TW202146711A - Roughened copper foil, carrier-attached copper foil, copper clad laminate plate, and printed wiring board - Google Patents

Abstract

Provided is a roughened copper foil which can achieve both of excellent etching properties and high share strength in the processing of a copper clad laminate plate or the manufacture of a printed wiring board. The roughened copper foil has a roughened surface on at least one side thereof. In the roughened surface, the interface developed area ratio Sdr is 3.50% to 12.00% inclusive as measured in accordance with ISO25178 under the conditions including an S filter cut-off wavelength of 0.55 [mu]m and an L filter cut-off wavelength of 10 [mu]m. In the roughened copper foil, the core part level difference Sk is 0.15 [mu]m to 0.35 [mu]m inclusive as measured in accordance with ISO25178 under the conditions including an S filter cut-off wavelength of 0.55 [mu]m and an L filter cut-off 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 has been widely used as a manufacturing method of printed wiring boards suitable for miniaturization of circuits. The MSAP method is a method suitable for forming extremely fine circuits, and in order to activate this feature, it is performed using copper foil with a carrier. For example, as shown in FIGS. 1 and 2 , an ultra-thin copper foil 10 is press-adhered on a base substrate 11 a and an insulating resin substrate 11 having an underlying circuit 11 b using a prepreg 12 and a coating layer 13 . (Process (a)), after peeling off the carrier (not shown), through laser perforation as required, through holes 14 are formed (process (b)). Next, after applying electroless copper plating 15 (process (c)), through exposure and development using dry film 16 , masking with a specific pattern (process (d)), and applying electroless copper plating 17 (process (e) ). After removing the dry film 16 and forming the wiring portion 17a (process (f)), the unnecessary ultra-thin copper foil, etc., between the adjacent wiring portions 17a and 17a is removed by etching over the entire thickness of these (process (process (process)). g)), the wiring 18 can be 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.

As a copper foil subjected to such a roughening treatment, for example, in Patent Document 1 (Japanese Patent No. 6462961), it is disclosed on at least one side of the copper foil, and the roughening treatment layer, the antirust treatment layer and the silane coupling layer are based on this. Sequentially laminated surface-treated copper foil. In Patent Document 1, it is disclosed that the developed area ratio Sdr of the interface measured from the surface of the silane coupling layer of the relevant surface-treated copper foil is 8% or more for the purpose of producing a printed wiring board with excellent reflow heat resistance and less transmission loss. 140% or less, the quadratic mean 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.

In fact, several copper foils with a carrier that are excellent in fine circuit formability by the MSAP method or the like have been proposed. For example, in Patent Document 2 (International Publication No. 2016/117587), it is disclosed that the average distance between the surface peaks of the surface having the peeling layer side is 20 μm or less, and that the maximum height difference of the fluctuation between the peeling layer and the surface on the opposite side is 1.0 The copper foil with a carrier of the ultra-thin copper foil of μm or less can achieve both the fine circuit formability and the laser processability according to the relevant form. In addition, in Patent Document 3 (Japanese Patent Laid-Open No. 2018-26590), it is disclosed that the ratio Sp/ Copper foil with carrier with Spk of 3.271 or more and 10.739 or less. [Prior Art Literature] [Patent Literature]

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

In recent years, in order to form a finer circuit by the above-mentioned MSAP method, etc., in copper foil, it is calculated|required to make it smoother and the miniaturization of roughening particle|grains more. However, by smoothing the copper foil and miniaturizing the roughened particles, the etching properties of the copper foil regarding the miniaturization of the circuit can be improved, but the physical adhesion between the copper foil and the substrate resin and the like is lowered. In particular, with the thinning of the circuit, in the installation process of the printed wiring board, the circuit is easily peeled off by applying a physical stress (ie, shear stress) from the lateral direction to the circuit, and the problem of the decrease in productivity has become obvious. . At this point, one of the physical adhesion indexes between the circuit and the substrate is the shear strength (Share strength). In order to effectively avoid the peeling of the circuit, the shear strength needs to be kept above a certain level. However, in order to ensure the shear strength above a certain level, the roughening particles of the copper foil have to be increased, and there is a problem that it is difficult to achieve both the etching property.

The inventors of the present invention have found that, for the current roughened copper foil, by setting the developed area ratio of the interface defined in ISO25178 to the level difference Sk between Sdr and the core portion, a surface profile controlled within a specific range is given to the copper cladding. In the processing of laminates and even in the manufacture of printed wiring boards, both excellent etching properties and high shear strength can be achieved.

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

According to one aspect of the present invention, it is provided in the roughened copper foil having a roughened surface on at least one side, The above-mentioned roughened surface is based on ISO25178, and the developed area ratio Sdr of the interface measured under the conditions of the cutoff wavelength of S filter of 0.55μm and the cutoff wavelength of L filter of 10μm is 3.50% or more and 12.00% or less. According to ISO25178, A roughened copper foil having a core portion level difference Sk of 0.15 μm or more and 0.35 μm or less measured under the conditions of an S filter with a cutoff wavelength of 0.55 μm and an L filter with a cutoff wavelength of 10 μm.

