TW202134482A - Roughened copper foil, carrier-attached copper foil, copper-clad laminate, and printed wiring board - Google Patents

Abstract

Provided is a roughened copper foil capable of achieving both excellent high-frequency characteristics and high shear strength from processing of a copper-clad laminate to production of a printed wiring board. This roughened copper foil has a roughened surface on at least one side thereof. The roughened surface has an interface expansion area ratio Sdr of 0.50-7.00%, said interface expansion area ratio being measured in accordance with ISO 25178, under conditions of an S-filter cutoff wavelength of 0.55 [mu]m and an L-filter cutoff wavelength of 10 [mu]m. This roughened copper foil has a peak density Spd of 2.00*104 mm-2 to 3.30*104 mm-2, said peak density being measured in accordance with ISO 25178, under conditions of an S-filter cutoff wavelength of 3.0 [mu]m and an L-filter cutoff wavelength of 10 [mu]m.

Description

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

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

In recent years, the MSAP (modified semi-additive method) method has been widely adopted as a manufacturing method of printed wiring boards suitable for the miniaturization of circuits. The MSAP method is a method suitable for forming extremely fine circuits. In order to activate this feature, it is performed using copper foil with a carrier. For example, as shown in Figures 1 and 2, an ultra-thin copper foil 10 is placed on a base substrate 11a on an insulating resin substrate 11 equipped with a lower circuit 11b, using a prepreg 12 and a coating layer 13, and pressure-tightly bonded ( Process (a)), after peeling off the carrier (not shown), perforate through a laser as needed to form a through hole 14 (process (b)). Then, after applying electroless copper plating 15 (process (c)), through exposure and development using a dry film 16, masking with a specific pattern (process (d)), applying electrical copper plating 17 (process (e)) ). After the dry film 16 is removed to form the wiring portion 17a (process (f)), the adjacent wiring portions 17a and 17b need not be ultra-thin copper foil, etc., and the entire thickness is removed by etching (process ( g)), the wiring 18 formed in a specific pattern. Here, in order to improve the physical adhesion between the circuit and the substrate, the surface of the ultra-thin copper foil 10 is generally roughened.

In fact, several copper foils with a carrier have been proposed which are excellent in the formation of fine circuits by the MSAP method. For example, in Patent Document 1 (International Publication No. 2016/117587), it is disclosed that the average distance between the peaks of the surface on the side with the peeling layer is 20 μm or less, and the maximum height difference between the peeling layer and the surface on the opposite side is 1.0 Copper foil with carrier for ultra-thin copper foils of μm or less, depending on the relevant form, can achieve both fine circuit formation and laser processability. In addition, Patent Document 2 (Japanese Patent Application Laid-Open No. 2018-26590) discloses that for the purpose of improving the formability of fine circuits, the ratio of the maximum peak height Sp of ISO25178 on the side surface of the ultra-thin copper layer to the height of the protruding peak Spk Sp/ Spk is 3.271 or more and 10.739 or less copper foil with carrier.

However, with the high-performance of portable electronic devices in recent years, the high-speed processing of a large amount of information and the high-frequency of signals have demanded printed wiring boards suitable for high-frequency applications. In such a high-frequency printed wiring board, in order to transmit high-frequency signals without degrading quality, it is desirable to reduce the transmission loss. Although the printed wiring board is equipped with copper foil processed in the wiring pattern and an insulating resin substrate, the transmission loss is mainly caused by the conductor loss of the copper foil and the dielectric loss caused by the insulating resin substrate.

This part is known as a roughened copper foil for the purpose of reducing transmission loss. For example, Patent Document 3 (Japanese Patent No. 6462961) discloses a surface-treated copper foil laminated in the order of a roughening treatment layer, an anti-rust treatment layer, and a silane coupling layer on at least one side of the copper foil. The spread area ratio Sdr of the interface measured from the surface of the silane coupling layer is 8% or more and 140% or less, the secondary average square root surface slope Sdq is 25° or more and 70° or less, and the aspect ratio Str of the surface properties is 0.25 or more and 0.79 or less . According to the relevant surface treatment of copper foil, it is possible to manufacture printed wiring boards with low transmission loss of high-frequency electrical signals and excellent adhesion during reflow soldering. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] International Patent Publication No. 2016/117587 [Patent Document 2] Japanese Patent Application Publication No. 2018-26590 [Patent Document 3] Japanese Patent No. 6462961

As described above, from the viewpoint of high-frequency transmission, there is a demand for copper foil with less transmission loss (that is, copper foil with excellent high-frequency characteristics) as a material for forming circuit wiring for circulating signals. Through the smoothing of copper foil and the miniaturization of roughened particles, although transmission loss can be suppressed, the physical adhesion between copper foil and substrate resin, etc., will decrease.

Now, one of the physical adhesion indicators between the circuit and the substrate is the share strength. In order to improve the physical adhesion between the circuit and the substrate (hereinafter, simply referred to as circuit adhesion), it is necessary to change The shear strength is maintained above a certain level. However, in order to ensure the shear strength above a certain level, the roughened particles of the copper foil have to be made larger, and there is a problem that it is difficult to achieve both high-frequency characteristics and circuit adhesion. In this part, as described above, Patent Document 3 discloses a surface-treated copper foil that achieves both high-frequency characteristics and circuit adhesion. However, in order to obtain better high-frequency characteristics, when using a smoother copper foil , It is also required to ensure circuit tightness.

