多くを占めている状態であることを意味する。
　表面処理層の高さ分布が正規分布又はそれに近い分布状態は、例えば、銅箔の表面に粗化処理層を形成する場合に、銅箔表面の凸部において過成長した粒子、すなわち粗化粒子や、銅箔表面の凹部周辺（凸部の端部）において粒子が形成されていない箇所が少ないことを意味する。したがって、表面処理層のＳｋｕが２．５０～４．５０であることは、銅箔表面の凸部に形成される粒子の過成長が抑制され、また、銅箔表面の凹部周辺にも粒子が形成されている状態を意味する。 The surface-treated copper foil according to the embodiment of the present invention has unevenness on the surface, and the unevenness contributes to the improvement of adhesion between the copper foil and the resin substrate. The Sku of the surface treatment layer serves as an index for evaluating the height distribution of the unevenness.
The Sku of the surface treatment layer being 2.50 to 4.50 means that the height distribution is a normal distribution or a distribution state close thereto. On the other hand, if the Sku of the surface treatment layer is less than 2.50, the height distribution means that the distribution is unbiased. If the Sku of the surface treatment layer is greater than 4.50, it means that the height distribution is uneven, that is, the surface of the surface treatment layer has a portion with a certain height that protrudes and occupies a large portion. means that
The height distribution of the surface treatment layer is a normal distribution or a distribution state close to it, for example, when a roughening treatment layer is formed on the surface of the copper foil, particles overgrown on the convex portions of the copper foil surface, that is, roughening particles Also, it means that there are few places where particles are not formed around the recesses (edges of the protrusions) on the surface of the copper foil. Therefore, when the Sku of the surface treatment layer is 2.50 to 4.50, the overgrowth of particles formed on the convex portions of the copper foil surface is suppressed, and the particles are also formed around the concave portions on the copper foil surface. It means the state of being formed.
　粗化粒子が多い表面処理銅箔も、粒子が形成されていない箇所がある表面処理銅箔も、樹脂基材との接着性の観点からは好ましくない。例えば、粗化粒子が多い表面処理銅箔では、樹脂基材との接合後、表面処理銅箔を剥離させる力を付与すると、粗化粒子に応力が集中して折れ易くなる結果、却って樹脂基材に対する接着力が低下すると考えられる。また、粒子が形成されていない箇所がある表面処理銅箔では、粒子によるアンカー効果を十分に確保することができなくなり、表面処理銅箔と樹脂基材との接着力が低下すると考えられる。
　したがって、樹脂基材に対する接着力を安定して得る観点から、表面処理層のＳｋｕは、下限値が好ましくは２．９０、上限値が好ましくは４．１０である。
　なお、表面処理層のＳｋｕは、ＩＳＯ　２５１７８－２：２０１２に準拠し、表面粗さを測定し、測定データから算出した輪郭曲線を解析することによって特定することができる。 A surface-treated copper foil with a large number of roughened particles and a surface-treated copper foil with portions where particles are not formed are not preferable from the viewpoint of adhesiveness to a resin substrate. For example, in a surface-treated copper foil with a large number of roughened particles, if a force is applied to peel off the surface-treated copper foil after bonding to the resin base material, the stress will concentrate on the roughened particles, making it easier to break. It is thought that the adhesive force to the material is reduced. In addition, it is considered that a surface-treated copper foil having a portion where particles are not formed cannot sufficiently ensure the anchoring effect of the particles, and the adhesive strength between the surface-treated copper foil and the resin substrate decreases.
Therefore, from the viewpoint of stably obtaining adhesive strength to the resin substrate, the lower limit of Sku of the surface treatment layer is preferably 2.90, and the upper limit is preferably 4.10.
The Sku of the surface treatment layer can be specified by measuring the surface roughness and analyzing the contour curve calculated from the measurement data in accordance with ISO 25178-2:2012.
　表面処理層は、上記のλｓフィルタを適用せずに算出されるＳｑ（二乗平均平方根高さ）が０．２０～０．６０μｍであることが好ましい。Ｓｑは、ＩＳＯ　２５１７８－２：２０１２に規定される高さ方向のパラメータであり、表面処理層の表面における凸部の高さのバラツキを表す。
　表面処理層のＳｑが大きいということは、表面処理層の表面における凸部の高さのバラツキが大きいということである。Ｓｑが大きすぎる（凸部の高さのバラツキが大きすぎる）と、工業製品としての品質管理の観点から問題になる場合がある。そのため、表面処理層のＳｑを上記の範囲とすることにより、凸部の高さのバラツキを多少許容して生産性を確保しつつ、適切な品質管理を行うことができる。このような効果を安定して得る観点から、表面処理層のＳｑは、下限値が好ましくは０．２６μｍ、より好ましくは０．３０μｍ、更に好ましくは０．３４μｍであり、上限値が好ましくは０．５３μｍ、より好ましくは０．４８μｍ、更に好ましくは０．４３μｍである。
　なお、表面処理層のＳｑは、ＩＳＯ　２５１７８－２：２０１２に準拠し、表面粗さを測定し、測定データから算出した輪郭曲線を解析することによって特定することができる。 The surface treatment layer preferably has an Sq (root mean square height) of 0.20 to 0.60 μm calculated without applying the λs filter. Sq is a parameter in the height direction defined in ISO 25178-2:2012, and represents the height variation of the protrusions on the surface of the surface treatment layer.
A large Sq of the surface treatment layer means that the height of the protrusions on the surface of the surface treatment layer varies greatly. If Sq is too large (variation in the height of the convex portion is too large), it may pose a problem from the viewpoint of quality control as an industrial product. Therefore, by setting the Sq of the surface treatment layer within the above range, it is possible to perform appropriate quality control while ensuring productivity by allowing some variation in the height of the protrusions. From the viewpoint of stably obtaining such effects, the Sq of the surface treatment layer preferably has a lower limit of 0.26 μm, more preferably 0.30 μm, still more preferably 0.34 μm, and an upper limit of preferably 0. 0.53 μm, more preferably 0.48 μm, even more preferably 0.43 μm.
The Sq of the surface treatment layer can be specified by measuring the surface roughness and analyzing the contour curve calculated from the measurement data in accordance with ISO 25178-2:2012.
　表面処理層は、上記のλｓフィルタを適用せずに算出されるＳａ（算術平均高さ）が０．２０～０．４０μｍであることが好ましい。Ｓａは、ＩＳＯ　２５１７８－２：２０１２に規定される高さ方向のパラメータであり、平均面からの高低差の平均を表す。
　表面処理層のＳａが大きいと、表面処理層の表面が粗くなるため、表面処理銅箔を樹脂基材に接着した場合にアンカー効果が発揮され易くなる。一方で、表面処理層のＳａが大きすぎると、表面処理銅箔と樹脂基材とを接着した銅張積層板を加工して回路基板を作製した場合、表面処理銅箔の表皮効果によって伝送損失が大きくなる。そのため、表面処理層のＳａを上記の範囲とすることにより、樹脂基材に対する表面処理銅箔の接着力の確保と伝送損失の抑制とのバランスを確保することができる。このような効果を安定して得る観点から、表面処理層のＳａは、下限値が好ましくは０．２３μｍ、より好ましくは０．２４μｍであり、上限値が好ましくは０．３５μｍである。
　また、表皮効果による伝送損失の抑制及び工業製品としての品質管理のし易さを重視した場合、表面処理層は、Ｓａが０．２０～０．３２μｍであり、且つＳｑが０．２６～０．４０μｍであることが好ましい。
　なお、表面処理層のＳａは、ＩＳＯ　２５１７８－２：２０１２に準拠し、表面粗さを測定し、測定データから算出した輪郭曲線を解析することによって特定することができる。 The surface treatment layer preferably has an Sa (arithmetic mean height) of 0.20 to 0.40 μm calculated without applying the λs filter. Sa is a parameter in the height direction defined in ISO 25178-2:2012 and represents the average height difference from the average plane.