According to another aspect of the present invention, there is provided a copper with a carrier including a carrier, a peeling layer provided on the carrier, and the roughened copper foil provided on the peeling layer with the roughened surface facing outward. foil.

According to another aspect of this invention, the copper clad laminate provided with the said roughening process copper foil is provided.

According to another aspect of this invention, the printed wiring board provided with the said roughening process copper foil is provided.

definition

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

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

In this specification, "surface load curve" (hereinafter, simply referred to as "load curve") refers to a curve with a load area ratio of 0% to 100% measured in accordance with ISO25178. The load area ratio is a parameter representing the area of the area above a certain height c, as shown in FIG. 3 . The load area ratio at the height c corresponds to Smr(c) in FIG. 3 . As shown in Fig. 4, the load area ratio is 0% along the load curve, and the difference between the load area ratios is 40%. The broken line of the load curve is drawn. Move from the load area ratio to 0%, and the inclination of the broken line is the most gentle. The position is called the central part of the load curve. For this central portion, a 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 included in the range of the height of the load area ratio of the equivalent straight line from 0% to 100% is called the core part. The part higher than the core part is called the protruding peak part, and the part lower than the core part is called the protruding valley part.

In this specification, the "level difference Sk of the core part" is the value obtained by subtracting the minimum height from the maximum height of the core part measured according to ISO25178. The parameter calculated from the height difference.

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

In the present specification, "aspect ratio Str of surface properties" means a parameter of isotropy or anisotropy of surface properties measured in accordance with ISO25178. Str is in the range of 0 to 1, usually Str>0.5 shows strong isotropy, on the contrary Str<0.3 shows strong anisotropy.

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

The developed area ratio Sdr of the interface, the level difference Sk of the core, the maximum height Sz, the aspect ratio Str of the surface features, and the peak vertex density Spd are the specific measurement areas of the surface that can be roughened (for example, 16384 μm ² The second dimension area) The surface profiles were measured by a commercially available laser microscope and calculated separately. In this specification, the values of the developed area ratio Sdr of the interface, the step difference Sk of the core, the maximum height Sz, and the aspect ratio Str of the surface features are set at the cutoff wavelength of 0.55 μm for the S filter and the cutoff wavelength for the L filter. The value measured under the condition of 10 μm. In addition, in this specification, the numerical value of the peak vertex density Spd is a value measured under the conditions of a cutoff wavelength of 3 μm formed by an S filter and a cutoff wavelength of 10 μm formed by an L filter.

In this specification, the "electrode surface" of the carrier refers to the surface that is in contact with the cathode when the carrier is fabricated.

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

Roughened copper foil The copper foil obtained by the present invention is a roughened copper foil. This roughened copper foil has a roughened surface on at least one side. The surface area ratio Sdr of the roughened surface is 3.50% or more and 12.00% or less, and the level difference Sk of the core part is 0.15 μm or more and 0.35 μm or less. In this way, in the roughened copper foil, the developed area of the interface is compared with the level difference Sk of Sdr and the core part, and the surface contour is controlled in each specific range by giving the surface profile in the processing of the copper clad laminate and the printed wiring board. In the manufacture, both excellent etching properties and high shear strength can be achieved.

Excellent etchability and high shear strength were originally difficult to balance. As mentioned above, in order to improve the etching properties of the copper foil, generally, it is required to make the roughened particles smaller. On the other hand, in order to improve the shear strength of the circuit, generally, it is required to make the roughened particles larger. . Therefore, the shear strength is not simply proportional to the specific surface area and roughening height, etc., which have been conventionally used for evaluation, and it is difficult to control the shear strength. In this regard, the present inventors found that in order to obtain the correlation of physical properties such as etching property and shear strength, it is effective to evaluate the developed area ratio Sdr of the combined interface and the level difference Sk of the core portion. Then, by controlling these surface parameters within the above-mentioned specific ranges, it was found that even with a fine surface excellent in etching property, a roughened copper foil having an appropriate protrusion height and specific surface area that can ensure high shear strength can be obtained. . In this way, when the copper foil is roughened according to the present invention, excellent etching properties and high shear strength can be achieved, and therefore, high circuit adhesion from the viewpoints of excellent fine circuit formability and shear strength can be achieved. Conventionally, however, a technique for individually controlling the developed area ratio Sdr, the quadratic mean square root surface slope Sdq, and the aspect ratio Str of the surface properties has been known for the surface of the surface-treated copper foil (refer to the above-mentioned Patent Document 1). However, these parameters are all parameters obtained by including the protruding peak, and when controlling the generation of the protruding peak, the value may become too small. In this regard, the inventors of the present invention have found that, for the roughened surface, the protruding peaks are controlled by separately controlling the level difference Sk of the core portion that does not include the parameter of the protruding peak portion, and the developed area ratio Sdr of the parameter including the protruding peak portion. In addition, the roughened particles constituting the roughened surface can be evenly immersed in the resin, so that even a fine surface with excellent etchability can obtain a suitable protrusion height and specific surface area to ensure high shear strength. Roughened copper foil.