The inventors of the present invention found that in the current roughened copper foil, it was found that the surface profile of the copper clad laminate was controlled in a specific range by setting the spread area ratio of the interface Sdr and the peak apex density Spd specified in ISO25178. The processing and the manufacture of printed wiring boards can take into account both excellent high frequency characteristics and high shear strength.

Therefore, the object of the present invention is to provide a roughened copper foil that can achieve both excellent high frequency characteristics and high shear strength in the processing of copper clad laminates and in the manufacture of printed wiring boards.

According to one aspect of the present invention, it is provided on at least one side of a roughened copper foil with a roughened surface. The roughened surface is based on ISO25178, the cut-off wavelength of the S filter is 0.55μm and the L filter is formed. The spread area ratio Sdr of the interface measured under the condition of a cutoff wavelength of 10μm is 0.50% to 7.00%, according to ISO25178, under the conditions of a cutoff wavelength of 3.0μm for S filter and 10μm for L filter The measured peak apex density Spd is 2.00×10 ⁴ mm ^-2 or more and 3.30×10 ⁴ mm ^-2 or less roughened copper foil.

According to another aspect of the present invention, there is provided a carrier-attached copper with a carrier, and a release layer provided on the carrier, and the roughened copper foil provided on the release layer so that the roughening process faces the outside Foil.

According to another aspect of the present invention, there is provided a copper-clad laminate having the aforementioned roughened copper foil.

According to another aspect of the present invention, a printed wiring board provided with the aforementioned roughened copper foil is provided.

definition

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

In this specification, the "expansion area ratio Sdr of the interface" is a parameter indicating how much the expansion area (surface area) of the defined area measured in accordance with ISO25178 is increased for the area of the defined area. However, in this specification, the spread area ratio Sdr of the interface is expressed as the increase in surface area (%). The smaller this value is, the closer the display is to a flat surface shape, and the Sdr of a completely flat surface becomes 0%. On the other hand, the larger the value, the more uneven the surface shape. For example, when the Sdr of the surface is 40%, the surface shows a 40% increase in surface area from a completely flat surface.

In this manual, "peak apex density Spd" is a parameter indicating the number of peak vertices per unit area measured in accordance with ISO25178, and only the peak apex that is larger than 5% of the maximum amplitude of the contour surface is calculated. When this value is large, the number of points of contact with other objects will be displayed.

In this manual, "surface load curve" (hereinafter, simply referred to as "load curve") is a curve representing the height of the load area ratio measured in accordance with ISO25178 from 0% to 100%. The load area ratio is shown in Fig. 3, and is a parameter representing the area of an area above a certain height c. The load area ratio of height c is equivalent to Smr(c) in Fig. 3. As shown in Figure 4, the load area ratio is 0% along the load curve, and the difference in load area ratio is 40%. The broken line of the load curve is moved from the load area ratio of 0% to minimize the inclination of the broken line. The position is called the central part of the load curve. For this central part, the straight line that minimizes the sum of the squares of the deviations in the vertical axis direction is called an equivalent straight line. The part in the range of height from 0% to 100% of the load area ratio of the equivalent straight line is called the core part. The part higher than the core part is called the protruding peak, and the part lower than the core part is called the protruding valley.

In this manual, the "level difference Sk of the core part" is the value of the minimum height subtracted from the maximum height of the core part measured in accordance with ISO25178. As shown in Figure 4, the load area ratio through the equivalent straight line is 0% and 100% The parameter calculated by the height difference.

In this manual, "maximum height Sz" is a parameter indicating the distance from the highest point to the lowest point of the surface measured in accordance with ISO25178.

In this specification, the "aspect ratio Str of surface properties" refers to the parameters of isotropy or even anisotropy of surface properties measured in accordance with ISO25178. Str is in the range of 0 to 1. Generally, Str>0.5 shows strong isotropy, on the contrary, Str<0.3 shows strong anisotropy.

The spread area ratio of the interface Sdr, the peak apex density Spd, the core level difference Sk, the maximum height Sz, and the aspect ratio Str of the surface properties can be a specific measurement area of the roughened surface (e.g. 16384μm ² quadratic area) The surface profile was measured by a commercially available laser microscope and calculated separately. In this manual, the values of the spread area ratio of the interface Sdr, the level difference Sk of the core part, the maximum height Sz, and the aspect ratio Str of the surface properties are at the cut-off wavelength of 0.55μm by the S filter and the cut-off wavelength by the L filter. The value measured under the condition of 10μm. In this specification, the value of the peak apex density Spd system is a value measured under the conditions of a cut-off wavelength of 3 μm by the S filter and a cut-off wavelength of 10 μm by the L filter.

In this specification, the "electrode surface" of the carrier refers to the surface on the side in contact with the cathode when the carrier is made.

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

Roughened copper foil The copper foil formed by the present invention is a roughened copper foil. This roughened copper foil is on at least one side and has a roughened surface. The spread area ratio Sdr of the roughened surface system interface is 0.50% or more and 7.00% or less, and the peak apex density Spd is 2.00×10 ⁴ mm ^-2 or more and 3.30×10 ⁴ mm ^-2 or less. In this way, in the roughened copper foil, the spread area ratio of the interface Sdr and the peak apex density Spd are assigned to the surface profile controlled in each specific range for the processing of the copper clad laminate and the manufacture of the printed wiring board In the medium, both excellent high frequency characteristics and high shear strength can be achieved.

