TW202248462A - Roughened copper foil, copper-clad laminated board, and printed wiring board - Google Patents

Abstract

Provided is a roughened copper foil simultaneously achieving excellent transmission characteristics and high peel strength when used in a copper-clad laminated board or a printed wiring board. This roughened copper foil has a roughened surface on at least one side. The microparticle tip volume of the roughened surface is 1.300 [mu]m3/particle or less, as calculated by the formula (Vmp + Vmc)/Spd, where Vmp is the material volume of a protruding peak portion, Vmc is the material volume of a core portion, and Spd is the density of peaks, and the cut level difference Rdc is 0.95 [mu]m or greater. Vmp, Vmc and Spd are values measured in compliance with ISO 25178, and Rdc is a value obtained as the difference in the cut level c in the height direction at load length ratios of 20% and 80% in compliance with JIS B0601-2013.

Description

Coarse treatment of copper foil, copper foil laminates and printed wiring boards

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

In the manufacturing process of printed wiring boards, copper foil is widely used in the form of copper foil laminates bonded to insulating resin substrates. In this respect, in order to prevent the peeling of wiring from occurring at the time of manufacturing a printed wiring board, it is desirable that copper foil and an insulating resin base material have high adhesive force. Therefore, in the usual copper foil for printed wiring board manufacture, roughening treatment is performed on the bonded surface of the copper foil to form irregularities including fine copper particles, and the irregularities are immersed in the insulating resin base material by pressing. The interior thus exerts an anchoring effect, thereby improving adhesion.

As a copper foil subjected to such a roughening treatment, for example, a surface-treated copper foil is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2018-172785). The surface-treated copper foil has a copper foil and at least For the roughened layer on one surface, the arithmetic average roughness Ra of the roughened layer side surface is 0.08 μm to 0.20 μm, and the TD (width direction) glossiness of the roughened layer side surface is 70% or lower. According to such a surface-treated copper foil, the falling off of the roughening particles provided on the surface of the copper foil is suppressed favorably, and the occurrence of wrinkles and streaks during lamination to an insulating substrate is favorably suppressed.

However, in recent years, with the high-functioning of portable electronic devices, in order to perform high-speed processing of large-capacity data, both digital and analog signals are increasing in frequency, and printed wiring boards suitable for high-frequency applications are required. In such a high-frequency printed wiring board, it is desired to reduce transmission loss in order to transmit high-frequency signals without degrading them. A printed wiring board is provided with copper foil processed into a wiring pattern and an insulating base material, but as the main loss in the transmission loss, the conductor loss caused by the copper foil and the dielectric loss caused by the insulating base material can be exemplified.

In this regard, a roughened copper foil with reduced transmission loss has been proposed. For example, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2015-148011), it is disclosed that for the purpose of providing a surface-treated copper foil with a small signal transmission loss and a laminate using the same, Treatment to control the skewness Rsk of the copper foil surface based on JIS B0601-2001 within a specific range of -0.35 to 0.53. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2018-172785 [Patent Document 2] Japanese Patent Laid-Open No. 2015-148011

As described above, in recent years, it is required to improve the transmission characteristics (high frequency characteristics) of printed wiring boards. In order to cope with such a request, it has been attempted to apply finer roughening treatment to the joint surface of the copper foil and the insulating resin base material. That is, in order to reduce the unevenness of the copper foil surface which is the cause of increased transmission loss, it is conceivable to perform micro-roughening treatment on the copper foil surface with small fluctuations (such as the surface of double-sided smooth foil or the electrode surface of electrolytic copper foil) . However, when such roughened copper foil is used for the processing of copper foil laminates or the manufacture of printed wiring boards, generally speaking, the peel strength between the copper foil and the base material is low, and the adhesion reliability is poor. question.

The inventors of the present invention obtained the following insights: by roughening the surface of the copper foil, the small front particle volume calculated based on the protruding peak volume Vmp, the core volume Vmc, and the peak apex density Spd, and The cutting level (level) difference Rdc is controlled within a specific range, which can make the copper foil laminated board or printed wiring board manufactured by using it have both excellent transmission characteristics and high peel strength.

Therefore, an object of the present invention is to provide a roughened copper foil having both excellent transmission characteristics and high peel strength when used in a copper foil laminate or a printed wiring board.