From the viewpoint that excellent etching properties and high shear strength can be achieved in a good balance, the developed area ratio Sdr of the interface of the roughened surface of the roughened copper foil is 3.50% or more and 12.00% or less, preferably 4.50% or more and 8.50 % or less, more preferably 4.50% or more and 6.00% or less. Within this range, even if it is a fine surface (roughened height) with excellent etching properties, a sufficient adhesion area between the copper clad laminate and the laminated resin during the manufacture of printed wiring boards can be ensured, and the shear strength can be improved. Circuit tightness of view.

From the viewpoint that excellent etching properties and high shear strength can be achieved in a good balance, the level difference Sk of the core portion of the roughened surface of the roughened copper foil is 0.15 μm or more and 0.35 μm or less, preferably 0.23 μm or more and 0.35 μm or less, more preferably 0.25 μm or more and 0.35 μm or less. Within such a range, even if it is a fine surface (roughened height) excellent in etching property, each roughened particle constituting the roughened surface is evenly immersed in the resin, and the adhesiveness with the resin is 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 peak portion) is an improvement in circuit adhesion from the viewpoint of difficulty in imparting shear strength. In this section, parameters such as the maximum height Sz used in the previous evaluations include the prominent peaks. Therefore, according to such a parameter, when the improvement of the circuit adhesion is achieved, the roughening height tends to be increased, and as a result, the etching property tends to decrease. In contrast, the level difference Sk of the core portion is a parameter that does not include the protruding peak portion as described above. Therefore, when the level difference Sk of the core portion is used as an evaluation index, the surface shape which improves the adhesion with the resin optimally can be accurately obtained, and as a result, the increase in the roughening height can be suppressed.

The roughened copper foil is preferably 0.038 or more and 0.050 or less, preferably 0.045 or more and 0.050, and the ratio Sk/Sdr of the layer difference Sk (μm) of the developed area ratio Sdr (%) of the interface of the roughened surface to the surface of the roughened surface. the following. Within such a range, the unevenness of the height of the unevenness of the roughened surface will be further reduced, and the unevenness of the roughened surface will not be increased (that is, the surface area will be large), and the height of the core portion can be sufficient. make sure. That is, the level difference Sk of the core portion is a parameter obtained by excluding the protruding peak portion, while the developed area ratio Sdr is a parameter obtained by including the protruding peak portion. Therefore, when the number of protruding peaks is increased or decreased, the value of the level difference Sk of the core portion is constant, and the value of the developed area ratio Sdr is also changed. Therefore, by controlling the ratio of the level difference Sk of the core portion and the developed area ratio Sdr to the above-mentioned range, the generation of protruding peaks can be suppressed for the roughened surface, thereby constituting each roughening of the roughened surface. The particles tend to sink evenly into the resin. As a result, excellent etching properties and high shear strength can be achieved in a better balance.

The roughened copper foil is preferably the product Sz×Sk of the maximum height Sz (μm) of the roughened surface and the level difference Sk (μm) of the core part of 0.25 or more and 0.50 or less, more preferably 0.36 or more and 0.50 or less. Within such a range, the uneven shape of the roughened surface can further suppress the generation of protruding peaks, and can be more suitable for a high-quality balance to achieve excellent etching properties and high shear strength. In addition, from the viewpoint of realizing a fine surface with excellent etching properties, the maximum height Sz of the roughened surface of the roughened copper foil is preferably 1.6 μm or less, more preferably 1.0 μm or more and 1.4 μm or less, and even more 1.0 μm or more and 1.2 μm or less.

The peak density Spd of the roughened surface of the roughened copper foil is ^{preferably 2.00×10 4} mm ^-2 or more and 3.00×10 ⁴ mm ^-2 or less, preferably 2.20×10 ⁴ mm ^-2 or more and 3.00×10 ⁴ mm ^-2 or less, more preferably 2.75×10 ⁴ mm ^-2 or more and 2.85×10 ⁴ mm ^-2 or less. In this way, sufficient adhesion points between the copper clad laminate and the laminated resin can be ensured when manufacturing the printed wiring board, and the circuit adhesion in terms of shear strength can be improved more effectively.

The aspect ratio Str of the roughened surface of the roughened copper foil is preferably 0.2 or more and 0.5 or less, preferably 0.24 or more and 0.50 or less, more preferably 0.45 or more and 0.50 or less. Within such a range, the roughened surface will have fluctuations that are suitable for adhesion to the resin. As a result, even if it is a fine surface excellent in etching property, the circuit adhesiveness from a viewpoint of shear strength can be improved effectively.