Excellent high-frequency characteristics and high shear strength are originally difficult to balance. As mentioned above, in order to obtain excellent high-frequency characteristics, generally speaking, it is required to reduce the roughness particles. On the other hand, to improve the circuit The shear strength, generally speaking, requires that the roughened particles become larger. Therefore, the shear strength is not simply proportional to the specific surface area or roughness height used for evaluation in the past, and it is difficult to control it. In this regard, the present inventors have found that in order to obtain the correlation of physical properties such as high-frequency characteristics and shear strength, it is effective to evaluate the spread area ratio of the combined interface Sdr and the peak apex density Spd. Specifically, it was found that the edge control the expansion area ratio of the interface Sdr to a very small range, which makes the surface of the roughened copper foil significantly smoother. By controlling the peak apex density Spd to a small value, although it is a high frequency A fine surface with excellent characteristics can also obtain a suitable roughened copper foil with protrusion height, protrusion density, and specific surface area that can ensure high shear strength. That is, first, when the spread area ratio Sdr of the interface is controlled to a specific range, when the size of the roughened particles on the surface of the roughened copper foil is large, the number of extremely small particles that cannot provide shear strength increases. , The apex density Spd of this peak tends to increase. In this regard, according to the roughened copper foil of the present invention, roughened particles of an appropriate size imparting shear strength are attached to the roughened surface without unevenness, even if the expansion area ratio of the interface is controlled to a very small range. At this time, the apex density Spd of this peak can also be controlled to a small value. In this way, when the copper foil is roughened according to the present invention, excellent high-frequency characteristics and high shear strength (moreover, high circuit adhesion from the viewpoint of shear strength) can be realized.

From the viewpoint of achieving excellent high frequency characteristics and high shear strength in a good balance, the spread area ratio Sdr of the roughened surface of the roughened copper foil is 0.50% or more and 7.00% or less, preferably 0.50% or more 4.00% or less, more preferably 0.50% or more and 2.00% or less. Within this range, even if it is a fine surface (roughened height) with excellent high-frequency characteristics, it can ensure a sufficient adhesion area to the laminated resin during the manufacture of copper-clad laminates and even printed wiring boards, and improve the shear strength. The view of circuit adhesion.

From the viewpoint of achieving excellent high-frequency characteristics and high shear strength with a good balance, the peak density Spd of the roughened surface of the roughened copper foil is 2.00×10 ⁴ mm ^-2 or more 3.30×10 ⁴ mm ^-2 Below, it is preferably 2.00×10 ⁴ mm ^-2 or more and 2.80×10 ⁴ mm ^-2 or less, and more preferably 2.00×10 ⁴ mm ^-2 or more and 2.45×10 ⁴ mm ^-2 or less. Within this range, it is possible to ensure sufficient adhesion points to the laminated resin during the manufacture of the copper-clad laminate and even the printed wiring board, and at the same time, the transmission path of the high-frequency signal can be suppressed from lengthening, and the transmission loss can be reduced.

For the roughened copper foil, the ratio of the spread area of the interface of the roughened surface to the peak density Spd (mm ^-2 ) of the peak of Sdr (%) Spd/Sdr is preferably 7000 or more, preferably 8000 or more and 15000 or less, More preferably, it is 9000 or more and 12000 or less. For this reason, by controlling the ratio between the spread area of the interface Sdr and the peak apex density Spd within the above range, the roughened surface can become roughened particles of an appropriate size that imparts shear strength and adhere to the roughened surface. The structure of the treatment surface makes it easy for the roughened particles constituting the surface to be roughened into the resin evenly. As a result, it has excellent high-frequency characteristics and can ensure high shear strength.

The roughened copper foil is preferably Sz×Spd of the product of the maximum height Sz (μm) of the roughened surface and the peak apex density Spd (mm ^-2 ) of 20000 or more, preferably 24000 or more and 65000 or less, more Preferably, it is above 25,000 and below 35,000. For the roughened copper foil, while keeping the spread area ratio Sdr within the above range, by controlling Sz×Spd in this range, a high balance can be ensured to ensure the smoothness of the roughened copper foil, and the presence of high density on the roughened surface The state of larger protrusions (roughened particles) maintains excellent high-frequency characteristics and improves the adhesion to the resin. As a result, it has excellent high-frequency characteristics and can ensure high shear strength. In addition, from the viewpoint of achieving a finer surface with more excellent high-frequency characteristics, the maximum height Sz of the roughened surface of the roughened copper foil is preferably 1.3 μm or less, preferably 0.1 μm or more and 0.9 μm or less, and more It is preferably 0.4 μm or more and 0.9 μm or less.

The aspect ratio Str of the roughened surface of the roughened copper foil is preferably 0.90 or less, preferably 0.30 or more and 0.90 or less, and more preferably 0.50 or more and 0.90 or less. Within such a range, even if there is an appropriate fluctuation in the adhesion with the resin on the roughened surface, there is also an isotropy in favor of high-frequency characteristics. As a result, high shear strength can be ensured, and excellent high-frequency characteristics can be achieved.

From the viewpoint of achieving excellent high-frequency characteristics and high shear strength in a good balance, the step difference Sk of the core part of the roughened surface of the roughened copper foil is preferably 0.05 μm or more and 0.30 μm or less, preferably 0.05 μm or more and 0.20 μm or less, more preferably 0.05 μm or more and 0.15 μm or less. Within this range, even if it is a fine surface (roughened height) with excellent high-frequency characteristics, the roughened particles constituting the roughened surface are evenly trapped in the resin, and the adhesion to the resin is further improved. That is, when there is unevenness in the roughening treatment, the unevenness becomes a protruding peak portion of the roughening treatment surface. However, such unevenness (protruding peaks) is an improvement in circuit adhesion from the viewpoint that it is difficult to impart shear strength. In this part, the maximum height Sz used in previous evaluations is the parameters including the protruding peaks. For this reason, according to such parameters, it is easy to increase the roughness height when the circuit adhesion is improved, and as a result, the high-frequency characteristics tend to be degraded. In contrast, the level difference Sk of the core part is a parameter that does not include the protruding peak part as described above. Therefore, the step difference Sk of the core part is used as an evaluation index to improve the adhesion with the resin, and as a result, the increase in the roughness height can be suppressed.