If the Sa of the surface-treated layer is large, the surface of the surface-treated layer becomes rough, so that the anchor effect is likely to be exhibited when the surface-treated copper foil is adhered to a resin base material. On the other hand, if the Sa of the surface-treated layer is too large, when a circuit board is fabricated by processing a copper-clad laminate in which the surface-treated copper foil and the resin substrate are bonded, transmission loss will occur due to the skin effect of the surface-treated copper foil. becomes larger. Therefore, by setting the Sa of the surface treatment layer within the above range, it is possible to ensure a balance between securing the adhesion of the surface-treated copper foil to the resin substrate and suppressing the transmission loss. From the viewpoint of stably obtaining such effects, the lower limit of Sa in the surface treatment layer is preferably 0.23 μm, more preferably 0.24 μm, and the upper limit is preferably 0.35 μm.
In addition, when emphasizing the suppression of transmission loss due to the skin effect and the ease of quality control as an industrial product, the surface treatment layer has a Sa of 0.20 to 0.32 μm and an Sq of 0.26 to 0. 0.40 μm is preferred.
The Sa of the surface treatment layer can be specified by measuring the surface roughness and analyzing the contour curve calculated from the measurement data according to ISO 25178-2:2012.
　表面処理層は、上記のλｓフィルタを適用せずに算出されるＳｓｋ（スキューネス）が－１．１０～０．６０であることが好ましい。
　Ｓｓｋは平均高さを基準にし、高さのヒストグラムを作成した場合の当該ヒストグラムの偏り具合（歪度）を表現するパラメータである。例えば、Ｓｓｋ＝０．００の場合、高さ分布が平均線に対して対称であることを意味する。また、Ｓｓｋ＞０．００の場合、数値が大きくなるほど、高さ分布が平均線に対して下側に偏っていることを意味する。逆に、Ｓｓｋ＜０．００の場合、数値が小さくなるほど、高さ分布が平均線に対して上側に偏っていることを意味する。したがって、表面処理層のＳｓｋは、Ｓｋｕと同様に、表面処理層の凹凸の高さ分布を評価する指標となる。
　Ｓｓｋが－１．１０～０．６０であることは、例えば、銅箔の表面に粗化処理層を形成する場合に、銅箔表面の凸部において過成長した粗化粒子、すなわち粗大な粗化粒子や、銅箔表面の凹部周辺（凸部の端部）において粗化粒子が形成されていない箇所が少ないことを意味する。一方、－１．１０未満であると、銅箔表面の凹部周辺において粗化粒子が形成されていない箇所が多い状態となる。また、Ｓｓｋが０．６０超過であると、銅箔表面の凸部において過成長した粗化粒子が多い状態となる。
　樹脂基材に対する接着力を安定して得る観点から、表面処理層のＳｓｋは、上限値が好ましくは０．４０、下限値が好ましくは－０．８０である。
　なお、表面処理層のＳｓｋは、ＩＳＯ　２５１７８－２：２０１２に準拠し、表面粗さを測定し、測定データから算出した輪郭曲線を解析することによって特定することができる。 The surface treatment layer preferably has an Ssk (skewness) of −1.10 to 0.60 calculated without applying the λs filter.
Ssk is a parameter that expresses the degree of deviation (skewness) of a height histogram created with the average height as a reference. For example, Ssk=0.00 means that the height distribution is symmetrical about the mean line. Moreover, when Ssk>0.00, the larger the numerical value, the more the height distribution is biased downward with respect to the average line. Conversely, when Ssk<0.00, the smaller the value, the more the height distribution is biased upward with respect to the average line. Therefore, Ssk of the surface treatment layer serves as an index for evaluating the height distribution of unevenness of the surface treatment layer, like Sku.
The fact that Ssk is -1.10 to 0.60 means that, for example, when a roughening treatment layer is formed on the surface of the copper foil, roughening particles overgrown on the convex portions of the copper foil surface, that is, coarse roughness It means that there are few roughening particles and there are few places where roughening particles are not formed around the recesses (ends of the protrusions) on the copper foil surface. On the other hand, when it is less than -1.10, there are many places where the roughening particles are not formed around the recesses on the copper foil surface. Moreover, when Ssk is more than 0.60, a large number of overgrown roughened particles are present in the convex portions of the copper foil surface.
From the viewpoint of stably obtaining adhesive strength to the resin substrate, the upper limit of Ssk of the surface treatment layer is preferably 0.40, and the lower limit is preferably -0.80.
The Ssk of the surface treatment layer can be specified by measuring the surface roughness in accordance with ISO 25178-2:2012 and analyzing the contour curve calculated from the measurement data.
　表面処理層の種類は、特に限定されず、当該技術分野において公知の各種表面処理層を用いることができる。
　表面処理層の例としては、粗化処理層、耐熱処理層、防錆処理層、クロメート処理層、シランカップリング処理層などが挙げられる。これらの層は、単一又は２種以上を組み合わせて用いることができる。その中でも表面処理層は、樹脂基材との接着性の観点から、粗化処理層を含有することが好ましい。
　また、表面処理層が、耐熱処理層、防錆処理層、クロメート処理層及びシランカップリング処理層からなる群から選択される１種以上の層を含有する場合、これらの層は粗化処理層上に設けられることが好ましい。 The type of surface treatment layer is not particularly limited, and various surface treatment layers known in the art can be used.
Examples of surface treatment layers include roughening treatment layers, heat resistance treatment layers, rust prevention treatment layers, chromate treatment layers, silane coupling treatment layers, and the like. These layers can be used singly or in combination of two or more. Among them, the surface treatment layer preferably contains a roughening treatment layer from the viewpoint of adhesion to the resin substrate.
In addition, when the surface treatment layer contains one or more layers selected from the group consisting of a heat-resistant treatment layer, an antirust treatment layer, a chromate treatment layer and a silane coupling treatment layer, these layers are roughening treatment layers. It is preferably provided above.
　ここで、一例として、銅箔の一方の面に粗化処理層を有する表面処理銅箔の模式的な拡大断面図を図３に示す。
　図３に示されるように、銅箔１０の一方の面に形成された粗化処理層は、粗化粒子２０と、粗化粒子２０の少なくとも一部を被覆するかぶせめっき層３０とを含む。粗化粒子２０は、銅箔１０表面の凸部１１の中央付近だけでなく凹部１２周辺（凸部１１の端部）にも形成されている。また、銅箔１０表面の凸部１１に形成された粗化粒子２０は、めっき液に微量のタングステン化合物を添加することにより、過成長が抑制されている。そのため、この粗化粒子２０は粒径が大きい粒子に過成長しておらず、各方向に向かって成長した複雑な形状を有している。表面処理層のＳｋの変化率を上記の範囲に制御することにより、このような構造をとることができると考えられる。 Here, as an example, FIG. 3 shows a schematic enlarged cross-sectional view of a surface-treated copper foil having a roughened layer on one surface of the copper foil.
As shown in FIG. 3 , the roughening treatment layer formed on one surface of copper foil 10 includes roughening particles 20 and covering plating layer 30 covering at least part of roughening particles 20 . The roughening particles 20 are formed not only near the center of the protrusions 11 on the surface of the copper foil 10 but also around the recesses 12 (ends of the protrusions 11). Moreover, overgrowth of the roughening particles 20 formed on the convex portions 11 of the copper foil 10 is suppressed by adding a small amount of a tungsten compound to the plating solution. Therefore, the roughened particles 20 do not overgrow into particles having a large particle size, and have a complicated shape that grows in each direction. It is considered that such a structure can be obtained by controlling the rate of change of Sk of the surface treatment layer within the above range.
　粗化粒子２０としては、特に限定されないが、銅、ニッケル、コバルト、リン、タングステン、ヒ素、モリブデン、クロム及び亜鉛からなる群から選択される単一の元素、又はこれらの元素の２種以上を含む合金から形成することができる。その中でも粗化粒子２０は、銅又は銅合金、特に銅から形成されることが好ましい。
　かぶせめっき層３０としては、特に限定されないが、銅、銀、金、ニッケル、コバルト、亜鉛などから形成することができる。 The roughening particles 20 are not particularly limited, but may be a single element selected from the group consisting of copper, nickel, cobalt, phosphorus, tungsten, arsenic, molybdenum, chromium and zinc, or two or more of these elements. It can be formed from an alloy containing Among them, the roughening particles 20 are preferably made of copper or a copper alloy, particularly copper.