The thickness of the roughened copper foil is not particularly limited, but 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 roughened copper foil is not limited to the surface of the usual copper foil, and the roughened copper foil may be roughened on the surface of the copper foil with the carrier copper foil. Here, the thickness of the roughened copper foil does not include 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 the thickness in the above range is called an ultra-thin copper foil.

The roughened copper foil has a roughened surface on at least one side. That is, the roughened copper foil may have a roughened surface on both sides, and may have a roughened surface only on one side. The roughened surface is typically provided with a plurality of roughened particles (protrusions), and each of these pluralities of roughened particles is preferably composed of copper particles. The copper particles may be made of metallic copper or may be made of a copper alloy.

The roughening treatment to form the roughened surface is preferably performed on the copper foil to form roughened particles with copper or a copper alloy. For example, it is carried out according to the plating method of at least two types of plating processes including a sintering plating process in which fine copper particles are deposited and adhered on the copper foil, and a coating plating process in order to prevent the peeling of the fine copper particles. Roughening treatment is better. At this time, in the sintering plating process, carboxybenzotriazole (CBTA) is added to a copper sulfate solution containing a copper concentration of 5 g/L or more and 20 g/L or less and a sulfuric acid concentration of 180 g/L or more and 240 g/L or less. Electrodeposition is preferably performed at a concentration of not less than 29 ppm and at a temperature of not less than 15° C. and not more than 35° C. and not less than 14 A/dm ^{2 and not} more than 24 A/dm ^{2 .} In addition, the coating plating process is carried out in a copper sulfate solution containing a copper concentration of 50 g/L or more and 100 g/L or less and a sulfuric acid concentration of 200 g/L or more and 250 g/L or less. dm ² or more and 4A/dm ² or less, preferably electrodeposition. In this regard, in the sintering plating process, the carboxybenzotriazole within the above concentration range is added to the plating solution to maintain the etchability close to pure copper. The roughened particles constituting the roughened surface are evenly immersed in the resin, so that it is easy to form on the surface with appropriate protrusions that satisfies the above-mentioned surface parameters. Furthermore, in the sinter plating process and the coating plating process, electrodeposition is performed at a lower current density than in the conventional method, and suitable protrusions satisfying the above-mentioned surface parameters can be easily formed on the treated surface.

As desired, the roughening-treated copper foil system can be rust-proof, and a rust-proof layer may be formed. The anti-rust treatment preferably includes a plating treatment using zinc. The plating treatment using zinc may be either a zinc plating treatment or a zinc alloy plating treatment, and 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 further 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, preferably 2 or more and 7 or less, more preferably 2.7 or more and 4 or less. In addition, the antirust treatment may further include a chromate treatment, and this chromate treatment is preferably performed on a surface plated with zinc after a zinc plating treatment is used. By doing so, the rust resistance can be further improved. A particularly preferred anti-rust treatment is a combination of zinc-nickel alloy plating treatment followed by chromate treatment.

As desired, the surface of the roughened copper foil may be treated with a silane coupling agent, and a silane coupling agent layer may be formed. Thereby, moisture resistance, chemical resistance, adhesiveness of adhesives, etc. can be improved. The silane coupling agent layer is applied by appropriately diluting the silane coupling agent, and is formed by drying. Examples of silane coupling agents include epoxy-functional silane coupling agents such as 4-epoxypropylbutyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, etc., or 3-amine. propyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy) Amino-functional silane coupling agents such as propyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, or 3-hydrothiopropyltrimethoxysilane Hydrogen thio-functional silane coupling agent such as silane or olefin-functional silane coupling agent such as vinyltrimethoxysilane, vinylphenyltrimethoxysilane, etc., or 3-methylpropionyloxypropyltrimethoxysilane Acrylic-functional silane coupling agent such as silane, 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 preferably further provided with an antirust treatment layer and/or a silane coupling agent layer on the roughened surface, preferably both of the antirust treatment layer and the silane coupling agent layer. The antirust treatment layer and the silane coupling agent layer may be formed not only on the roughened surface side of the roughened copper foil, but also on the side where the roughened surface is not formed.

With carrier copper foil As described above, the roughened copper foil of the present invention may be provided in a form with a carrier copper foil. That is, according to a preferred aspect of the present invention, there is provided a copper foil with a carrier including a carrier, a release layer provided on the carrier, and the above-mentioned roughened copper foil provided on the release layer with the roughened surface facing outward. Of course, the copper foil with a carrier can be constituted by a known layer in addition to the use of the roughened copper foil of the present invention.

The carrier system supports the roughened copper foil to improve the handleability. A typical carrier system includes a metal layer. Examples of such a carrier include aluminum foil, copper foil, stainless steel (SUS) foil, resin film or glass whose surface is coated with a metal such as copper, and copper foil is preferred. Although the copper foil may be either a rolled copper foil or an electrolytic copper foil, an 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.