Although the thickness of the roughened copper foil is not particularly limited, it is preferably 0.1 μm or more and 35 μm or less, preferably 0.5 μm or more and 5.0 μm or less, and more preferably 1.0 μm or more and 3.0 μm or less. However, the roughening treatment of copper foil is not limited to the surface of ordinary copper foil. For roughening treatment, the surface of the copper foil with carrier copper foil may be roughened. Here, the thickness of the roughened copper foil does not include the thickness of the height of the roughened particles formed on the surface of the roughened surface (the thickness of the copper foil itself constituting the roughened copper foil). There are cases where the copper foil having a thickness in the above-mentioned range is called an ultra-thin copper foil.

The roughened copper foil is on at least one side and has a roughened surface. That is, the roughened copper foil is on both sides and may have a roughened surface, and only one side may have a roughened surface. The roughening treatment surface typically has a plurality of roughening particles (protrusions), and it is preferable that the plurality of roughening particles are each made of copper particles. The copper particles can be made of metallic copper or copper alloys.

The roughening treatment to form the roughened surface is on the copper foil, and the roughened particles are formed with copper or copper alloy, which can be preferably performed. For example, according to the plating method through at least two types of plating processes including a sintered plating process in which fine copper particles are deposited and deposited on the copper foil, and a coating plating process to prevent the fine copper particles from falling off. Roughening treatment is better. At this time, the sintering plating process consists of a copper sulfate solution containing a copper concentration of 5g/L or more and 20g/L or less and a sulfuric acid concentration of 180g/L or more and 240g/L or less, and containing 20ppm or more and 29ppm or less of carboxybenzotriazole (CBTA) , Electrodeposition is better. In addition, the coating plating process is performed in a copper sulfate solution containing a copper concentration of 50g/L or more and 100g/L or less and a sulfuric acid concentration of 200g/L or more and 250g/L or less, at a temperature of 40°C or higher and 60°C or less, at a temperature of 2A/ dm ² or more and 4A/dm ² or less, it is better to carry out electrodeposition. In this regard, in the sintering plating process, adding carboxybenzotriazole within the above concentration range to the electroplating solution, maintaining the etching properties close to that of pure copper, for roughening copper foil, it can be used to control the spread area ratio Sdr In a very small range, the roughening particles of the appropriate size that give the shear strength are attached to the structure of the roughening treatment surface without unevenness, and the peak apex density Spd can also be controlled to a small value. That is, suitable protrusions satisfying the above surface parameters can be easily formed on the treated surface. More and more. In the sintered plating process and the covered plating process, the current density is reduced compared to the previous method for electrodeposition, and the appropriate protrusions that meet the above surface parameters can be easily formed on the processed surface.

As desired, the roughened copper foil system can be rust-proofed, and a rust-proof treatment layer may be formed. The anti-rust treatment preferably includes the plating treatment using zinc. The zinc plating treatment can be either a zinc plating treatment or a zinc alloy plating treatment. The zinc alloy plating treatment is preferably a zinc-nickel alloy treatment. The zinc-nickel alloy treatment may be a plating treatment including at least Ni and Zn, and may also include other elements such as Sn, Cr, and Co. The Ni/Zn adhesion ratio of zinc-nickel alloy plating is preferably 1.2 or more and 10 or less by mass ratio, preferably 2 or more and 7 or less, and more preferably 2.7 or more and 4 or less. In addition, the anti-rust treatment may further include chromate treatment. This chromate treatment is preferably performed on the surface of the plating containing zinc after the zinc plating treatment is used. In this way, the rust resistance can be further improved. The most preferred anti-rust treatment is a combination of zinc-nickel alloy plating treatment and subsequent chromate treatment.

If desired, the roughened copper foil is on the surface, and it can be treated with a silane coupling agent to form a silane coupling agent layer. As a result, the moisture resistance, chemical resistance, and adhesion of adhesives, etc., can be improved. The silane coupling agent layer is formed by appropriately diluting the silane coupling agent, coating, and drying. As an example of the silane coupling agent, epoxy functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc., or 3-amines Trimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy) Amino functional silane coupling agent such as propyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, or 3-hydrothiopropyltrimethoxysilane Hydrogen sulfide functional silane coupling agent such as silane or olefin functional silane coupling agent such as vinyl trimethoxysilane, vinyl phenyl trimethoxy silane, or 3-methylpropoxypropyl trimethoxy Acrylic functional silane coupling agent such as silane, or imidazole functional silane coupling agent such as imidazole silane, or triazine functional silane coupling agent such as triazine silane, etc.

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

Copper foil with carrier As described above, the roughened copper foil of the present invention may be provided in the form of a copper foil with a carrier. That is, according to a preferred aspect of the present invention, there is provided a carrier-coated copper with a carrier, and a release layer provided on the carrier, and the above-mentioned roughened copper foil provided on the release layer so that the roughening process faces the outside Foil. Of course, the copper foil with a carrier can adopt a well-known layer structure in addition to the roughened copper foil of the present invention.