According to the present invention, the following aspects are provided. [Aspect 1] A roughened copper foil having a roughened surface on at least one side, and with respect to the above-mentioned roughened surface, based on the volume Vmp of the protruding peak portion per unit area (μm ³ /μm ² ), the solid volume of the core part per unit area Vmc (μm ³ /μm ² ), and the peak apex density Spd per unit area (pieces/μm ² ), the volume of tiny front-end particles calculated by the formula (Vmp+Vmc)/Spd 1.300 μm ³ / piece or less, and the cut-off degree difference Rdc is 0.95 μm or more. The above-mentioned Vmp, Vmc and Spd are based on ISO25178, at a magnification of 200 times, and the cut-off of the S-filter (S-filter, low-pass filter) The value measured under the condition that the wavelength is 0.3 μm and the cut-off wavelength of the L-filter (L-filter, high-pass filter) is 5 μm. In the roughness curve measured under the condition that the cut-off value of λs and the cut-off wavelength of cut-off value λc are 320 μm, it is the tangent in the height direction of the load length ratio (Rmr1) of 20% and the load length ratio (Rmr2) of 80% The value obtained from the difference of the degree of c (c(Rmr1)-c(Rmr2)). [Aspect 2] The roughened copper foil according to Aspect 1, wherein the degree of cutting difference Rdc of the roughened surface is 1.10 μm or more and 20.00 μm or less. [Aspect 3] The roughened copper foil according to Aspect 1 or 2, wherein the core portion solid volume Vmc per unit area of the roughened surface is 0.360 μm ³ /μm ² or less. [Aspect 4] The roughened copper foil according to any one of Aspects 1 to 3, wherein the sum of the volume Vmp of the protruding peak portion and the volume Vmc of the core portion of the roughened surface, that is, Vmp+Vmc, is: 0.380 μm ³ /μm ² or less. [Aspect 5] The roughened copper foil described in any one of Aspects 1 to 4, wherein the interface expansion area ratio Sdr of the roughened surface is 70% or less, and the above Sdr is based on ISO25178 at a magnification of 200 times, the value measured under the condition that the cut-off wavelength of the S-filter is 0.3 μm and the cut-off wavelength of the L-filter is 5 μm. [Aspect 6] The roughened copper foil described in any one of Aspects 1 to 5, wherein the difference Sk in the core portion of the roughened surface is 1.50 μm or more, and the above Sk is based on ISO25178 at a magnification of 20 times, the value measured under the condition that the cut-off wavelength of the S-filter is not performed and the cut-off wavelength of the L-filter is 320 μm. [Aspect 7] The roughened copper foil described in any one of Aspects 1 to 6, wherein the pole height Sxp of the roughened surface is 1.10 μm or more, and the above Sxp is based on ISO25178 at a magnification of 20 times, Values measured without S-filter cutoff and L-filter cutoff wavelength at 320 μm. [Aspect 8] The roughened copper foil according to any one of Aspects 1 to 7, wherein the peak apex density Spd per unit area of the roughened surface is 0.12 to 0.46/μm ² μm ² or less. [Aspect 9] The roughened copper foil according to any one of Aspects 1 to 8, further comprising an antirust treatment layer and/or a silane coupling agent treatment layer on the roughening treatment surface. [Aspect 10] The roughened copper foil according to any one of Aspects 1 to 9, wherein the roughened copper foil is an electrolytic copper foil, and the roughened surface exists on the side of the deposited surface of the electrolytic copper foil . [Aspect 11] A copper foil laminate including the roughened copper foil according to any one of Aspects 1 to 10. [Aspect 12] A printed wiring board including the roughened copper foil according to any one of Aspects 1 to 10.

Definitions Definitions of terms or parameters used to specify the present invention are as follows.

The so-called "load curve of the roughness curve" in this manual refers to the size of the solid part shown when the roughness curve is cut at the cutting degree c, as determined in accordance with JIS B0601-2013, as shown in Figure 1. The ratio is expressed as a function of c resulting from the curve. That is, the load curve of the roughness curve can also be called a curve showing the height at which the load length ratio Rmr(c) becomes 0% to 100%. The load length ratio Rmr(c), as shown in Fig. 2, is a parameter that indicates the ratio of the load length to the evaluation length of the roughness curve element at the degree of cutting c determined in accordance with JIS B0601-2013.

The so-called "cutting degree difference Rdc" or "Rdc" in this specification, as shown in Figure 3, refers to the two load length ratios Rmr1 and The parameter of the difference (c(Rmr1)-c(Rmr2)) of the cut-off degree c in the height direction of Rmr2 (wherein, Rmr1<Rmr2). In this specification, Rdc is calculated by designating Rmr1 as 20% and Rmr2 as 80%.

The so-called "surface load curve" in this specification refers to a curve indicating the height of the load area ratio from 0% to 100% determined based on ISO25178. The so-called load area ratio, as shown in Fig. 4, refers to a parameter indicating the area of a region above a certain height c. The load area ratio of height c corresponds to Smr(c) in Fig. 4 . As shown in Figure 5, starting from the load area ratio of 0%, take the point along the load curve where the difference of the load area ratio becomes 40%, and draw the secant line of the load curve so that the secant line of the load curve starts from the load area ratio of 0% Starting to move from the beginning, the position where the slope of the secant is the most gentle is called the central part of the load curve of the surface. With respect to the central portion, the straight line whose sum of squares of the deviation in the direction of the vertical axis becomes the smallest is called an equivalent straight line. The part included in the height range of 0% to 100% of the load area ratio of the equivalent straight line is called the core part. The part higher than the core is called the protruding peak, and the part lower than the core is called the protruding valley.

The so-called "load area ratio Smr1 separating the protruding peak part and the core part" in this manual refers to the load at the intersection point of the load curve indicating the height and surface of the upper part of the core part determined in accordance with ISO25178, as shown in Figure 5 Area ratio (i.e. the load area ratio to distinguish the core part from the protruding peak part) is a parameter. The so-called "load area ratio Smr2 separating the protruding valley part and the core part" in this manual refers to the load area ratio at the intersection point of the height of the lower part of the core part and the load curve determined according to ISO25178, as shown in Figure 5 (That is, the parameter that distinguishes the load area ratio of the core part and the protruding valley part).

The so-called "core difference Sk" or "Sk" in this manual refers to the value obtained by subtracting the minimum height from the maximum height of the core measured according to ISO25178, as shown in Figure 5, which refers to the load based on the equivalent straight line Parameters calculated from the height difference between 0% and 100% of the area ratio.