The covering plating layer 30 is not particularly limited, but can be made of copper, silver, gold, nickel, cobalt, zinc, or the like.
　粗化処理層は、電気めっきによって形成することができる。特に、粗化粒子２０は、微量のタングステン化合物を添加しためっき液を用いた電気めっきによって形成することができる。
　タングステン化合物としては、特に限定されないが、例えば、タングステン酸ナトリウム（Ｎａ2ＷＯ4）などを用いることができる。
　めっき液におけるタングステン化合物の含有量としては、１ｐｐｍ以上とすることが好ましい。このような含有量であれば、凸部１１に形成された粗化粒子２０の過成長を抑制するとともに、凹部１２周辺に粗化粒子２０を形成させ易くすることができる。なお、タングステン化合物の含有量の上限値は、特に限定されないが、電気抵抗の増大を抑制する観点から、２０ｐｐｍであることが好ましい。 The roughened layer can be formed by electroplating. In particular, the roughened particles 20 can be formed by electroplating using a plating solution containing a trace amount of tungsten compound.
Although the tungsten compound is not particularly limited, for example, sodium tungstate (Na 2 WO 4 ) can be used.
The content of the tungsten compound in the plating solution is preferably 1 ppm or more. With such a content, overgrowth of roughening particles 20 formed on convex portions 11 can be suppressed, and roughening particles 20 can be easily formed around concave portions 12 . Although the upper limit of the content of the tungsten compound is not particularly limited, it is preferably 20 ppm from the viewpoint of suppressing an increase in electrical resistance.
　粗化処理層を形成する際の電気めっきの条件は、使用する電気めっき装置などに応じて調整すればよく特に限定されないが、典型的な条件は以下の通りである。なお、各電気めっきは、１回であってもよいし、複数回行ってもよい。
（粗化粒子２０の形成条件）
　めっき液組成：５～１５ｇ／ＬのＣｕ、４０～１００ｇ／Ｌの硫酸、１～６ｐｐｍのタングステン酸ナトリウム
　めっき液温度：２０～５０℃
　電気めっき条件：電流密度３０～９０Ａ／ｄｍ2、時間０．１～８秒 Electroplating conditions for forming the roughened layer are not particularly limited and may be adjusted according to the electroplating apparatus used, but typical conditions are as follows. Each electroplating may be performed once or may be performed multiple times.
(Conditions for forming roughening particles 20)
Plating solution composition: 5-15 g/L Cu, 40-100 g/L sulfuric acid, 1-6 ppm sodium tungstate Plating solution temperature: 20-50°C
Electroplating conditions: current density 30-90 A/dm 2 , time 0.1-8 seconds
（かぶせめっき層３０の形成条件）
　めっき液組成：１０～３０ｇ／ＬのＣｕ、７０～１３０ｇ／Ｌの硫酸
　めっき液温度：３０～６０℃
　電気めっき条件：電流密度４．８～１５Ａ／ｄｍ2、時間０．１～８秒 (Conditions for forming cover plating layer 30)
Plating solution composition: 10-30 g/L Cu, 70-130 g/L sulfuric acid Plating solution temperature: 30-60°C
Electroplating conditions: current density 4.8-15 A/dm 2 , time 0.1-8 seconds
　耐熱処理層及び防錆処理層としては、特に限定されず、当該技術分野において公知の材料から形成することができる。なお、耐熱処理層は防錆処理層としても機能することがあるため、耐熱処理層及び防錆処理層として、耐熱処理層及び防錆処理層の両方の機能を有する１つの層を形成してもよい。
　耐熱処理層及び／又は防錆処理層としては、ニッケル、亜鉛、錫、コバルト、モリブデン、銅、タングステン、リン、ヒ素、クロム、バナジウム、チタン、アルミニウム、金、銀、白金族元素、鉄、タンタルの群から選択される１種以上の元素（金属、合金、酸化物、窒化物、硫化物などのいずれの形態であってもよい）を含む層とすることができる。その中でも耐熱処理層及び／又は防錆処理層はＮｉ－Ｚｎ層であることが好ましい。 The heat-resistant layer and the rust-proof layer are not particularly limited, and can be formed from materials known in the art. In addition, since the heat-resistant treatment layer may also function as a rust-preventive treatment layer, a single layer having the functions of both the heat-resistant treatment layer and the rust-preventive treatment layer is formed as the heat-resistant treatment layer and the rust-preventive treatment layer. good too.
As the heat-resistant layer and/or rust-proof layer, nickel, zinc, tin, cobalt, molybdenum, copper, tungsten, phosphorus, arsenic, chromium, vanadium, titanium, aluminum, gold, silver, platinum group elements, iron, tantalum It can be a layer containing one or more elements selected from the group of (any form of metal, alloy, oxide, nitride, sulfide, etc.). Among them, the heat-resistant layer and/or the rust-proof layer is preferably a Ni—Zn layer.
　耐熱処理層及び防錆処理層は、電気めっきによって形成することができる。その条件は、使用する電気めっき装置に応じて調整すればよく特に限定されないが、一般的な電気めっき装置を用いて耐熱処理層（Ｎｉ－Ｚｎ層）を形成する際の条件は以下の通りである。なお、電気めっきは、１回であってもよいし、複数回行ってもよい。
　めっき液組成：１～３０ｇ／ＬのＮｉ、１～３０ｇ／ＬのＺｎ
　めっき液ｐＨ：２～５
　めっき液温度：３０～５０℃
　電気めっき条件：電流密度０．１～１０Ａ／ｄｍ2、時間０．１～５秒 The heat-resistant layer and the rust-proof layer can be formed by electroplating. The conditions may be adjusted according to the electroplating apparatus to be used, and are not particularly limited, but the conditions for forming the heat-resistant layer (Ni—Zn layer) using a general electroplating apparatus are as follows. be. Electroplating may be performed once or multiple times.
Plating solution composition: 1 to 30 g/L Ni, 1 to 30 g/L Zn
Plating solution pH: 2-5
Plating solution temperature: 30-50°C
Electroplating conditions: current density 0.1 to 10 A/dm 2 , time 0.1 to 5 seconds
　クロメート処理層としては、特に限定されず、当該技術分野において公知の材料から形成することができる。
　ここで、本明細書において「クロメート処理層」とは、無水クロム酸、クロム酸、二クロム酸、クロム酸塩又は二クロム酸塩を含む液で形成された層を意味する。クロメート処理層は、コバルト、鉄、ニッケル、モリブデン、亜鉛、タンタル、銅、アルミニウム、リン、タングステン、錫、ヒ素、チタンなどの元素（金属、合金、酸化物、窒化物、硫化物などのいずれの形態であってもよい）を含む層であることができる。クロメート処理層の例としては、無水クロム酸又は二クロム酸カリウム水溶液で処理したクロメート処理層、無水クロム酸又は二クロム酸カリウム及び亜鉛を含む処理液で処理したクロメート処理層などが挙げられる。 The chromate treatment layer is not particularly limited, and can be formed from materials known in the technical field.
As used herein, the term "chromate treatment layer" means a layer formed of a liquid containing chromic anhydride, chromic acid, dichromic acid, chromate, or dichromate. The chromate treatment layer contains elements such as cobalt, iron, nickel, molybdenum, zinc, tantalum, copper, aluminum, phosphorus, tungsten, tin, arsenic, titanium, etc. (any metal, alloy, oxide, nitride, sulfide, etc.) morphology). Examples of the chromate-treated layer include a chromate-treated layer treated with an aqueous solution of chromic acid anhydride or potassium dichromate, a chromate-treated layer treated with a treatment liquid containing chromic anhydride or potassium dichromate and zinc, and the like.
　クロメート処理層は、浸漬クロメート処理、電解クロメート処理などの公知の方法によって形成することができる。それらの条件は、特に限定されないが、例えば、一般的なクロメート処理層を形成する際の条件は以下の通りである。なお、クロメート処理は、１回であってもよいし、複数回行ってもよい。
　クロメート液組成：１～１０ｇ／ＬのＫ2Ｃｒ2Ｏ7、０．０１～１０ｇ／ＬのＺｎ
　クロメート液ｐＨ：２～５
　クロメート液温度：３０～５５℃
　電解条件：電流密度０．１～１０Ａ／ｄｍ2、時間０．１～５秒（電解クロメート処理の場合） The chromate treatment layer can be formed by known methods such as immersion chromate treatment and electrolytic chromate treatment. These conditions are not particularly limited, but, for example, the conditions for forming a general chromate treatment layer are as follows. The chromate treatment may be performed once or multiple times.