The carrier system supports the roughening treatment of the copper foil to improve the operability of the support. A typical carrier system includes a metal layer. As an example of such a carrier, aluminum foil, copper foil, stainless steel (SUS) foil, resin film or glass coated with a metal such as copper on the surface can be cited. Preferably it is copper foil. Although the copper foil system may be any of rolled copper foil and electrolytic copper foil, electrolytic copper foil is preferable. The thickness of the carrier is typically 250 μm or less, preferably 9 μm or more and 200 μm or less.

The surface of the release layer side of the carrier is preferably smooth. That is, in the manufacturing process of the carrier-attached copper foil, an ultra-thin copper foil (before the roughening treatment) is formed on the surface of the carrier on the side of the release layer. When the roughened copper foil of the present invention is used in the form of a carrier-attached copper foil, the roughened copper foil is obtained by applying roughening treatment to such an extremely thin copper foil. Therefore, by smoothing the surface of the peeling layer side of the carrier, the surface of the outer side of the ultra-thin copper foil can also be smoothed. The smooth surface of the ultra-thin copper foil is roughened, which is easy to achieve within the above-mentioned specific range. The unfolded area of the interface is worse than the level of Sdr and the core part, the roughened surface of Sk. In order to make the surface of the peeling layer of the carrier smooth, for example, the carrier is used on the cathode surface of electrolytic foil, and it is polished with a specific model of grinding wheel to adjust the surface roughness. That is, the surface profile of the cathode adjusted in this way is transferred to the electrode surface of the carrier. On the electrode surface of the carrier, an ultra-thin copper foil is formed via the peeling layer. The smooth surface state of the roughened surface. Preferably, the model of the grinding wheel is #2000 above#3000 or below, preferably #2000 above#2500 or below. In addition, from the viewpoint of smoothing the ultra-thin copper foil and making it easier to control the developed area of the roughened copper foil in the above range than Sdr, the conditions for electrolysis of the foil carrier are the use of the following additives Conditions are better. That is, use the copper concentration to be 60g/L or more and 100g/L or less, and the sulfuric acid concentration to be 50g/L or more and 150g/L or less, as an additive, so that the concentration of the active sulfur compound sulfonate is 5mg/L or more and 1g /L, the concentration of the quaternary ammonium salt polymer with ring structure is 5mg/L above 500mg/L, and the chlorine concentration is adjusted to 10mg/L above 100mg/L in sulfuric acid copper electrolyte. Using DSA (Dimensional Stability Anode), the liquid temperature is above 40°C and below 60°C, and the current density is ^{above 30A/dm 2 and} below 100A/dm ² for electrolysis, which can better obtain electrolytic copper foil with a smoother surface. Here, examples of sulfonates of active sulfur compounds used as additives include 3-hydrosulfan-1-propane sulfonate, and bis(3-sulfopropyl)diphenyl sulfide. As an example of a quaternary ammonium salt polymer having a cyclic structure, diallyldimethylammonium chloride polymer and the like can be cited.

The peeling layer weakens the peeling strength of the carrier, guarantees the stability of the strength, and has a functional layer that inhibits mutual diffusion between the carrier and the copper foil during high-temperature press molding. The peeling layer is generally formed on one side of the carrier, but it may be formed on both sides. The peeling layer may be any one of an organic peeling layer and an inorganic peeling layer. As examples of organic components used in the organic release layer, nitrogen-containing organic compounds, sulfur-containing organic compounds, carboxylic acids, and the like can be cited. As examples of nitrogen-containing organic compounds, triazole compounds, imidazole compounds, etc. can be cited. Among them, the triazole compound is preferably a part that is easy to peel off. Examples of triazole compounds include 1,2,3-benzotriazole, carboxybenzotriazole, N',N'-bis(benzotriazolylmethyl)urea, 1H-1,2 ,4-Triazole and 3-amino-1H-1,2,4-triazole, etc. Examples of sulfur-containing organic compounds include hydrosulfanyl benzothiazole, trimer thiocyanate, 2-benzimidazole thiol acid, and the like. As an example of carboxylic acid, monocarboxylic acid, dicarboxylic acid, etc. are mentioned. As an example of the inorganic component used in the inorganic peeling layer, Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, chromate treatment film, etc. can be cited. However, the formation of the peeling layer may be performed on at least one surface of the carrier, contacting the solution containing the peeling layer component, and fixing the peeling layer component to the surface of the carrier. When the carrier is brought into contact with the solution containing the peeling layer component, the contact may be performed by dipping the solution containing the peeling layer component, spraying the solution containing the peeling layer component, or flowing down the solution containing the peeling layer component. In addition, a method of forming a film of the components of the peeling layer by a vapor deposition method such as vapor deposition or sputtering can be used. In addition, the fixing of the surface of the carrier of the release layer component may be carried out by adsorption or drying of the solution containing the release layer component, electrodeposition of the release layer component in the solution containing the release layer component, or the like. The thickness of the release layer is typically 1 nm or more and 1 μm or less, preferably 5 nm or more and 500 nm or less.

As desired, other functional layers may be provided between the peeling layer and the carrier and/or the roughened copper foil. As an example of such other functional layers, a supplementary metal layer can be cited. The auxiliary metal layer is preferably made of nickel and/or cobalt. By forming such a supplementary metal layer on the surface side of the carrier and/or the surface side of the roughened copper foil, the mutual diffusion between the carrier and the copper foil can be suppressed during high temperature or long-term hot pressing, and the carrier is guaranteed The stability of the peeling strength. The thickness of the auxiliary metal layer is preferably 0.001 μm or more and 3 μm or less.