The so-called "protruding peak volume Vmp" or "Vmp" in this specification, as shown in FIG. 6, refers to a parameter indicating the volume of the protruding peak measured in accordance with ISO25178. In addition, the so-called "core solid volume Vmc" or "Vmc" in this specification refers to a parameter indicating the volume of the core measured in accordance with ISO25178, as shown in FIG. 6 . In this specification, Vmp and Vmc are calculated by designating the load area ratio Smr1 of the separated core portion and the protruding peak portion as 10%, and specifying the load area ratio Smr2 of the separated core portion and the protruding valley portion as 80%.

"Peak top density Spd" or "Spd" in this specification refers to a parameter indicating the number of peak tops per unit area measured in accordance with ISO25178. Spd can be calculated by dividing the number of peaks included in the contour surface by the projected area of the contour surface. In this specification, Spd is calculated by counting only peak tops larger than 5% of the maximum amplitude in the contour surface.

The so-called "micro front particle volume" in this specification refers to the solid volume of the protruding peak part per unit area Vmp (μm ³ /μm ² ), the solid volume of the core part per unit area Vmc (μm ³ /μm ² ), And the peak apex density Spd per unit area (number/μm ² ), a parameter calculated by the formula of (Vmp+Vmc)/Spd. Also, the so-called "Vmp+Vmc" in this specification refers to the sum of the protruding peak volume per unit area Vmp (μm ³ /μm ² ) and the core volume per unit area Vmc (μm ³ /μm ² ) The calculated parameters.

The so-called "pole height Sxp" or "Sxp" in this specification, as shown in Figure 7, refers to the parameter that represents the difference in height between the load area ratio p% and the load area ratio q% measured according to ISO25178. Sxp represents the difference between the average surface of the surface and the height of the surface after removal of particularly high peaks on the surface. In this specification, Sxp is calculated by designating the loaded area ratio p as 2.5%, and designating the loaded area ratio q as 50%.

The so-called "interface expansion area ratio Sdr" or "Sdr" in this specification refers to a parameter that indicates the extent to which the expansion area (surface area) of the defined area is larger than the area of the defined area measured in accordance with ISO25178. The smaller the value, the closer the surface shape is to flat, and the Sdr of a completely flat surface becomes 0%. On the other hand, the larger the value, the more unevenness of the surface shape.

Rdc can be calculated by measuring the surface distribution of a specific measurement length on the roughened surface using a commercially available laser microscope. Moreover, Vmp, Vmc, Spd, Sdr, Sk, and Sxp can be calculated by measuring the surface distribution of the specific measurement area in the roughening process surface, respectively, using a commercially available laser microscope. In this specification, Vmp, Vmc, Spd, and Sdr are measured under the conditions of a magnification of 200 times, an S-filter cutoff wavelength of 0.3 μm, and an L-filter cutoff wavelength of 5 μm. On the other hand, Rdc is set to be measured at a magnification of 20 times, the cutoff value λs is not cut off, and the cutoff wavelength of the cutoff value λc is 320 μm, and Sk and Sxp are set at a magnification of 20 times without S - The cutoff of the filter and the cutoff wavelength of the L-filter are measured under the condition of 320 μm. In addition, when both the objective lens and optical zoom are used in the measurement by a laser microscope, the said magnification corresponds to the value obtained by multiplying the magnification of an objective lens by the magnification of an optical zoom. For example, when the objective lens magnification is 100 times and the optical zoom magnification is 2 times, the magnification becomes 200 times (=100×2). In addition, preferable measurement conditions and analysis conditions for the surface distribution of the laser microscope are shown in the following examples.

In this specification, the "electrode surface" of the electrodeposited copper foil refers to the surface on the side that is in contact with the cathode when the electrodeposited copper foil is produced.

In this specification, the "precipitation surface" of the electrolytic copper foil refers to the surface on which the electrolytic copper is deposited when the electrolytic copper foil is produced, that is, the surface on the side not in contact with the cathode.

Roughening treatment copper foil The copper foil of this invention is a roughening treatment copper foil. The roughened copper foil has a roughened surface on at least one side. The roughened surface is based on the protruding peak volume per unit area Vmp (μm ³ /μm ² ), the core volume per unit area Vmc (μm ³ /μm ² ), and the peak apex density per unit area Spd (piece/μm ² ), the volume of tiny front-end particles calculated by the formula (Vmp+Vmc)/Spd is 1.300 μm ³ /piece or less. In addition, the degree of fracture Rdc of the roughened surface is 0.95 μm or more. By roughening the surface of the copper foil in this way, the volume of the small front particles and the degree of cutting Rdc are controlled within a specific range, and the copper foil laminate or printed wiring board manufactured using it can be excellent. Excellent transmission characteristics (high frequency characteristics) and high peel strength (such as normal peel strength and moisture resistance peel strength).