Chromate liquid composition: 1-10 g/L K 2 Cr 2 O 7 , 0.01-10 g/L Zn
Chromate solution pH: 2-5
Chromate liquid temperature: 30-55°C
Electrolytic conditions: current density 0.1 to 10 A/dm 2 , time 0.1 to 5 seconds (for electrolytic chromate treatment)
　シランカップリング処理層としては、特に限定されず、当該技術分野において公知の材料から形成することができる。
　ここで、本明細書において「シランカップリング処理層」とは、シランカップリング剤で形成された層を意味する。
　シランカップリング剤としては、特に限定されず、当該技術分野において公知のものを用いることができる。シランカップリング剤の例としては、アミノ系シランカップリング剤、エポキシ系シランカップリング剤、メルカプト系シランカップリング剤、メタクリロキシ系シランカップリング剤、ビニル系シランカップリング剤、イミダゾール系シランカップリング剤、トリアジン系シランカップリング剤などが挙げられる。これらの中でも、アミノ系シランカップリング剤、エポキシ系シランカップリング剤が好ましい。上記のシランカップリング剤は、単独又は２種以上を組み合わせて用いることができる。
　代表的なシランカップリング処理層の形成方法としては、上述のシランカップリング剤の１～３体積％水溶液を塗布し、乾燥させることでシランカップリング処理層を形成する方法が挙げられる。 The silane coupling-treated layer is not particularly limited, and can be formed from materials known in the art.
Here, the term "silane coupling treated layer" as used herein means a layer formed with a silane coupling agent.
The silane coupling agent is not particularly limited, and those known in the art can be used. Examples of silane coupling agents include amino-based silane coupling agents, epoxy-based silane coupling agents, mercapto-based silane coupling agents, methacryloxy-based silane coupling agents, vinyl-based silane coupling agents, and imidazole-based silane coupling agents. , triazine-based silane coupling agents, and the like. Among these, amino-based silane coupling agents and epoxy-based silane coupling agents are preferred. Said silane coupling agent can be used individually or in combination of 2 or more types.
A representative method for forming a silane coupling-treated layer includes a method of forming a silane coupling-treated layer by applying a 1 to 3% by volume aqueous solution of the above-mentioned silane coupling agent and drying it.
　銅箔１０としては、特に限定されず、電解銅箔又は圧延銅箔のいずれであってもよい。
　電解銅箔は、硫酸銅めっき浴からチタン又はステンレスのドラム上に銅を電解析出させることによって一般に製造されるが、回転ドラム側に形成される平坦なＳ面（シャイン面）と、Ｓ面の反対側に形成されるＭ面（マット面）とを有する。電解銅箔のＭ面は、一般に微小な凹凸部を有している。また、電解銅箔のＳ面は、研磨時に形成された回転ドラムの研磨スジが転写されるため、微小な凹凸部を有する。
　また、圧延銅箔は、圧延時に圧延油によってオイルピットが形成されるため、微小な凹凸部を表面に有する。 The copper foil 10 is not particularly limited, and may be either an electrolytic copper foil or a rolled copper foil.
Electrodeposited copper foil is generally produced by electrolytically depositing copper from a copper sulfate plating bath onto a titanium or stainless steel drum. and an M surface (matte surface) formed on the opposite side of the . The M side of the electrolytic copper foil generally has minute unevenness. In addition, the S side of the electrolytic copper foil has fine irregularities because polishing streaks formed on the rotary drum during polishing are transferred to the S side.
In addition, the rolled copper foil has oil pits formed by the rolling oil during rolling, so that the rolled copper foil has minute irregularities on its surface.
　銅箔１０の材料としては、特に限定されないが、銅箔１０が圧延銅箔の場合、プリント配線板の回路パターンとして通常使用されるタフピッチ銅（ＪＩＳ　Ｈ３１００　合金番号Ｃ１１００）、無酸素銅（ＪＩＳ　Ｈ３１００　合金番号Ｃ１０２０又はＪＩＳ　Ｈ３５１０　合金番号Ｃ１０１１）などの高純度の銅を用いることができる。また、例えば、Ｓｎ入り銅、Ａｇ入り銅、Ｃｒ、Ｚｒ又はＭｇなどを添加した銅合金、Ｎｉ及びＳｉなどを添加したコルソン系銅合金のような銅合金も用いることができる。なお、本明細書において「銅箔１０」とは、銅合金箔も含む概念である。 The material of the copper foil 10 is not particularly limited. High-purity copper such as alloy number C1020 or JIS H3510 alloy number C1011) can be used. Copper alloys such as Sn-containing copper, Ag-containing copper, copper alloys containing Cr, Zr, Mg, etc., and Corson copper alloys containing Ni, Si, etc. can also be used. In addition, in this specification, the "copper foil 10" is a concept including a copper alloy foil.
　銅箔１０の厚みは、特に限定されないが、例えば１～１０００μｍ、或いは１～５００μｍ、或いは１～３００μｍ、或いは３～１００μｍ、或いは５～７０μｍ、或いは６～３５μｍ、或いは９～１８μｍとすることができる。 The thickness of the copper foil 10 is not particularly limited. can.
　上記のような構成を有する表面処理銅箔は、当該技術分野において公知の方法に準じて製造することができる。ここで、表面処理層のＳｋの変化率などのパラメータは、表面処理層の形成条件、特に、上記した粗化処理層の形成条件などを調整することによって制御することができる。 The surface-treated copper foil having the configuration as described above can be produced according to a method known in the technical field. Here, the parameters such as the rate of change of Sk of the surface treatment layer can be controlled by adjusting the conditions for forming the surface treatment layer, particularly the conditions for forming the roughening treatment layer described above.
　本発明の実施形態に係る表面処理銅箔は、表面処理層のＳｋの変化率を２３．０～４５．０％に制御しているため、樹脂基材、特に高周波用途に好適な樹脂基材との接着性を高めることができる。 Since the surface-treated copper foil according to the embodiment of the present invention controls the rate of change of Sk of the surface treatment layer to 23.0 to 45.0%, it is a resin base material, especially a resin base material suitable for high frequency applications. can enhance the adhesion with.
　本発明の実施形態に係る銅張積層板は、上記の表面処理銅箔と、この表面処理銅箔の表面処理層に接着された樹脂基材とを備える。
　この銅張積層板は、上記の表面処理銅箔の表面処理層に樹脂基材を接着することによって製造することができる。
　樹脂基材としては、特に限定されず、当該技術分野において公知のものを用いることができる。樹脂基材の例としては、紙基材フェノール樹脂、紙基材エポキシ樹脂、合成繊維布基材エポキシ樹脂、ガラス布・紙複合基材エポキシ樹脂、ガラス布・ガラス不織布複合基材エポキシ樹脂、ガラス布基材エポキシ樹脂、ポリエステルフィルム、ポリイミド樹脂、液晶ポリマー、フッ素樹脂などが挙げられる。これらの中でも樹脂基材はポリイミド樹脂が好ましい。 A copper-clad laminate according to an embodiment of the present invention includes the surface-treated copper foil described above and a resin substrate adhered to the surface-treated layer of the surface-treated copper foil.
This copper-clad laminate can be produced by adhering a resin substrate to the surface-treated layer of the surface-treated copper foil.
The resin substrate is not particularly limited, and those known in the art can be used. Examples of resin base materials include paper base phenol resin, paper base epoxy resin, synthetic fiber cloth base epoxy resin, glass cloth/paper composite base epoxy resin, glass cloth/glass nonwoven cloth composite base epoxy resin, glass Examples include cloth-based epoxy resins, polyester films, polyimide resins, liquid crystal polymers, and fluorine resins. Among these resin substrates, polyimide resin is preferable.