Preferably, the surface of the carrier on the release layer side is smooth. That is, in the manufacturing process of the copper foil with a carrier, on the surface of the peeling layer side of a carrier, the ultra-thin copper foil (before roughening process is performed) is formed. When the roughened copper foil of the present invention is used in a form with a carrier copper foil, the roughened copper foil is obtained by subjecting such an ultra-thin copper foil to roughening. Therefore, by smoothing the surface of the release layer side of the carrier, the outer surface of the ultra-thin copper foil can also be smoothed, and the smooth surface of the ultra-thin copper foil is roughened, and it is easy to achieve the above-mentioned specific range. The developed area of the interface is worse than the level of Sdr and the core part by the roughened surface of Sk. In order to smooth the surface of the carrier on the side of the peeling layer, for example, the carrier is used on the cathode surface of the electrolytic foil, and it is ground with a specific type 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 through the peeling layer. On the outer side of the ultra-thin copper foil, it can be easily The smooth surface state of the above-mentioned roughened surface. The preferred type of grinding wheel is above #2000 and below #3000, more preferably above #2000 and below #2500.

The peeling layer weakens the peeling strength of the carrier, guarantees the stability of the strength, and has a functional layer that inhibits the mutual diffusion between the carrier and the copper foil during high-temperature compression molding. The release layer is generally formed on one side of the carrier, but may be formed on both sides. The peeling layer may be any of an organic peeling layer and an inorganic peeling layer. As an example of the organic component used for the organic peeling layer, a nitrogen-containing organic compound, a sulfur-containing organic compound, a carboxylic acid, etc. are mentioned. Examples of the nitrogen-containing organic compound include triazole compounds, imidazole compounds, and the like, and among them, the triazole compound is preferably a part that is easy to stabilize and 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 the sulfur-containing organic compound include thiothiobenzothiazole, thiocyanate, 2-benzimidazole thiol acid, and the like. As an example of a carboxylic acid, a monocarboxylic acid, a dicarboxylic acid, etc. are mentioned. On the other hand, as an example of the inorganic component used for the inorganic peeling layer, Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, a chromate treatment film, etc. are mentioned. However, the formation of the peeling layer may be performed on at least one surface of the carrier by contacting a solution containing the peeling layer component to fix the peeling layer component on the surface of the carrier. When the carrier is brought into contact with the release layer component-containing solution, the contact may be performed by dipping the release layer component-containing solution, spraying the release layer component-containing solution, or flowing the release layer component-containing solution. Otherwise, a method of forming a film of the peeling layer component by vapor deposition, sputtering, or the like can be employed. In addition, fixation of the carrier surface of the peeling layer component may be performed by adsorption or drying of the solution containing the peeling layer component, electrodeposition of the peeling layer component in the solution containing the peeling layer component, or the like. The thickness of the peeling 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 release layer and the carrier and/or the roughened copper foil. Examples of such other functional layers include auxiliary metal layers. The auxiliary metal layer is preferably made of nickel and/or cobalt. By forming such an auxiliary metal layer on the surface side of the carrier and/or the surface side of the roughened copper foil, the mutual diffusion between the carrier and the roughened copper foil can be suppressed during hot pressing at high temperature or for a long time. Guarantee the stability of the peel strength of the carrier. The thickness of the auxiliary metal layer is preferably 0.001 μm or more and 3 μm or less.

CCL 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 the preferable aspect of this invention, the copper clad laminate provided with the said roughening process copper foil is provided. By using the roughened copper foil of the present invention, in the processing of the copper clad laminate, both excellent etching properties and high shear strength can be achieved. This copper-clad laminate includes 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 may be provided on one side of the resin layer, or may be provided on both sides. The resin layer contains a resin, preferably an insulating resin. The resin layer is preferably a prepreg and/or a resin sheet. The prepreg system is a general term for composite materials impregnated with synthetic resins on substrates such as synthetic resin sheets, glass sheets, glass woven fabrics, glass non-woven fabrics, and paper. As a preferable example of an insulating resin, an epoxy resin, a cyanate resin, a bismaleic anhydride imide triazine resin (BT resin), a polyphenylene ether resin, a phenol resin, etc. are mentioned. Moreover, as an example of the insulating resin which comprises a resin sheet, insulating resin, such as an epoxy resin, a polyimide resin, a polyester resin, is mentioned. In addition, the resin layer may contain filler particles and the like made of various inorganic particles such as silica and alumina from the viewpoint of improving insulating properties and the like. The thickness of the resin layer is not particularly limited, but 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 may be constituted by plural layers. The resin layer, such as a prepreg and/or a resin sheet, may be provided on the roughened copper foil by coating the resin layer on the surface of the copper foil through preliminarily coating.