It is difficult to balance the excellent transmission characteristics and high peel strength. The reason is that in order to obtain excellent transmission characteristics, it is required to reduce the unevenness of the copper foil surface, and on the other hand, in order to obtain high peel strength, it is required to increase the unevenness of the copper foil surface, and the two are in a trade-off relationship. Here, as shown in FIG. 8 , the unevenness on the surface of the roughened copper foil includes a "roughened particle component" and a "fluctuation component" whose period is longer than that of the roughened particle component. Generally speaking, in order to obtain excellent transmission characteristics, it can be considered to perform micro-roughening treatment on the surface of copper foil with less fluctuation (such as the surface of double-sided smooth foil or the electrode surface of electrolytic copper foil) to form smaller roughened particles , but when such a roughened copper foil is used to manufacture a copper foil laminate or a printed wiring board, the peel strength between the copper foil and the base material generally becomes low.

In response to this problem, the inventors of the present invention have studied the influence of roughened particles and undulations on the surface of copper foil on transmission characteristics and peel strength. As a result, it was found that the fluctuation component of the copper foil is contrary to the expectation, and it is not easy to affect the transmission characteristics. The main reason is that the size of the coarsening particles will affect the transmission characteristics. Furthermore, the inventors of the present invention have found that by making the bumps (roughened particles) finer in order to improve the transmission characteristics, and making up for the lack of adhesion by using the undulations of the copper foil that have little influence on the transmission characteristics, It can have both excellent transmission characteristics and high adhesion reliability brought by high peel strength. Specifically, it has been found that excellent transport properties can be achieved by setting the volume of micro front particles relative to the volume of micro protrusions (roughened particles) that will affect transport properties to 1.300 μm ³ /piece or less. Furthermore, it has also been found that by setting the degree of cut Rdc under measurement conditions reflecting a wide range of heights of the roughened surface to be 0.95 μm or more, even small roughened surfaces where it is difficult to secure peel strength Particles can also use the undulations of the copper foil to achieve a higher peel strength between the copper foil and the substrate.

The mechanism by which the transport characteristics can be improved by controlling the volume of the tiny front particles is not necessarily clear, but it is considered to be as follows. Here, FIG. 9 shows a schematic cross-sectional view of protrusions (roughened particles) in which the boundary between the core portion and the protruding valley portion has been distinguished. As shown in FIG. 9 , the volume of the part where the core part of the protrusion coincides with the protrusion peak part per unit area (the part after removing the lower part of the protrusion corresponding to the protrusion valley part from the entire protrusion) is equal to Vmp+Vmc. Moreover, the peak apex density Spd represents the number of protrusions per unit area, so as shown in Figure 9, the result obtained by dividing Vmp+Vmc by Spd (=(Vmp+Vmc)/Spd) is equivalent to the number of tiny front particles per protrusion volume. Regarding this aspect, when it is assumed that Spd is the same (that is, the number of protrusions per unit area is the same) and Vmp+Vmc is different for two types of roughened surfaces, the size of the protrusions on the roughened surface with smaller Vmp+Vmc becomes smaller. Therefore, it is excellent in transmission characteristics. On the other hand, when it is assumed that Vmp+Vmc is the same (that is, the volume of the protrusion per unit area is the same) and that the Spd is different, the roughened surface with the larger Spd distributes the same volume to multiple The protrusions, that is, the size of each protrusion is reduced, so that the transmission characteristics are excellent. Therefore, by controlling the volume of the tiny front particles to a small value, the transmission characteristics can be improved.

For the roughened particle component and undulation component on the copper foil surface that will affect the transmission characteristics or peel strength, it can be determined by appropriately using the measurement magnification of the laser microscope, and the S-filter and L-filter or the cut-off value λs and λc to distinguish. Specifically, by measuring the roughened surface at a high magnification of 200 times, it is possible to accurately evaluate the fine unevenness of the roughened surface that affects transmission characteristics. Furthermore, by performing the measurement under the condition that the cutoff wavelength of the S-filter is 0.3 μm and the cutoff wavelength of the L-filter is 5 μm, the parameters of the roughened particle component in which the influence of the fluctuation component is eliminated can be obtained. Therefore, the small front particle volume, Vmp, Vmc, Vmp+Vmc, Spd and Sdr in the present invention can be said to be the parameters that truly reflect the roughened particles on the copper foil surface. By using these indicators, the transmission characteristics can be accurately evaluated. On the other hand, by measuring the roughened surface at a low magnification of 20 times, the height (waviness) of the entire roughened surface that affects adhesion reliability can be evaluated in a wide range. Furthermore, by measuring the roughened surface under the condition that the cut-off value λs or the cut-off value of the S-filter is not performed and the cut-off value λc or the cut-off wavelength of the L-filter is 320 μm, it is possible to obtain the roughened particle component and fluctuation The influence of both components is the parameter of the coarsening treatment surface as a whole. Therefore, Rdc, Sk, and Sxp in the present invention are parameters that not only reflect the roughened particle component of the copper foil surface, but also reflect the undulation component. By using these indicators, the peel strength can be accurately evaluated.

The Rdc of the roughened surface of the roughened copper foil is 0.95 μm or more, preferably 1.10 μm or more and 20.00 μm or less, more preferably 1.15 μm or more and 12.00 μm or less, and more preferably 1.20 μm or more and 6.00 μm or less At most, it is preferably not less than 1.25 μm and not more than 4.00 μm. If the Rdc is within the above range, excellent transmission characteristics can be ensured, and the anchoring effect can be effectively exerted to achieve high peel strength.