　表面処理銅箔と樹脂基材との接着方法としては、特に限定されず、当該技術分野において公知の方法に準じて行うことができる。例えば、表面処理銅箔と樹脂基材とを積層させて熱圧着すればよい。
　上記のようにして製造された銅張積層板は、プリント配線板の製造に用いることができる。 The method for bonding the surface-treated copper foil and the resin substrate is not particularly limited, and can be performed according to a method known in the art. For example, a surface-treated copper foil and a resin base material may be laminated and thermocompression bonded.
The copper-clad laminate manufactured as described above can be used for manufacturing a printed wiring board.
　本発明の実施形態に係る銅張積層板は、上記の表面処理銅箔を用いているため、樹脂基材、特に高周波用途に好適な樹脂基材との接着性を高めることができる。 Since the copper-clad laminate according to the embodiment of the present invention uses the surface-treated copper foil described above, it is possible to improve the adhesiveness to resin substrates, particularly resin substrates suitable for high-frequency applications.
　本発明の実施形態に係るプリント配線板は、上記の銅張積層板の表面処理銅箔をエッチングして形成された回路パターンを備える。
　このプリント配線板は、上記の銅張積層板の表面処理銅箔をエッチングして回路パターンを形成することによって製造することができる。回路パターンの形成方法としては、特に限定されず、サブトラクティブ法、セミアディティブ法などの公知の方法を用いることができる。その中でも、回路パターンの形成方法はサブトラクティブ法が好ましい。 A printed wiring board according to an embodiment of the present invention includes a circuit pattern formed by etching the surface-treated copper foil of the copper-clad laminate.
This printed wiring board can be produced by etching the surface-treated copper foil of the copper-clad laminate to form a circuit pattern. A method for forming a circuit pattern is not particularly limited, and known methods such as a subtractive method and a semi-additive method can be used. Among them, the subtractive method is preferable as the method of forming the circuit pattern.
　サブトラクティブ法によってプリント配線板を製造する場合、次のようにして行うことが好ましい。まず、銅張積層板の表面処理銅箔の表面にレジストを塗布、露光及び現像することによって所定のレジストパターンを形成する。次に、レジストパターンが形成されていない部分（不要部）の表面処理銅箔をエッチングによって除去して回路パターンを形成する。最後に、表面処理銅箔上のレジストパターンを除去する。
　なお、このサブトラクティブ法における各種条件は、特に限定されず、当該技術分野において公知の条件に準じて行うことができる。 When manufacturing a printed wiring board by a subtractive method, it is preferable to carry out as follows. First, a predetermined resist pattern is formed by applying a resist to the surface of the surface-treated copper foil of the copper clad laminate, exposing and developing the resist. Next, the circuit pattern is formed by removing the surface-treated copper foil from the portion where the resist pattern is not formed (unnecessary portion) by etching. Finally, the resist pattern on the surface-treated copper foil is removed.
Various conditions in this subtractive method are not particularly limited, and can be carried out according to conditions known in the technical field.
　本発明の実施形態に係るプリント配線板は、上記の銅張積層板を用いているため、樹脂基材、特に高周波用途に好適な樹脂基材と回路パターンとの間の接着性に優れている。 Since the printed wiring board according to the embodiment of the present invention uses the above copper clad laminate, it has excellent adhesion between the resin substrate, particularly the resin substrate suitable for high frequency applications, and the circuit pattern. .
　以下、本発明の実施形態を実施例によって更に具体的に説明するが、本発明はこれらの実施例によって何ら限定されるものではない。 The embodiments of the present invention will be described in more detail below with reference to examples, but the present invention is not limited by these examples.
（実施例１）
　厚さ１２μｍの圧延銅箔（ＪＸ金属株式会社製ＨＡ－Ｖ２箔）を準備し、一方の面を脱脂及び酸洗した後、表面処理層として粗化処理層、耐熱処理層（Ｎｉ－Ｚｎ層）、クロメート処理層及びシランカップリング処理層を順次形成することによって表面処理銅箔を得た。各処理層の形成条件は次の通りとした。
（１）粗化処理層
＜粗化粒子の形成条件＞
　めっき液組成：１１ｇ／ＬのＣｕ、５０ｇ／Ｌの硫酸、５ｐｐｍのタングステン（タングステン酸ナトリウム２水和物由来）
　めっき液温度：２７℃
　電気めっき条件：電流密度４６．８Ａ／ｄｍ2、時間１．０１秒
　電気めっき処理回数：２回 (Example 1)
Prepare a rolled copper foil (HA-V2 foil manufactured by JX Metals Co., Ltd.) with a thickness of 12 μm, degreasing and pickling one side, roughening treatment layer as a surface treatment layer, heat treatment layer (Ni-Zn layer ), a chromate-treated layer and a silane coupling-treated layer were sequentially formed to obtain a surface-treated copper foil. The conditions for forming each treated layer were as follows.
(1) Roughened layer <Conditions for forming roughened particles>
Plating solution composition: 11 g/L Cu, 50 g/L sulfuric acid, 5 ppm tungsten (from sodium tungstate dihydrate)
Plating solution temperature: 27°C
Electroplating conditions: current density 46.8 A/dm 2 , time 1.01 seconds Number of electroplating treatments: 2 times
＜かぶせめっき層の形成条件＞
　めっき液組成：２０ｇ／ＬのＣｕ、１００ｇ／Ｌの硫酸
　めっき液温度：５０℃
　電気めっき条件：電流密度９．６Ａ／ｄｍ2、時間１．４４秒
　電気めっき処理回数：２回 <Conditions for Forming Cover Plating Layer>
Plating solution composition: 20 g/L Cu, 100 g/L sulfuric acid Plating solution temperature: 50°C
Electroplating conditions: current density 9.6 A/dm 2 , time 1.44 seconds Number of electroplating treatments: 2 times
（２）耐熱処理層
＜Ｎｉ－Ｚｎ層の形成条件＞
　めっき液組成：２３．５ｇ／ＬのＮｉ、４．５ｇ／ＬのＺｎ
　めっき液ｐＨ：３．６
　めっき液温度：４０℃
　電気めっき条件：電流密度０．８８Ａ／ｄｍ2、時間０．７３秒
　電気めっき処理回数：１回 (2) Heat-resistant layer <Conditions for forming Ni—Zn layer>
Plating solution composition: 23.5 g/L Ni, 4.5 g/L Zn
Plating solution pH: 3.6
Plating solution temperature: 40°C
Electroplating conditions: current density 0.88 A/dm 2 , time 0.73 seconds Number of electroplating treatments: 1 time
（３）クロメート処理層
＜電解クロメート処理層の形成条件＞
　クロメート液組成：３ｇ／ＬのＫ2Ｃｒ2Ｏ7、０．３３ｇ／ＬのＺｎ
　クロメート液ｐＨ：３．７
　クロメート液温度：５５℃
　電解条件：電流密度１．４２Ａ／ｄｍ2、時間０．７３秒
　クロメート処理回数：２回 (3) Chromate-treated layer <Conditions for forming electrolytic chromate-treated layer>
Chromate liquid composition: 3 g/L K2Cr2O7 , 0.33 g/L Zn
Chromate solution pH: 3.7
Chromate liquid temperature: 55°C
Electrolysis conditions: current density 1.42 A/dm 2 , time 0.73 seconds Number of chromate treatments: 2 times
（４）シランカップリング処理層
　Ｎ－２－（アミノエチル）－３－アミノプロピルトリメトキシシランの１．２体積％水溶液を塗布し、乾燥させることでシランカップリング処理層を形成した。 (4) Silane Coupling Treated Layer A 1.2% by volume aqueous solution of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane was applied and dried to form a silane coupling treated layer.