Copper Clad Laminate The roughened copper foil of the present invention is preferably used in the production of copper clad laminates for printed wiring boards. That is, according to a preferred aspect of the present invention, a copper-clad laminate provided with the above-mentioned roughened copper foil is provided. By using the roughened copper foil of the present invention, in the processing of copper clad laminates, both excellent high frequency characteristics and high shear strength can be achieved. This copper clad laminate is provided with the roughened copper foil of the present invention and a resin layer provided in close contact with the roughened surface of the roughened copper foil. The roughened copper foil can be set on one side of the resin layer or on both sides. The resin layer contains resin, and preferably contains insulating resin. The resin layer is preferably a prepreg and/or resin sheet. Pre-impregnated system is the general term for composite materials impregnated with synthetic resin on synthetic resin plates, glass plates, glass woven fabrics, glass non-woven fabrics, paper, etc. Preferred examples of insulating resins include epoxy resins, cyanate resins, bismaleic anhydride imidotriazine resins (BT resins), polyphenylene ether resins, phenol resins, and the like. In addition, examples of insulating resins constituting the resin sheet include insulating resins such as epoxy resin, polyimide resin, and polyester resin. In addition, the resin layer may contain filler particles made of various inorganic particles such as silica, alumina, etc., from the viewpoint of improving insulation properties. Although the thickness of the resin layer is not particularly limited, it is preferably 1 μm or more and 1000 μm or less, preferably 2 μm or more and 400 μm or less, and more preferably 3 μm or more and 200 μm or less. The resin layer can be composed of plural layers. A resin layer such as a prepreg and/or a resin sheet is coated with a resin layer on the surface of the copper foil in advance, and may be provided on the roughened copper foil.

Printed wiring board The roughened copper foil of the present invention is preferably used in the production of printed wiring boards. That is, according to a preferred aspect of the present invention, a printed wiring board provided with the above-mentioned roughened copper foil is provided. By using the roughened copper foil of the present invention, in the manufacture of printed wiring boards, both excellent high frequency characteristics and high shear strength can be achieved. The printed wiring board of this form is comprised by the layer structure which laminated|stacked the resin layer and the copper layer. The copper layer is derived from the roughened copper foil layer of the present invention. Also, as for the resin layer, the copper-clad laminate is as described above. In any case, the printed wiring board can adopt a well-known layer structure in addition to the roughened copper foil of the present invention. As a specific example of a printed wiring board, one or both sides of a prepreg can be printed on one or both sides of a laminate that is hardened by adhering the roughened copper foil of the present invention to form a circuit. Wiring boards, or multi-layer printed wiring boards such as these. In addition, as other specific examples, the roughened copper foil of the present invention is formed on the resin film, and the flexible printed wiring board, COF, TAB tape, etc. of the circuit are formed. As another specific example, the roughened copper foil of the present invention can be used to form a resin-coated copper foil (RCC) coated with the above resin layer, and the resin layer is used as an insulating adhesive material and laminated on the above After the substrate is printed, the roughened copper foil is used as all or a part of the wiring layer, and the multilayer wiring board of the circuit is formed by the modified semi-additive method (MSAP) method and the erasing method, or the roughened copper foil is removed, The multilayer wiring board that forms the circuit by the partial additive method alternately repeats the laminate of the resin copper foil on the semiconductor integrated circuit and the direct laminate wafer for the circuit formation. As a more developed specific example, the antenna element formed by laminating the above-mentioned resin-coated copper foil on a substrate circuit, laminating it on glass or resin film via an adhesive layer, and forming a pattern for a panel or display Electronic materials or electronic materials for window glass, electromagnetic wave shielding films, etc. coated with conductive adhesive on the roughened copper foil of the present invention. In particular, the printed wiring board with roughened copper foil of the present invention can be used as an antenna for automobiles, antennas for mobile phone base stations, high-performance servers, and collision prevention used in high frequency bands with signal frequencies above 10 GHz. High-frequency substrates used for radar and other purposes are appropriately used. In particular, the roughened copper foil of the present invention is suitable for the MSAP method. For example, when the circuit is formed by the MSAP method, the configuration shown in Figs. 1 and 2 can be adopted. [Example]

The present invention will be explained in more detail through the following examples.

Examples 1, 2, 4 and 7 A copper foil with a carrier with a roughened copper foil will be produced and evaluated as follows.

(1) Preparation of a carrier composition of the copper electrolyte, and the cathode shown below, and as DSA anodes (anode dimensional stability), a solution temperature of 50 ℃, a current density of 70A / dm ² Electrolysis, the thickness of 18μm Electrolytic copper foil is made as a carrier. At this time, as the cathode, use an electrode that grinds the surface with a #2000 grinding wheel to adjust the surface roughness. <Composition of copper electrolyte>-Copper concentration: 80g/L-Sulfuric acid concentration: 300g/L-Chlorine concentration: 30mg/L-Glue concentration: 5mg/L

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

(3) allowance formed metal layer to form a carrier organic release layer, the impregnation production of nickel concentration of 20g / L of solution was nickel sulfate, a liquid temperature of 45 ℃, pH3, a current density of 5A / dm condition ² of the Nickel with a thickness equivalent to 0.001μm adheres to the organic release layer. In this way, on the organic release layer, the nickel layer is formed as the auxiliary metal layer.