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 the preferable aspect of this invention, the printed wiring board provided with the said roughening process copper foil is provided. By using the roughened copper foil of the present invention, both excellent etching properties and high shear strength can be achieved in the manufacture of printed wiring boards. The printed wiring board obtained in this embodiment is composed of layers including a laminated resin layer and a copper layer. The copper layer is a layer derived from the roughened copper foil of the present invention. In addition, as for the resin layer, the part related to the copper clad laminate is as described above. In any case, the printed wiring board can be constituted by a known layer in addition to the use of the roughened copper foil of the present invention. As a specific example of the printed wiring board, one or both sides of the prepreg can be printed on one side or both sides of the prepreg to form the circuit on one side or both sides of the laminate to which the roughened copper foil of the present invention is adhered and cured. Wiring boards, or multilayer printed wiring boards, etc. Moreover, as another specific example, the roughened copper foil of this invention is formed on a resin film, and the flexible printed wiring board, COF, TAB tape etc. which form a circuit are formed. As a more specific example, the roughened copper foil of the present invention can be listed, forming a resin-coated copper foil (RCC) coated with the above-mentioned resin layer, using the resin layer as an insulating adhesive layer, and laminating it on the resin layer. After the above-mentioned printed circuit board, the roughened copper foil is used as all or a part of the wiring layer, and the multi-layer wiring board of the circuit is formed by methods such as the modified semi-additive (MSAP) method, the erasing treatment method, etc., or the roughening treatment is removed. Copper foil, multilayer wiring board for circuit formation by partial additive method, laminated copper foil with resin on semiconductor integrated circuit and direct lamination wafer for circuit formation are alternately repeated. As a specific example of further development, there are antenna elements formed by laminating the above-mentioned resin-coated copper foil on a substrate circuit, laminated on glass or resin film through an adhesive layer, and patterned for panels and displays. Electronic materials or electronic materials for window glass, electromagnetic wave shielding films, etc., which are coated with a conductive adhesive on the roughened copper foil of the present invention. 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 FIG. 1 and FIG. 2 can be adopted. [Example]

The present invention will be described more specifically through the following examples.

Examples 1~7, 9 and 10 The copper foil with the carrier with the roughened copper foil was produced and evaluated as follows.

(1) Preparation of the carrier Using the copper electrolyte with the composition shown below, the cathode, and the DSA (dimensionally stable anode) as the anode, electrolysis was carried out at a solution temperature of 50°C and a current density of 70A/dm ² , and the thickness of 18 μm was electrolyzed. Electrolytic copper foil is produced as a carrier. At this time, as a cathode, an electrode whose surface was ground with a #2000 grinding wheel to adjust the surface roughness was used. <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 Immerse the electrode surface of the pickled carrier 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, on the electrode surface of the carrier, the CBTA layer is formed as an organic peeling layer.

(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 0.001 μm adhered to the organic peeling layer. Thus, on the organic peeling layer, the nickel layer was formed as an auxiliary metal layer.

(4) forming the ultra-thin copper foil forming the metal layer support grant, the composition was immersed in a copper solution shown below, a solution temperature of 50 ℃, a current density of 5A / dm ² or more 30A / dm ² or less electrolysis, thickness 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 thus formed is roughened to form a roughened copper foil, thereby obtaining a carrier-attached copper foil. This roughening treatment consists of a sintering plating process for depositing and adhering fine copper particles on the ultra-thin copper foil, and a coating plating process for preventing the falling off of the fine copper particles. In the sintering and plating process, the carboxybenzotriazole (CBTA) of the concentration shown in Table 1 was added to an acidic copper sulfate solution containing a copper concentration of 10 g/L and a sulfuric acid concentration of 200 g/L at a liquid temperature of 25 °C. The current density is shown, and roughening treatment is carried out. In the subsequent coating plating process, electrodeposition was performed using an acidic copper sulfate solution containing a copper concentration of 70 g/L and a sulfuric acid concentration of 240 g/L under the smooth plating conditions of the solution temperature of 52° C. and the current density shown in Table 1. At this time, the CBTA concentration and current density of the sintering plating process and the current density of the coating plating process were appropriately changed from those shown in Table 1, and various samples with different characteristics of the roughened surface were cut.

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

(7) Silane coupling agent treatment An aqueous solution containing a commercially available silane coupling agent was adsorbed on the surface of the roughened copper foil side with the carrier copper foil, and the water was 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 About the copper foil with a carrier obtained in this way, the evaluation of various characteristics was performed as follows.

(8a) Surface property parameters of the roughened surface The roughened surface of the roughened copper foil was measured in accordance with ISO25178 through surface roughness analysis using a laser microscope (manufactured by Olympus Co., Ltd., OLS5000). 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 with a 100-fold lens with a numerical aperture (NA) of 0.95 in the above-mentioned laser microscope. The surface profile of the roughened surface obtained was subjected to noise removal and primary linear surface inclination correction, and then, through the analysis of the surface properties, the maximum height Sz, the developed area ratio Sdr of the interface, the aspect ratio Str of the surface properties, and the ratio of the core portion were performed. Determination of gradation difference Sk and peak vertex density Spd. At this time, the measurement of Sz, Sdr, Str, and Sk was performed with the cutoff wavelength of the S filter set to 0.55 μm and the cutoff wavelength of the L filter to be 10 μm. On the other hand, for the measurement of Spd, the cutoff wavelength of the S filter was 3 μm, and the cutoff wavelength of the L filter was 10 μm. The results are shown in Table 1.