（実施例２）
　以下の条件を変更したこと以外は実施例１と同様の条件で表面処理銅箔を得た。
＜粗化粒子の形成条件＞
　電気めっき条件：電流密度７４．８Ａ／ｄｍ2、時間０．５８秒
＜かぶせめっき層の形成条件＞
　電気めっき条件：電流密度１１．０Ａ／ｄｍ2、時間１．１０秒
＜Ｎｉ－Ｚｎ層の形成条件＞
　電気めっき条件：電流密度０．６８Ａ／ｄｍ2、時間０．５６秒
＜電解クロメート処理層の形成条件＞
　電解条件：電流密度１．９０Ａ／ｄｍ2、時間０．５６秒 (Example 2)
A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
<Conditions for Forming Roughened Particles>
Electroplating conditions: current density 74.8 A/dm 2 , time 0.58 seconds <Conditions for forming cover plating layer>
Electroplating conditions: current density 11.0 A/dm 2 , time 1.10 seconds <Conditions for Ni—Zn layer formation>
Electroplating conditions: current density 0.68 A/dm 2 , time 0.56 seconds <Conditions for forming electrolytic chromate treatment layer>
Electrolysis conditions: current density 1.90 A/dm 2 , time 0.56 seconds
（実施例３）
　以下の条件を変更したこと以外は実施例１と同様の条件で表面処理銅箔を得た。
＜粗化粒子の形成条件＞
　電気めっき条件：電流密度４８．７Ａ／ｄｍ2、時間１．０１秒
＜かぶせめっき層の形成条件＞
　電気めっき条件：電流密度８．２Ａ／ｄｍ2、時間１．４４秒
＜Ｎｉ－Ｚｎ層の形成条件＞
　電気めっき条件：電流密度０．７３Ａ／ｄｍ2、時間０．７３秒
＜電解クロメート処理層の形成条件＞
　電解条件：電流密度１．５１Ａ／ｄｍ2、時間０．７３秒 (Example 3)
A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
<Conditions for Forming Roughened Particles>
Electroplating conditions: current density 48.7 A/dm 2 , time 1.01 seconds <Conditions for forming cover plating layer>
Electroplating conditions: current density 8.2 A/dm 2 , time 1.44 seconds <Conditions for Ni—Zn layer formation>
Electroplating conditions: current density 0.73 A/dm 2 , time 0.73 seconds <Conditions for forming electrolytic chromate treatment layer>
Electrolysis conditions: current density 1.51 A/dm 2 , time 0.73 seconds
（実施例４）
　以下の条件を変更したこと以外は実施例１と同様の条件で表面処理銅箔を得た。
＜粗化粒子の形成条件＞
　めっき液組成：１１ｇ／ＬのＣｕ、５０ｇ／Ｌの硫酸、３ｐｐｍのタングステン（タングステン酸ナトリウム２水和物由来）
　電気めっき条件：電流密度３８．８Ａ／ｄｍ2、時間１．２７秒
＜かぶせめっき層の形成条件＞
　電気めっき条件：電流密度８．２Ａ／ｄｍ2、時間１．４４秒
＜Ｎｉ－Ｚｎ層の形成条件＞
　電気めっき条件：電流密度０．５９Ａ／ｄｍ2、時間０．７３秒 (Example 4)
A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
<Conditions for Forming Roughened Particles>
Plating solution composition: 11 g/L Cu, 50 g/L sulfuric acid, 3 ppm tungsten (from sodium tungstate dihydrate)
Electroplating conditions: current density 38.8 A/dm 2 , time 1.27 seconds <Conditions for forming cover plating layer>
Electroplating conditions: current density 8.2 A/dm 2 , time 1.44 seconds <Conditions for Ni—Zn layer formation>
Electroplating conditions: current density 0.59 A/dm 2 , time 0.73 seconds
（実施例５）
　厚さ１２μｍの圧延銅箔（ＪＸ金属株式会社製ＨＧ箔）を準備し、一方の面を脱脂及び酸洗した後、表面処理層として粗化処理層、耐熱処理層（Ｎｉ－Ｚｎ層）、クロメート処理層及びシランカップリング処理層を順次形成することによって表面処理銅箔を得た。各処理層の形成条件は次の通りとした。
（１）粗化処理層
＜粗化粒子の形成条件＞
　めっき液組成：１２ｇ／ＬのＣｕ、５０ｇ／Ｌの硫酸、５ｐｐｍのタングステン（タングステン酸ナトリウム２水和物由来）
　めっき液温度：２７℃
　電気めっき条件：電流密度４８．３Ａ／ｄｍ2、時間０．８１秒
　電気めっき処理回数：２回 (Example 5)
A rolled copper foil (HG foil manufactured by JX Metals Co., Ltd.) with a thickness of 12 μm is prepared, one side is degreased and pickled, and then a roughened layer and a heat-resistant layer (Ni—Zn layer) are formed as surface treatment layers. A surface-treated copper foil was obtained by sequentially forming a chromate-treated layer and a silane coupling-treated layer. The conditions for forming each treated layer were as follows.
(1) Roughened layer <Conditions for forming roughened particles>
Plating solution composition: 12 g/L Cu, 50 g/L sulfuric acid, 5 ppm tungsten (from sodium tungstate dihydrate)
Plating solution temperature: 27°C
Electroplating conditions: current density 48.3 A/dm 2 , time 0.81 seconds Number of electroplating treatments: 2 times
＜かぶせめっき層の形成条件＞
　めっき液組成：２０ｇ／ＬのＣｕ、１００ｇ／Ｌの硫酸
　めっき液温度：５０℃
　電気めっき条件：電流密度１１．９Ａ／ｄｍ2、時間１．１５秒
　電気めっき処理回数：２回 <Conditions for Forming Cover Plating Layer>
Plating solution composition: 20 g/L Cu, 100 g/L sulfuric acid Plating solution temperature: 50°C
Electroplating conditions: current density 11.9 A/dm 2 , time 1.15 seconds Number of electroplating treatments: 2 times
（２）耐熱処理層
＜Ｎｉ－Ｚｎ層の形成条件＞
　めっき液組成：２３．５ｇ／ＬのＮｉ、４．５ｇ／ＬのＺｎ
　めっき液ｐＨ：３．６
　めっき液温度：４０℃
　電気めっき条件：電流密度１．０７Ａ／ｄｍ2、時間０．５９秒
　電気めっき処理回数：１回 (2) Heat-resistant layer <Conditions for forming Ni—Zn layer>
Plating solution composition: 23.5 g/L Ni, 4.5 g/L Zn
Plating solution pH: 3.6
Plating solution temperature: 40°C
Electroplating conditions: current density 1.07 A/dm 2 , time 0.59 seconds Number of electroplating treatments: 1 time
（３）クロメート処理層
＜電解クロメート処理層の形成条件＞
　クロメート液組成：３ｇ／ＬのＫ2Ｃｒ2Ｏ7、０．３３ｇ／ＬのＺｎ
　クロメート液ｐＨ：３．６５
　クロメート液温度：５５℃
　電解条件：電流密度１．９１Ａ／ｄｍ2、時間０．５９秒
　クロメート処理回数：２回 (3) Chromate-treated layer <Conditions for forming electrolytic chromate-treated layer>
Chromate liquid composition: 3 g/L K2Cr2O7 , 0.33 g/L Zn
Chromate solution pH: 3.65
Chromate liquid temperature: 55°C
Electrolysis conditions: current density 1.91 A/dm 2 , time 0.59 seconds Number of chromate treatments: 2 times
（４）シランカップリング処理層
　Ｎ－２－（アミノエチル）－３－アミノプロピルトリメトキシシランの１．２体積％水溶液を塗布し、乾燥させることでシランカップリング処理層を形成した。 (4) Silane Coupling Treated Layer A 1.2% by volume aqueous solution of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane was applied and dried to form a silane coupling treated layer.
（比較例１）
　実施例１で用いた圧延銅箔（表面処理を行っていない銅箔）を比較として用いた。 (Comparative example 1)
The rolled copper foil (copper foil without surface treatment) used in Example 1 was used for comparison.
（比較例２）
　以下の条件を変更したこと以外は実施例１と同様の条件で表面処理銅箔を得た。
＜粗化粒子の形成条件＞
　めっき液組成：１１ｇ／ＬのＣｕ、５０ｇ／Ｌの硫酸
　電気めっき条件：電流密度３８．８Ａ／ｄｍ2、時間１．２７秒
＜かぶせめっき層の形成条件＞
　電気めっき条件：電流密度８．２Ａ／ｄｍ2、時間１．４４秒
＜Ｎｉ－Ｚｎ層の形成条件＞
　電気めっき条件：電流密度０．５９Ａ／ｄｍ2、時間０．７３秒
＜電解クロメート処理層の形成条件＞
　電解条件：電流密度１．４２Ａ／ｄｍ2、時間０．７３秒 (Comparative example 2)
A surface-treated copper foil was obtained under the same conditions as in Example 1, except that the following conditions were changed.