The volume of the tiny front-end particles on the roughened surface of the roughened copper foil is 1.300 μm ³ /unit or less, preferably 0.300 μm ³ /unit or more and 1.300 μm ³ /unit or less, more preferably 0.400 μm ³ /unit or more than 1.300 μm ³ /piece or less, more preferably 0.500 μm ³ /piece or more and 1.300 μm ³ /piece or less, particularly preferably 0.500 μm ³ /piece or more and 1.200 μm ³ /piece or less. If the volume of the front particle is small within the above range, the peel strength will be high and excellent transport characteristics will be realized.

The core portion solid volume Vmc per unit area of the roughened surface of the roughened copper foil is preferably 0.360 μm ³ /μm ² or less, more preferably 0.040 μm ³ /μm ² or more and 0.320 μm ³ /μm ² or less, and further Preferably at least 0.070 μm ³ /μm ² and at least 0.290 μm ³ /μm ² , especially preferably at least 0.100 μm ³ /μm ² and at least 0.260 μm ³ /μm ² , most preferably at least 0.130 μm ³ /μm ² and at least 0.230 μm ³ / μm ² or less. If the Vmc is within the above-mentioned range, it is easy to control the volume of the tiny front particles within the above-mentioned range, and the peeling strength is high, and more excellent transmission characteristics can be realized.

The sum of the protruding peak volume Vmp and the core volume Vmc of the roughened surface of the roughened copper foil, namely Vmp+Vmc, is preferably 0.380 μm ³ /μm ² or less, more preferably 0.050 μm ³ /μm ² or more than 0.340 μm ³ /μm ² or less, more preferably 0.090 μm ³ /μm ² or more, 0.310 μm ³ /μm ² or less, particularly preferably 0.130 μm ³ /μm ² or more and 0.280 μm ³ /μm ² or less, most preferably 0.140 μm ³ /μm 2 μm ² or more and 0.250 μm ³ /μm ² or less. If Vmp+Vmc is within the above range, it is easy to control the volume of the tiny front particles within the above range, the peel strength is high, and more excellent transmission characteristics can be realized.

^The peak apex density Spd per unit area of the roughened surface of the roughened copper foil is preferably 0.12 to 0.46/μm ² , more preferably 0.13 to ^0.44 /μm ² , more preferably 0.14 to 0.37/μm ² , more preferably 0.15 to ^{0.31/μm 2 ,} most preferably ^0.16 to ^{0.28/μm 2 .} If the Spd is within the above range, it is easy to control the volume of the tiny front particles within the above range, the peel strength is high, and more excellent transmission characteristics can be realized.

The interface development area ratio Sdr of the roughened surface of the roughened copper foil is preferably 70% or less, more preferably 5% or more and 65% or less, further preferably 10% or more and 60% or less, and most preferably 15% or more Less than 55%, preferably more than 20% and less than 50%. If it is Sdr in the said range, it will become a shape with many unevenness|corrugation conveniently for securing high peel strength and realizing more excellent transmission characteristic.

The core portion degree difference Sk of the roughened surface of the roughened copper foil is preferably 1.50 μm or more, more preferably 1.58 μm or more and 20.00 μm or less, further preferably 1.65 μm or more and 12.00 μm or less, and most preferably 1.70 μm or more 8.00 μm or less, preferably 2.00 μm or more and 6.00 μm or less. When Sk is within the above range, the transmission characteristics are excellent, and the anchoring effect can be effectively exhibited to realize high peel strength.

The pole height Sxp of the roughened surface of the roughened copper foil is preferably 1.10 μm or more, more preferably 1.20 μm or more and 20.00 μm or less, further preferably 1.30 μm or more and 12.00 μm or less, especially preferably 1.40 μm or more and 8.00 μm or less Below, preferably 1.70 μm or more and 6.00 μm or less. When the pole height Sxp is within the above range, the transmission characteristics are excellent, and the anchoring effect can be effectively exerted to realize high peel strength.

The thickness of the roughened copper foil is not particularly limited, but is preferably not less than 0.1 μm and not more than 210 μm, more preferably not less than 0.3 μm and not more than 105 μm. Furthermore, the roughened copper foil of the present invention is not limited to those obtained by roughening the surface of ordinary copper foils, and may also be roughened or micro-roughened on the surface of copper foils with carriers. earner.

An example of the roughened copper foil of the present invention is shown in FIG. 10 . As shown in Figure 10, the roughened copper foil of the present invention can be formed by roughening the surface of the copper foil with specific undulations (such as the deposition surface of the electrolytic copper foil) under desired low roughening conditions Fine roughened particles are better produced. Therefore, according to a preferred aspect of the present invention, the roughened copper foil is an electrolytic copper foil, and the roughened surface exists on the deposition surface side of the electrolytic copper foil. Furthermore, the roughened copper foil may have a roughened surface on both sides, or may have a roughened surface only on one side. Typically, the roughened surface has a plurality of roughened particles, and it is preferable that the plurality of roughened particles each contain copper particles. Copper particles may contain metallic copper or may contain a copper alloy.

The roughening treatment for forming the roughened surface can be preferably performed by forming roughening particles with copper or copper alloy on the copper foil. The copper foil before the roughening treatment may be unroughened copper foil, or pre-roughened. Regarding the surface of the copper foil to be roughened, the ten-point average roughness Rz measured in accordance with JIS B0601-1994 is preferably from 1.50 μm to 20.00 μm, more preferably from 2.00 μm to 10.00 μm. If it is in the said range, it will become easy to provide the surface distribution required for the roughening process copper foil of this invention to a roughening process surface.