(8b) Circuit Formability (Etchability Evaluation) Using the obtained copper foil with a carrier, a laminate for evaluation was produced. That is, as shown in FIG. 5 , on the surface of the insulating resin substrate 111, a roughening copper foil with a carrier is laminated via a prepreg 112 (manufactured by Mitsubishi Gas Chemical Co., Ltd., GHPL-830NSF, thickness 0.1 mm). The copper foil 110 was processed, and after thermocompression bonding at a pressure of 4.0 MPa and a temperature of 220° C. for 90 minutes, the carrier (not shown) was peeled off to obtain a copper-clad laminate for the evaluation laminate 114 . As shown in FIG. 5 , the roughened copper foil 110 includes roughened particles 110a on the surface. However, the etching property is evaluated by changing the required etching amount through the thickness of the ultra-thin copper foil. Therefore, as shown in FIG. 5 , the thickness of the roughened copper foil 110 of the laminated body 114 for evaluation is set to be equivalent to 1.5 μm (the thickness of the roughened particles 110 a is not included). It is necessary to perform a reduction in thickness by half etching and an increase in thickness by copper sulfate plating. The thickness of the roughened copper foil 110 was adjusted to 1.5 μm for the evaluation layer 114, and the etching solution was performed with sulfuric acid-hydrogen peroxide-based etching solution for every 0.1 μm, and the copper (including roughened particles) on the surface was measured. 110a) The amount (depth) of complete disappearance. The measurement was carried out for confirmation with an optical microscope (500 times). More specifically, the operation of confirming the presence or absence of copper with an optical microscope was repeated every time 0.1 μm was etched, and the value (μm) obtained by (number of etchings)×0.1 μm was used as an index of etchability. For example, an etching property of 2.5 μm means that 25 times of etching of 0.1 μm is performed, and the remaining copper is not detected by an optical microscope (ie, 0.1 μm×25 times=2.5 μm). That is, the smaller this value is, the less number of times the etching can be performed, the copper on the surface can be removed. That is, the smaller the value, the better the etching properties. The measured etching amount was evaluated as the following standard evaluation, and it was judged as acceptable when any of A to C was evaluated. The results are shown in Table 1. <Etchability Evaluation Criteria> - Evaluation A: The necessary etching amount is 2.3 μm or less ‐ Evaluation B: The necessary etching amount is more than 2.3μm and less than 2.5μm ‐ Evaluation C: The necessary etching amount is more than 2.5μm and less than 2.7μm - Evaluation D: The necessary etching amount is more than 2.7μm

(8c) Plated circuit adhesion (shear strength) A dry film was bonded to the above-mentioned laminate for evaluation, and exposure and development were performed. After the layered body masked with the developed dry film was plated with a pattern to deposit a copper layer with a thickness of 14 μm, the dry film was peeled off. The copper portion exposed by the sulfuric acid-hydrogen peroxide etchant was etched to prepare a circuit sample for shear strength measurement with a height of 15 μm, a width of 10 μm and a length of 200 μm (a laminate 134 of the circuit 136 shown in FIG. 6 was formed). The shear strength when the circuit 136 was biased from the side of the circuit sample for shear strength measurement was measured using a bond strength tester (Nordson DAGE, 4000Plus Bondtester). That is, as shown in FIG. 6, the laminated body 134 forming the circuit 136 is placed on the movable platform 132, each platform 132 moves in the direction of the arrow in the figure, and the pre-fixed detector 138 is pressed against the circuit 136. A lateral force is applied to the side surface of the circuit 136 to deflect the circuit 136 in the lateral direction, and the force (gf) at this time is measured by the detector 138 and used as the shear strength. At this time, the test type was a failure test, and the measurement was carried out under the conditions of a test height of 5 μm, a descending speed of 0.050 mm/s, a test speed of 200 μm/s, a tool movement amount of 0.05 mm, and a failure identification point of 10%. The obtained shear strength was evaluated as the following standard evaluation, and it was judged as pass when any one of A to C was evaluated. The results are shown in Table 1. <Shear Strength Evaluation Criteria> ‐ Evaluation A: Shear strength is 13.50gf or more ‐ Evaluation B: Shear strength is 12.50gf or more and less than 13.50gf ‐ Evaluation C: Shear strength is 12.00gf or more and less than 12.50gf ‐ Evaluation D: Shear strength is less than 12.00gf

Example 8 (comparison) The production and evaluation of the copper foil with a carrier were carried out in the same manner as in Example 1 except for the following a) to c). The results are shown in Table 1. a) Prepare the carrier as shown below. b) Instead of the electrode surface of the carrier, on the precipitation surface of the carrier, the peeling layer, the auxiliary metal layer and the ultra-thin copper foil are formed in this order. c) In place of the sintering plating process and the covering plating process, the ultra-thin copper foil is roughened through the black plating process shown below.