<Conditions for Forming Roughened Particles>
Plating solution composition: 11 g/L of Cu, 50 g/L of sulfuric acid Electroplating conditions: current density of 38.8 A/dm 2 , time of 1.27 seconds <Conditions for forming overlying plating layer>
Electroplating conditions: current density 8.2 A/dm 2 , time 1.44 seconds <Conditions for Ni—Zn layer formation>
Electroplating conditions: current density 0.59 A/dm 2 , time 0.73 seconds <Conditions for forming electrolytic chromate treatment layer>
Electrolysis conditions: current density 1.42 A/dm 2 , time 0.73 seconds
　上記の実施例及び比較例で得られた表面処理銅箔又は銅箔について、下記の特性評価を行った。
＜Ｓｋ、Ｓｋｕ、Ｓｑ、Ｓａ及びＳｓｋ＞
　ＩＳＯ　２５１７８－２：２０１２に準拠し、オリンパス株式会社製のレーザー顕微鏡（ＬＥＸＴ　ＯＬＳ４０００）を用いて測定（画像撮影）を行なった。撮影した画像の解析は、オリンパス株式会社製のレーザー顕微鏡（ＬＥＸＴ　ＯＬＳ４１００）の解析ソフトを用いて行った。結果には、任意の５か所で測定及び解析した値の平均値を用いた。なお、測定時の温度は２３～２５℃とした。また、レーザー顕微鏡及び解析ソフトにおける主要な設定条件は下記の通りである。
　対物レンズ：ＭＰＬＡＰＯＮ５０ＸＬＥＸＴ（倍率：５０倍、開口数：０．９５、液浸タイプ：空気、機械的鏡筒長：∞、カバーガラス厚：０、視野数：ＦＮ１８）
　光学ズーム倍率：１倍
　走査モード：ＸＹＺ高精度（高さ分解能：６０ｎｍ、取込みデータの画素数：１０２４×１０２４）
　取込み画像サイズ［画素数］：横２５７μｍ×縦２５８μｍ［１０２４×１０２４］
（横方向に測定するため、評価長さとしては２５７μｍに相当）
　ＤＩＣ：オフ
　マルチレイヤー：オフ
　レーザー強度：１００
　オフセット：０
　コンフォーカルレベル：０
　ビーム径絞り：オフ
　画像平均：１回
　ノイズリダクション：オン
　輝度むら補正：オン
　光学的ノイズフィルタ：オン
　カットオフ：Ｐ１（Ｓｋ）測定時については、λｃ＝２００μｍ及びλｓ＝２μｍを適用し、λｆは適用無し。Ｐ２（Ｓｋ）、Ｓｋｕ、Ｓｑ、Ｓａ及びＳｓｋ測定時については、λｃ＝２００μｍを適用し、λｓ及びλｆは適用無し。
　フィルタ：ガウシアンフィルタ
　ノイズ除去：測定前処理
　表面(傾き)補正：実施
　明るさ：３０～５０の範囲になるように調整する
　明るさは測定対称の色調によって適宜設定すべき値である。上記の設定はＬ＊が－６９～－１０、ａ＊が２～３２、ｂ＊が２２１の表面処理銅箔の表面を測定する際に適切な値である。
　また、Ｓｋについては、上記式（１）にしたがってＳｋの変化率を算出した。
　なお、λｃフィルタはＩＳＯ　２５１７８－２：２０１２におけるＬフィルタに相当する。 The surface-treated copper foils or copper foils obtained in the above examples and comparative examples were evaluated for the following characteristics.
<Sk, Sku, Sq, Sa and Ssk>
In accordance with ISO 25178-2:2012, measurement (image photography) was performed using a laser microscope (LEXT OLS4000) manufactured by Olympus Corporation. The captured images were analyzed using analysis software for a laser microscope (LEXT OLS4100) manufactured by Olympus Corporation. The average value of the values measured and analyzed at any five locations was used as the result. The temperature during the measurement was 23 to 25°C. Main setting conditions for the laser microscope and analysis software are as follows.
Objective lens: MPLAPON50XLEXT (magnification: 50x, numerical aperture: 0.95, liquid immersion type: air, mechanical barrel length: ∞, cover glass thickness: 0, field number: FN18)
Optical zoom magnification: 1x Scanning mode: XYZ high precision (height resolution: 60 nm, number of pixels of captured data: 1024 x 1024)
Captured image size [Number of pixels]: Horizontal 257 μm × Vertical 258 μm [1024 × 1024]
(Since it is measured in the horizontal direction, it corresponds to 257 μm as an evaluation length)
DIC: Off Multilayer: Off Laser intensity: 100
Offset: 0
Confocal level: 0
Beam diameter aperture: OFF Image average: 1 time Noise reduction: ON Brightness unevenness correction: ON Optical noise filter: ON Cutoff: For P1 (Sk) measurement, λc = 200 µm and λs = 2 µm are applied, and λf is Not applicable. When measuring P2(Sk), Sku, Sq, Sa and Ssk, λc=200 μm is applied and λs and λf are not applied.
Filter: Gaussian filter Noise removal: Pre-measurement processing Surface (tilt) correction: Implemented Brightness: Adjust to be in the range of 30 to 50 Brightness should be appropriately set according to the color tone to be measured. The above settings are appropriate values when measuring the surface of a surface-treated copper foil with L* of -69 to -10, a* of 2 to 32, and b* of 221.
As for Sk, the rate of change of Sk was calculated according to the above formula (1).
Note that the λc filter corresponds to the L filter in ISO 25178-2:2012.
＜測定対象の色調の測定＞
　測定器としてＨｕｎｔｅｒＬａｂ社製のＭｉｎｉＳｃａｎ（登録商標）ＥＺ　Ｍｏｄｅｌ　４０００Ｌを用い、ＪＩＳ　Ｚ８７３０：２００９に準拠してＣＩＥ　Ｌ＊ａ＊ｂ＊表色系のＬ＊、ａ＊及びｂ＊の測定を行った。具体的には、上記の実施例及び比較例で得られた表面処理銅箔又は銅箔の測定対象面を測定器の感光部に押し当て、外から光が入らないようにしつつ測定した。また、Ｌ＊、ａ＊及びｂ＊の測定は、ＪＩＳ　Ｚ８７２２：２００９の幾何条件Ｃに基づいて行った。なお、測定器の主な条件は下記の通りである。
　光学系：ｄ／８°、積分球サイズ：６３．５ｍｍ、観察光源：Ｄ６５
　測定方式：反射
　照明径：２５．４ｍｍ
　測定径：２０．０ｍｍ
　測定波長・間隔：４００～７００ｎｍ・１０ｎｍ
　光源：パルスキセノンランプ・１発光／測定
　トレーサビリティ標準：ＣＩＥ　４４及びＡＳＴＭ　Ｅ２５９に基づく、米国標準技術研究所（ＮＩＳＴ）準拠校正
　標準観察者：１０°
　また、測定基準となる白色タイルは、下記の物体色のものを使用した。
　Ｄ６５／１０°にて測定した場合に、ＣＩＥ　ＸＹＺ表色系での値がＸ：８１．９０、Ｙ：８７．０２、Ｚ：９３．７６ <Measurement of color tone of measurement target>
Using HunterLab's MiniScan (registered trademark) EZ Model 4000L as a measuring instrument, L*, a* and b* of the CIE L*a*b* color system were measured in accordance with JIS Z8730:2009. . Specifically, the measurement target surface of the surface-treated copper foil or copper foil obtained in the above examples and comparative examples was pressed against the photosensitive part of the measuring device, and the measurement was performed while preventing light from entering from the outside. In addition, L*, a* and b* were measured based on geometric condition C of JIS Z8722:2009. The main conditions of the measuring instrument are as follows.
Optical system: d/8°, integrating sphere size: 63.5 mm, observation light source: D65
Measurement method: Reflection Illumination diameter: 25.4mm
Measurement diameter: 20.0mm
Measurement wavelength/interval: 400 to 700 nm/10 nm
Light source: pulsed xenon lamp, 1 emission/measurement Traceability standard: National Institute of Standards and Technology (NIST) compliant calibration based on CIE 44 and ASTM E259 Standard observer: 10°
In addition, the following object colors were used for the white tiles used as the measurement standard.