Roughening treatment, for example, is preferably performed at a temperature of 20°C to 40°C in a copper sulfate solution with a copper concentration of 7 g/L to 17 g/L and a sulfuric acid concentration of 50 g/L to 200 g/L. Under this condition, the electrolytic precipitation is performed at 10 A/dm ² or more and 50 A/dm ² or less. The electrolysis is preferably performed in a range of 0.5 seconds to 30 seconds, more preferably in a range of 1 second to 30 seconds, and still more preferably in a range of 1 second to 3 seconds. However, the roughened copper foil of the present invention is not limited to the above method, and may be manufactured by any method.

When the above-mentioned electrolysis is separated out, it is preferred to make the following formula: R _L =L/D _C (wherein, R _L is the solution resistance index (mm L/mol), and L is the distance between the poles (anode-cathode) (mm), D _C is the charge carrier density (mol/L)) The solution resistance index R _L defined is 9.0 mm・L/mol or more, 20.0 mm・L/mol or less, more preferably 11.0 mm・L/mol or more Below 17.0 mm・L/mol. By increasing the solution resistance index _RL in this way, the voltage of the whole system becomes larger, and the voltage at the time of the bump formation reaction also becomes larger. This influences the shape of the protrusions, and as a result, protrusions of a shape suitable for imparting the surface distribution required for the roughened copper foil of the present invention can be preferably formed. Furthermore, the charge carrier density D _C can be calculated by summing up the product of each ion concentration and valence number for all ions present in the plating solution. For example, when copper sulfate solution is used as the plating solution, the charge carrier density D _C can be calculated according to the following formula: Dc=[H ⁺ ]×1+[Cu ²⁺ ]×2+[SO ₄ ^2- ]×2 (where [H ⁺ ] is the hydrogen ion concentration (mol/L) in the solution, [Cu ²⁺ ] is the copper ion concentration (mol/L) in the solution, [SO ₄ ^2- ] is the solution The sulfate ion concentration in (mol/L)).

The relationship between the solution resistance index R _L and the voltage is as explained below. First, the following formula is derived according to Ohm's law: V=ρ×L×I/S (where V is the voltage, ρ is the specific resistance, L is the distance between electrodes, I is the current, and S is the cross-sectional area between the electrodes) . That is, the voltage V is proportional to the specific resistance ρ, the inter-electrode distance L, and the current density (=I/S). Also, the specific resistance ρ is inversely proportional to the above-mentioned charge carrier density D _C . Therefore, when the current density is fixed, by increasing the solution resistance index (proportional to the inter-electrode distance L and inversely proportional to the charge carrier density D _C ), the voltage also increases. Therefore, the solution resistance index can be regarded as an index related to the resistance of the solution.

If necessary, the roughened copper foil may be provided with an antirust treatment to form an antirust treatment layer. The antirust treatment preferably includes plating treatment using zinc. The plating treatment using zinc may be any one of zinc plating treatment and zinc alloy plating treatment, and zinc alloy plating treatment is particularly preferably zinc-nickel alloy treatment. The zinc-nickel alloy treatment only needs to be a plating treatment including at least Ni and Zn, and may further include other elements such as Sn, Cr, Co, and Mo. For example, since the antirust treatment layer contains Mo in addition to Ni and Zn, the treated surface of the roughened copper foil has better adhesion to resin, chemical resistance, and heat resistance, and the etching residue is less likely to remain. The Ni/Zn adhesion ratio in the zinc-nickel alloy plating is preferably from 1.2 to 10 in mass ratio, more preferably from 2 to 7, and still more preferably from 2.7 to 4. Moreover, it is preferable that antirust treatment further includes chromate treatment, and this chromate treatment is more preferably performed on the surface of the plating containing zinc after the plating treatment using zinc. Thereby, rust resistance can be further improved. A preferred antirust treatment is a combination of zinc-nickel alloy plating followed by chromate treatment.

If necessary, the roughened copper foil may be treated with a silane coupling agent on the surface to form a layer treated with a silane coupling agent. Thereby, moisture resistance, chemical resistance, adhesiveness with an adhesive, etc. can be improved. The silane coupling agent-treated layer can be formed by appropriately diluting the silane coupling agent, applying it, and drying it. Examples of silane coupling agents include epoxy-functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane and 3-glycidyloxypropyltrimethoxysilane; Triethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy)propane Amino-functional silane coupling agents such as -3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane; mercapto-functional silanes such as 3-mercaptopropyltrimethoxysilane Silane coupling agent; olefin functional silane coupling agent such as vinyltrimethoxysilane and vinylphenyltrimethoxysilane; 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyl Acrylic functional silane coupling agents such as trimethoxysilane; imidazole functional silane coupling agents such as imidazole silane;