(4) The formation of ultra-thin copper foil The carrier forming the auxiliary metal layer is immersed in a copper solution of the following composition, and electrolyzed at a solution temperature of 50°C and a current density of 5A/dm ² or more and 30A/dm ² or less, and the thickness is 1.5 The ultra-thin copper foil of μm is formed on the auxiliary metal layer. <The composition of the solution>-Copper concentration: 60g/L-Sulfuric acid concentration: 200g/L

(5) Roughening treatment The surface of the ultra-thin copper foil formed in this way is roughened to form a roughened copper foil, thereby obtaining a copper foil with a carrier. This roughening treatment is composed of a sintering plating process in which fine copper particles are deposited on the extremely thin copper foil, and a coating plating process in order to prevent the fine copper particles from falling off. In the sintering and plating process, add carboxybenzotriazole (CBTA) with the concentration shown in Table 1 to an acid copper sulfate solution containing a copper concentration of 10g/L and a sulfuric acid concentration of 200g/L at a liquid temperature of 25°C, as shown in Table 1. Indicate the current density and roughen it. In the subsequent coating and plating process, an acid copper sulfate solution containing a copper concentration of 70 g/L and a sulfuric acid concentration of 240 g/L was used to perform electrodeposition under smooth plating conditions at a liquid temperature of 52° C. and a current density as shown in Table 1. At this time, the CBTA concentration and current density of the sintered plating process and the current density of the covered plating process were appropriately changed to those shown in Table 1, and various samples with different characteristics of the roughened surface were cut.

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

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

(8) Evaluation For the thus obtained carrier-attached copper foil, various characteristics were evaluated as follows.

(8a) The surface quality parameters of the roughened surface were measured by surface roughness analysis using a laser microscope (Olympus Co., Ltd., OLS5000), and the roughened surface of the roughened copper foil was measured in accordance with ISO25178. Specifically, the surface profile of the area of the roughened surface of the roughened copper foil with an area of 16384 μm ² was measured by the above-mentioned laser microscope with a 100x lens with a numerical aperture (NA) of 0.95. For the surface profile of the roughened surface obtained, noise removal and primary linear surface inclination correction are performed, and the surface properties are analyzed to implement the maximum height Sz, the spread area ratio of the interface Sdr, the aspect ratio Str of the surface properties, and the core part The measurement of the level difference Sk and the peak apex density Spd. At this time, Sz, Sdr, Str, and Sk are measured by setting the cut-off wavelength of the S filter to 0.55 μm and the cut-off wavelength of the L filter to 10 μm. On the other hand, Spd is measured by setting the cut-off wavelength of the S filter to 3 μm and the cut-off wavelength of the L filter to 10 μm. The results are shown in Table 1.

(8b) Plating circuit adhesion (shear strength) The obtained carrier-attached copper foil was used to produce a laminate for evaluation. That is, on the surface of the insulating resin substrate, a prepreg (manufactured by Mitsubishi Gas Chemical Co., Ltd., GHPL-830NSF, thickness 0.1mm) is laminated and a roughened copper foil with a carrier copper foil is laminated at a pressure of 4.0 MPa , Temperature 220 ℃, 90 minutes after thermocompression bonding, peel off the carrier, it can be used as the evaluation laminate copper clad laminate. Laminate the dry film on the evaluation laminate, and perform exposure and development. After the layered body covered by the developed dry film is pattern-plated to deposit a copper layer with a thickness of 14 μm, the dry film is peeled off. The copper portion exposed with the sulfuric acid-hydrogen peracid system etching solution was etched to prepare a circuit sample for measuring shear strength with a height of 15 μm, a width of 10 μm, and a length of 200 μm (a laminate 134 that forms the circuit 136 shown in FIG. 5). Using a bonding strength tester (manufactured by Nordson DAGE Corporation, 4000Plus Bondtester), the shear strength when biasing the circuit 136 from the side of the circuit sample for shear strength measurement was measured. That is, as shown in FIG. 5, the laminated body 134 forming the circuit 136 is placed on the movable platform 132, and each platform 132 moves in the direction of the arrow in the figure, and the detector 138 is fixed in advance and the circuit 136 is pressed. A lateral force is applied to the side of the circuit 136 to shift the circuit 136 in the lateral direction. The force (gf) at this time is measured by the detector 138 and used as the shear strength. At this time, the test type is a destruction test, and the measurement is performed under the conditions of a test height of 5μm, a descending speed of 0.050mm/s, a test speed of 200μm/s, a tool movement amount of 0.05mm, and a failure identification point of 10%. The obtained shear strength is evaluated as the following benchmark evaluation, when evaluating A or B, it is judged as qualified. The results are shown in Table 1. ＜Shear strength evaluation standard＞ ‐Evaluation A: The shear strength is above 12.50gf ‐Evaluation B: The shear strength is 11.50gf or more but less than 12.50gf ‐Evaluation C: The shear strength is less than 11.50gf

(8c) High frequency characteristics The obtained copper foil with a carrier was used to produce a copper-clad laminate. That is, a roughened copper foil with carrier copper foil is laminated on the surface of the substrate (dielectric positive connection Df=0.005 at 30 GHz), and after thermocompression bonding, the carrier is peeled off to form a copper-clad laminate. For this copper clad laminate, the same method as (8b) above (dry film lamination, exposure and development, pattern plating, and etching after dry film peeling) is used to form a microstrip line with a circuit length of 300mm, which becomes a transmission Substrate for characteristic measurement. Use a network analyzer (Keysight Corp., N5225B) to measure the transmission characteristics of the substrate for measuring transmission characteristics at a characteristic impedance of 50Ω±5Ω at a frequency from 10MHz to 50GHz to measure the transmission characteristics S21. Average the losses above 26GHz and below 30GHz, and evaluate them as the following benchmarks. Then, when the high-frequency characteristics are evaluated as A or B, it is judged as a pass. The results are shown in Table 1. ＜High-frequency characteristic evaluation standard＞ ‐Evaluation A: The loss is 0.320dB/cm or less ‐Evaluation B: The loss is more than 0.320dB/cm and less than 0.350dB/cm ‐Evaluation C: The loss is more than 0.350dB/cm

Examples 3 and 5 Except for the following a) to c), the production and evaluation of the carrier-attached copper foil were performed in the same manner as in Example 1. The results are shown in Table 1. a) Carry out the preparation of the carrier as shown in the manual sequence below. b) Instead of the electrode surface of the carrier, on the precipitation surface of the carrier, a peeling layer, a supplementary metal layer and an ultra-thin copper foil are formed in this order. c) At this time, change the CBTA concentration and current density of the sintered plating process and the current density of the covered plating process to the values shown in Table 1.