(Preparation of carrier) As the copper electrolyte, a sulfuric acid copper sulfate solution with the composition shown below was used, a titanium electrode with a surface roughness Ra of 0.20 μm was used for the cathode, and DSA (dimensionally stable anode) was used for the anode. The solution temperature was 45°C and the current density was 55A/dm ^{2 for} electrolysis, and an electrolytic copper foil with a thickness of 12 μm was obtained as a carrier. <The composition of sulfuric acid copper sulfate solution> - Copper concentration: 80g/L - Sulfuric acid concentration: 140g/L - Bis(3-sulfopropyl)diphenyl sulfide concentration: 30mg/L - Diallyldimethyl Ammonium Chloride Polymer Concentration: 50mg/L ‐ Chlorine Concentration: 40mg/L

(Black Plating Process) For the surface of the ultra-thin copper foil, use the copper electrolytic solution for black roughening with the composition shown below ^{, and conduct electrolysis under the conditions of solution temperature 30°C, current density 50A/dm 2} , and time 4sec to carry out 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 Substrate 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 110: Roughened copper foil 110a: Roughened particles 111: Insulating resin substrate 112: Prepreg 114: Laminates for Evaluation 132: Movable Platform 134: Laminate 136: Circuit 138: Detector

[Fig. 1] is a flow chart illustrating the process of the MSAP method, showing the first half of the process (process (a) to (d)). [Fig. 2] is a flow chart for explaining the process of the MSAP method, showing the process of the latter half (process (e) to (g)). [Fig. 3] A load curve determined in accordance with ISO25178 and a diagram illustrating the load area ratio. Fig. 4 is a diagram illustrating the load area ratio Smr1 of the protruding peak portion and the core portion determined in accordance with ISO25178, the load area ratio Smr2 of the separated protruding valley portion and the core portion, and the level difference Sk of the core portion. [ Fig. 5] Fig. 5 is a schematic cross-sectional view showing an example of a laminated body for evaluation before the circuit formability (etchability evaluation) is etched. [ Fig. 6] Fig. 6 is a schematic diagram illustrating a method of measuring shear strength.

Claims (11)

A roughened copper foil, which has a roughened surface on at least one side, The above-mentioned roughened surface is based on ISO25178, and the developed area ratio Sdr of the interface measured under the conditions of the cutoff wavelength of S filter of 0.55μm and the cutoff wavelength of L filter of 10μm is 3.50% or more and 12.00% or less. According to ISO25178, The level difference Sk of the core portion measured under the conditions of the cutoff wavelength of 0.55 μm formed by the S filter and the cutoff wavelength of 10 μm formed by the L filter was 0.15 μm or more and 0.35 μm or less. The roughened copper foil according to claim 1, wherein the ratio Sk/Sdr of the level difference Sk (μm) of the core portion to the developed area ratio Sdr (%) of the interface is 0.038 or more and 0.050 or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is based on ISO25178, and the maximum value measured under the conditions of a cutoff wavelength of 0.55 μm formed by an S filter and a cutoff wavelength of 10 μm formed by an L filter The Sz×Sk of the product of the height Sz (μm) and the step difference Sk (μm) of the core portion is 0.25 or more and 0.50 or less. The roughened copper foil according to claim 1 or 2, wherein the developed area ratio Sdr of the interface is 4.50% or more and 8.50% or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is based on ISO25178, and the peaks measured under the conditions of a cutoff wavelength of 3.0 μm formed by an S filter and a cutoff wavelength of 10 μm formed by an L filter The vertex density Spd is 2.00×10 ⁴ mm ^-2 or more and 3.00×10 ⁴ mm ^-2 or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is a surface measured under the conditions of a cutoff wavelength of 0.55 μm formed by an S filter and a cutoff wavelength of 10 μm formed by an L filter in accordance with ISO25178 The aspect ratio Str of the property is 0.2 or more and 0.5 or less. The roughened copper foil according to claim 1 or 2, wherein the roughened surface is based on ISO25178, and the maximum value measured under the conditions of a cutoff wavelength of 0.55 μm formed by an S filter and a cutoff wavelength of 10 μm formed by an L filter The height Sz is 1.6 μm or less. The roughened copper foil according to claim 1 or 2, further comprising a rust-preventive treatment layer and/or a silane coupling agent layer on the roughened surface. A copper foil with a carrier, which is characterized by having a carrier, a peeling layer provided on the carrier, and any one of claims 1 to 8 provided on the peeling layer with the aforementioned roughened surface as the outer side The roughened copper foil described. A copper-clad laminate characterized by having the roughened copper foil according to any one of claims 1 to 8. A printed wiring board comprising the roughened copper foil according to any one of Claims 1 to 8.

Images