Based on the above reasons, the roughened copper foil is preferably provided with an antirust treatment layer and/or a silane coupling agent treatment layer on the roughened surface, more preferably with both the antirust treatment layer and the silane coupling agent treatment layer. The antirust treatment layer and the silane coupling agent treatment 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-clad laminated board It is preferable that the roughened copper foil of this invention is used for manufacturing the copper-clad laminated board for printed wiring boards. That is, according to a preferable aspect of this invention, the copper foil laminated board provided with the said roughening process copper foil is provided. By using the roughened copper foil of the present invention, the copper foil laminate can have both excellent transmission characteristics and high peel strength. This copper-clad laminate is comprised including the roughening process copper foil of this invention, and the resin layer provided in close contact with the roughening process surface of this roughening process copper foil. Roughened copper foil can be placed on one side of the resin layer or on both sides. The resin layer is composed of resin, preferably insulating resin. The resin layer is preferably a prepreg and/or a resin sheet. The so-called prepreg is a general term for composite materials obtained by impregnating base materials such as synthetic resin boards, glass boards, glass woven fabrics, glass non-woven fabrics, and paper with synthetic resins. Preferable examples of insulating resins include epoxy resins, cyanate resins, bismaleimide tristannium resins (BT resins), polyphenylene ether resins, and phenolic resins. Moreover, examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resins, polyimide resins, and polyester resins. In addition, from the viewpoint of improving insulation, etc., filler particles including various inorganic particles such as silicon oxide and aluminum oxide may be contained in the resin layer. The thickness of the resin layer is not particularly limited, but is preferably from 1 μm to 1000 μm, more preferably from 2 μm to 400 μm, and still more preferably from 3 μm to 200 μm. The resin layer may contain a plurality of layers. Resin layers such as prepregs and/or resin sheets can also be provided on the roughened copper foil via a primer resin layer coated on the surface of the copper foil in advance.

Printed Wiring Board The roughened copper foil of the present invention is preferably used in the manufacture of printed wiring boards. That is, according to a preferable aspect of this invention, the printed wiring board provided with the said roughening process copper foil is provided. By using the roughened copper foil of the present invention, the printed wiring board can have both excellent transmission characteristics and high peel strength. The printed wiring board of this aspect has a laminated layer structure including a resin layer and a copper layer. The copper layer is a layer derived from the roughened copper foil of the present invention. Also, the resin layer system is as described above for the copper foil laminate. In short, the printed wiring board can be constructed using known layers. As a specific example of a printed wiring board, one or both sides of a prepreg are bonded with the roughened copper foil of the present invention and hardened to form a laminate, and then a circuit is formed on one or both sides of the prepreg. Double-sided printed wiring boards; or multilayer printed wiring boards made by multilayering them. In addition, as other specific examples, flexible printed wiring boards, COF (Chip On Film, chip on film), TAB (Tape Automated Bonding, tape-and-reel automatic bonding) belt, etc. As another specific example, the above-mentioned resin layer is coated on the roughened copper foil of the present invention to form a resin-coated copper foil (RCC), and the resin layer is laminated on the above-mentioned printed circuit board as an insulating adhesive layer, Then use the roughened copper foil as all or part of the wiring layer, and use the modified semi-additive method (MSAP), subtractive method, etc. to form a circuit-based build-up wiring board; The build-up wiring board obtained by forming the circuit by the SAP method; and the direct buildup on wafer, which alternately repeats the lamination of the resin-attached copper foil and the circuit formation on the semiconductor integrated circuit. [Example]

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

Examples 1 to 15 produced the roughened copper foil of the present invention in the following manner.

(1) Manufacture of electrolytic copper foil Regarding Examples 1 to 9 and 11 to 15, a sulfuric acid copper sulfate solution having the composition shown below was used as the copper electrolyte, a titanium electrode was used for the cathode, and a DSA (dimensionally stable anode) was used for the anode. ), electrolysis was carried out at a solution temperature of 45°C and a current density of 55 A/dm ² to obtain electrolytic copper foil A with the thickness shown in Table 1. At this time, the electrode whose surface roughness was adjusted by polishing the surface with a #1000 buff was used as a cathode. <Composition of sulfuric acid copper sulfate solution> - Copper concentration: 80 g/L - Sulfuric acid concentration: 300 g/L - Glue concentration: 5 mg/L - Chlorine concentration: 30 mg/L

On the other hand, regarding Example 10, electrolytic copper foil B having the thickness shown in Table 1 was obtained using a sulfuric acid copper sulfate solution having the composition shown below as a copper electrolytic solution. At this time, the conditions were the same as those of the electrolytic copper foil A except for the composition of the sulfuric acid acidic copper sulfate solution. <Composition of sulfuric acid copper sulfate solution> - Copper concentration: 80 g/L - Sulfuric acid concentration: 260 g/L - Concentration of bis(3-sulfopropyl)disulfide: 30 mg/L - Diallyldimethylammonium chloride polymer concentration: 50 mg/L - Chlorine concentration: 40 mg/L

(2) Coarsening treatment Among the electrode surface and deposition surface of the above-mentioned electrolytic copper foil, for Examples 1 to 6, 10 and 12 to 15, the deposition surface side was roughened, and for Examples 7 to 9 and 11, the electrode surface side was roughened. treatment. Furthermore, the deposition surface of the electrodeposited copper foil used in Examples 1 to 6, 10 and 12 to 15, and the electrode surface of the electrodeposited copper foil used in Examples 7 to 9 and 11 were based on the use of a contact surface roughness meter Table 1 shows the ten-point average roughness Rz measured in JIS B0601-1994.

About Examples 1-8, the roughening process (1st roughening process) shown below was performed. The roughening treatment is carried out in the copper electrolytic solution for roughening treatment (copper concentration: 7 g/L to 17 g/L, sulfuric acid concentration: 50 g/L to 200 g/L, liquid temperature: 30°C) According to the conditions of solution resistance index, current density and time shown in Table 1 for each example, electrolysis and water washing are carried out.