(Preparation of the carrier) As the copper electrolyte, use the sulfuric acid copper sulfate solution with the following composition, use the titanium electrode with surface roughness Ra of 0.20μm on the cathode, and use DSA (Dimensional Stability Anode) on the anode. solution temperature 45 ℃, a current density of 55A / dm ² electrolysis, electrolytic copper foil having a thickness of 12μm was obtained as a carrier. <The composition of sulfuric acid copper sulfate solution>-Copper concentration: 80g/L-Free sulfuric acid concentration: 140g/L-Bis(3-sulfonic acid propyl) diphenyl sulfide concentration: 30mg/L-Diallyl dimethyl Base ammonium chloride polymer concentration: 50mg/L-Chlorine concentration: 40mg/L

Example 6 (comparison) Instead of the sintered plating process and the coated plating process, the ultra-thin copper foil was roughened through the black plating process shown below, and the production and evaluation of the carrier-attached copper foil were performed in the same manner as in Example 3. The results are shown in Table 1.

(Black plating process) For the surface of very thin copper foil, use the black copper electrolytic solution for roughening with the composition shown below, electrolyze it under the conditions of solution temperature of 30℃, current density of 50A/dm ² and time of 4sec to perform black roughening change. <Composition of copper electrolytic solution for black roughening>-Copper concentration: 13g/L-Sulfuric acid concentration: 70g/L-Chlorine concentration: 35mg/L-Sodium polyacrylate concentration: 400ppm

10: Very thin copper foil 11: Insulating resin substrate 11a: base material 11b: Lower circuit 12: Prepreg 13: Coating layer 14: Through hole 15: Electroless copper plating 16: dry film 17: Electrical copper plating 17a: Wiring part 18: Wiring 132: movable platform 134: layered body 136: Circuit 138: Detector

[Figure 1] is a flow chart illustrating the project of the MSAP method, showing the first half of the project (project (a) ~ (d)). [Figure 2] is a flowchart illustrating the process of the MSAP method, showing the diagram of the second half of the process (project (e) ~ (g)). [Figure 3] The load curve determined according to ISO25178 and a diagram illustrating the load area ratio. [Figure 4] Separate the load area ratio Smr1 of the protrusion peak and the core part determined in accordance with ISO25178, the load area ratio Smr2 of the separated protrusion valley part and the core part, and a diagram illustrating the level difference Sk of the core part. [Figure 5] is a schematic diagram illustrating the method of measuring shear strength.

Claims (11)

A roughened copper foil, which is a roughened copper foil with a roughened surface on at least one side. The roughened surface is based on ISO25178 at the cut-off wavelength of 0.55μm for the S filter and the cutoff wavelength for the L filter. The spread area ratio Sdr of the interface measured under the condition of 10μm is 0.50% or more and 7.00% or less. According to ISO25178, the peak apex density Spd measured under the conditions of the cut-off wavelength of 3.0μm by the S filter and 10μm by the L filter It is 2.00×10 ⁴ mm ^-2 or more and 3.30×10 ⁴ mm ^-2 or less. The roughened copper foil described in claim 1, wherein the spread area ratio Sdr of the aforementioned interface is 0.50% or more and 4.00% or less. The roughened copper foil according to claim 1 or 2, wherein the ^{ratio of the peak apex density Spd (mm -2} ) to the spread area ratio Sdr (%) of the interface, that is, Spd/Sdr, is 7000 or more. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is the maximum height Sz measured under the conditions of the cut-off wavelength of 0.55μm by the S filter and 10μm by the L filter in accordance with ISO25178 (μm) and the apex density Spd (mm ^-2 ) of the aforementioned peak, that is, Sz×Spd is 20000 or more. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is one of the surface properties measured under the conditions of the cut-off wavelength of 0.55μm by the S filter and 10μm by the L filter in accordance with ISO25178 The aspect ratio Str is 0.90 or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is one of the core parts measured under the conditions of the cut-off wavelength of 0.55μm formed by the S filter and 10μm formed by the L filter according to ISO25178 The level difference Sk is 0.05 μm or more and 0.30 μm or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is the maximum height Sz measured under the conditions of the cut-off wavelength of 0.55μm by the S filter and 10μm by the L filter in accordance with ISO25178 It is 1.3 μm or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is further provided with an anti-rust treatment layer and/or a silane coupling agent layer. A copper foil with a carrier, which is provided with a carrier, a peeling layer provided on the carrier, and a roughening treatment as described in any one of claims 1 to 8 on the peeling layer so that the roughening treatment faces outward. Copper foil. A copper clad laminate, characterized by being provided with a roughened copper foil as described in any one of claims 1 to 8. A printed wiring board characterized by being provided with a roughened copper foil as described in any one of Claims 1 to 8.

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