When measured at D65/10°, the values in the CIE XYZ color system are X: 81.90, Y: 87.02, Z: 93.76
＜ピール強度＞
　表面処理銅箔をポリイミド樹脂基材と貼り合わせた後、幅３ｍｍの回路をＭＤ方向（圧延銅箔の長手方向）に形成した。回路の形成は通常の方法に則って実施した。次に、回路（表面処理銅箔）を樹脂基材の表面に対して、５０ｍｍ／分の速度で９０°方向に、すなわち、樹脂基材の表面に対して鉛直上向きに、引き剥がすときの強さ（ＭＤ９０°ピール強度）をＪＩＳ　Ｃ６４７１：１９９５に準拠して測定した。測定は３回行い、その平均値をピール強度の結果とした。ピール強度は、０．５０ｋｇｆ／ｃｍ以上であれば、回路（表面処理銅箔）と樹脂基材との接着性が良好であるといえる。
　なお、比較例１の銅箔については、ポリイミド樹脂基材と貼り合わせることができなかったため、この評価は行わなかった。 <Peel strength>
After bonding the surface-treated copper foil to the polyimide resin substrate, a circuit with a width of 3 mm was formed in the MD direction (longitudinal direction of the rolled copper foil). Formation of the circuit was carried out according to the usual method. Next, the circuit (surface-treated copper foil) is peeled off from the surface of the resin base material at a speed of 50 mm/min in a 90° direction, that is, vertically upward with respect to the surface of the resin base material. The thickness (MD90° peel strength) was measured according to JIS C6471:1995. The measurement was performed three times, and the average value was taken as the result of the peel strength. If the peel strength is 0.50 kgf/cm or more, it can be said that the adhesion between the circuit (surface-treated copper foil) and the resin substrate is good.
This evaluation was not performed for the copper foil of Comparative Example 1 because it could not be attached to the polyimide resin substrate.
　上記の特性評価の結果を表１に示す。 Table 1 shows the results of the above characteristic evaluation.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示されるように、表面処理層のＳｋの変化率が２３．０～４５．０％の範囲内にある実施例１～５の表面処理銅箔はピール強度が高かった。
　一方、表面処理層のＳｋの変化率が所定の範囲外である比較例２の表面処理銅箔は、ピール強度が低かった。 As shown in Table 1, the peel strength of the surface-treated copper foils of Examples 1-5, in which the rate of change in Sk of the surface treatment layer was in the range of 23.0-45.0%, was high.
On the other hand, the surface-treated copper foil of Comparative Example 2, in which the rate of change in Sk of the surface-treated layer was outside the predetermined range, had low peel strength.
　以上の結果及びこれまで述べてきた本発明の実施形態の考察を参照すると、本発明の実施形態によれば、樹脂基材、特に高周波用途に好適な樹脂基材との接着性を高めることが可能な表面処理銅箔を提供することができる。また、本発明の実施形態によれば、樹脂基材、特に高周波用途に好適な樹脂基材と表面処理銅箔との間の接着性に優れた銅張積層板を提供することができる。さらに、本発明の実施形態によれば、樹脂基材、特に高周波用途に好適な樹脂基材と回路パターンとの間の接着性に優れたプリント配線板を提供することができる。 With reference to the above results and the discussion of the embodiments of the present invention described so far, according to the embodiments of the present invention, it is possible to increase the adhesion to resin substrates, particularly resin substrates suitable for high frequency applications. A surface-treated copper foil can be provided. Further, according to the embodiment of the present invention, it is possible to provide a copper-clad laminate having excellent adhesion between a resin substrate, particularly a resin substrate suitable for high frequency applications, and the surface-treated copper foil. Furthermore, according to the embodiment of the present invention, it is possible to provide a printed wiring board having excellent adhesiveness between a resin substrate, particularly a resin substrate suitable for high frequency applications, and a circuit pattern.
　１０　銅箔
　１１　凸部
　１２　凹部
　２０　粗化粒子
　３０　かぶせめっき層 REFERENCE SIGNS LIST 10 Copper foil 11 Convex portion 12 Concave portion 20 Roughened particles 30 Cover plating layer

Claims (10)

  1. 　銅箔と、前記銅箔の少なくとも一方の面に形成された表面処理層とを有し、
    　前記表面処理層は、下記式（１）で表されるＳｋの変化率が２３．０～４５．０％である表面処理銅箔。
    　Ｓｋの変化率＝（Ｐ２－Ｐ１）／Ｐ２×１００　・・・（１）
    　式中、Ｐ１は、カットオフ値λｓが２μｍのλｓフィルタを適用して算出されるＳｋであり、Ｐ２は、前記λｓフィルタを適用せずに算出されるＳｋである。     Having a copper foil and a surface treatment layer formed on at least one surface of the copper foil,
    The surface-treated layer is a surface-treated copper foil having a rate of change of Sk represented by the following formula (1) of 23.0 to 45.0%.
    Change rate of Sk=(P2-P1)/P2×100 (1)
    In the formula, P1 is Sk calculated by applying a λs filter with a cutoff value λs of 2 μm, and P2 is Sk calculated without applying the λs filter.
  2. 　前記Ｓｋの変化率が２３．０～４０．０％である、請求項１に記載の表面処理銅箔。 The surface-treated copper foil according to claim 1, wherein the rate of change of Sk is 23.0 to 40.0%.
  3. 　前記Ｓｋの変化率が２３．０～３６．０％である、請求項１に記載の表面処理銅箔。 The surface-treated copper foil according to claim 1, wherein the rate of change of Sk is 23.0 to 36.0%.
  4. 　前記表面処理層は、前記λｓフィルタを適用せずに算出されるＳｋｕが２．５０～４．５０である、請求項１～３のいずれか一項に記載の表面処理銅箔。 The surface-treated copper foil according to any one of claims 1 to 3, wherein the surface-treated layer has an Sku of 2.50 to 4.50 calculated without applying the λs filter.
  5. 　前記Ｓｋｕが２．９０～４．１０である、請求項４に記載の表面処理銅箔。 The surface-treated copper foil according to claim 4, wherein the Sku is 2.90 to 4.10.
  6. 　前記表面処理層は、前記λｓフィルタを適用せずに算出されるＳｑが０．２０～０．６０μｍである、請求項１～５のいずれか一項に記載の表面処理銅箔。 The surface-treated copper foil according to any one of claims 1 to 5, wherein the surface-treated layer has an Sq of 0.20 to 0.60 µm calculated without applying the λs filter.
  7. 　前記表面処理層は、前記λｓフィルタを適用せずに算出されるＳａが０．２０～０．４０μｍである、請求項１～６のいずれか一項に記載の表面処理銅箔。 The surface-treated copper foil according to any one of claims 1 to 6, wherein the surface-treated layer has an Sa calculated without applying the λs filter of 0.20 to 0.40 µm.
  8. 　前記表面処理層は粗化処理層を含有する、請求項１～７のいずれか一項に記載の表面処理銅箔。 The surface-treated copper foil according to any one of claims 1 to 7, wherein the surface treatment layer contains a roughening treatment layer.
  9. 　請求項１～８のいずれか一項に記載の表面処理銅箔と、前記表面処理銅箔の前記表面処理層に接着された樹脂基材とを備える銅張積層板。 A copper-clad laminate comprising the surface-treated copper foil according to any one of claims 1 to 8 and a resin substrate adhered to the surface treatment layer of the surface-treated copper foil.
  10. 　請求項９に記載の銅張積層板の前記表面処理銅箔をエッチングして形成された回路パターンを備えるプリント配線板。 A printed wiring board comprising a circuit pattern formed by etching the surface-treated copper foil of the copper-clad laminate according to claim 9.
PCT/JP2022/001220 2021-07-09 2022-01-14 Surface-treated copper foil, copper-clad laminate plate, and printed wiring board WO2023281777A1 (en)

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WO2021117339A1 (en) * 2019-12-13 2021-06-17 Ｊｘ金属株式会社 Surface-treated copper foil, copper-clad laminate plate, and printed wiring board

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