About Examples 9-15, the 1st roughening process, the 2nd roughening process, and the 3rd roughening process shown below were performed sequentially. - The first roughening treatment is by copper electrolytic solution for roughening treatment (copper concentration: 7 g/L to 17 g/L, sulfuric acid concentration: 50 g/L to 200 g/L, liquid temperature: 30°C ), electrolysis and water washing were carried out according to the conditions of solution resistance index, current density and time shown in Table 1. - The second roughening treatment is carried out by performing electrolysis and water washing according to the conditions of solution resistance index, current density and time shown in Table 1 in the copper electrolytic solution for roughening treatment with the same composition as the first roughening treatment. - The third roughening treatment is to use copper electrolytic solution for roughening treatment (copper concentration: 65 g/L to 80 g/L, sulfuric acid concentration: 50 g/L to 200 g/L, liquid temperature: 45°C ), electrolysis and water washing were carried out according to the conditions of solution resistance index, current density and time shown in Table 1.

(3) Anti-rust treatment The anti-rust treatment shown in Table 1 was performed on the electrolytic copper foil after the roughening treatment. As this antirust treatment, regarding Examples 1 to 5, 7 and 8, the roughened surface of the electrolytic copper foil was treated with a pyrophosphoric acid bath at a concentration of potassium pyrophosphate of 100 g/L and a concentration of zinc of 1 g/L. , nickel concentration 2 g/L, molybdenum concentration 1 g/L, liquid temperature 40 ℃, current density 0.5 A/dm ² for zinc-nickel-molybdenum system antirust treatment. In addition, on the surface of the electrolytic copper foil that has not been roughened, use a pyrophosphoric acid bath with a potassium pyrophosphate concentration of 80 g/L, a zinc concentration of 0.2 g/L, a nickel concentration of 2 g/L, and a liquid temperature of 40°C. The current density is 0.5 A/dm ² and the zinc-nickel system antirust treatment is carried out. On the other hand, with regard to Examples 6 and 9 to 15, on both sides of the electrolytic copper foil, zinc-coating was carried out under the same conditions as the surface of the electrolytic copper foil in Examples 1 to 5, 7 and 8 which had not been roughened. Nickel-based anti-rust treatment.

(4) Chromate treatment Chromate treatment is performed on both sides of the electrolytic copper foil that has been subjected to the above-mentioned antirust treatment, and a chromate layer is formed on the antirust treatment layer. The chromate treatment was carried out under the conditions of chromic acid concentration 1 g/L, pH value 11, liquid temperature 25°C and current density 1 A/dm ² .

(5) Silane coupling agent treatment Wash the copper foil that has been subjected to the above chromate treatment, and then immediately perform silane coupling agent treatment, so that the chromate layer on the roughened surface is adsorbed on the silane coupling agent. The silane coupling agent treatment is carried out by blowing a solution of a silane coupling agent using pure water as a solvent to the roughened surface using a shower ring to perform adsorption treatment. As the silane coupling agent, 3-aminopropyltrimethoxysilane was used in Examples 1 and 3-8, and 3-glycidyloxypropyltrimethoxysilane was used in Examples 2 and 9-15. The concentration of the silane coupling agent was set at 3 g/L. After the silane coupling agent is adsorbed, the electric heater is finally used to evaporate the water to obtain a roughened copper foil with a specific thickness.

[Table 1] Table 1 Electrolytic copper foil Coarsening Anti-rust treatment Si treatment Processing surface first coarsening second coarsening third roughening type Thickness (μm) Rz (μm) Solution resistance index (mm L/mol) Current density (A/dm ² ) time(s) Solution resistance index (mm L/mol) Current density (A/dm ² ) time(s) Solution resistance index (mm L/mol) Current density (A/dm ² ) time(s) type type example 1 A 12 2.24 Precipitation surface 14.2 24.0 1.6 - - - - - - Zn-Ni-Mo Amino Example 2 A 12 2.24 Precipitation surface 14.2 24.0 1.6 - - - - - - Zn-Ni-Mo Epoxy Example 3 A 18 2.85 Precipitation surface 14.2 24.0 1.6 - - - - - - Zn-Ni-Mo Amino Example 4 A 35 4.92 Precipitation surface 14.2 24.0 1.6 - - - - - - Zn-Ni-Mo Amino Example 5 A 70 8.56 Precipitation surface 14.2 16.0 2.0 - - - - - - Zn-Ni-Mo Amino Example 6 A 70 8.56 Precipitation surface 14.2 16.0 2.0 - - - - - - Zn-Ni Amino Example 7* A 18 1.09 electrode surface 14.2 88.9 1.0 - - - - - - Zn-Ni-Mo Amino Example 8* A 18 1.24 electrode surface 14.2 32.0 1.9 - - - - - - Zn-Ni-Mo Amino Example 9* A 18 1.13 electrode surface 8.1 34.0 2.7 7.7 31.2 2.7 6.2 31.0 9.1 Zn-Ni Epoxy Example 10* B 18 0.56 Precipitation surface 7.6 23.0 6.2 7.7 14.2 6.2 6.7 8.6 25.0 Zn-Ni Epoxy Example 11* A 18 1.32 electrode surface 8.1 34.0 2.7 7.3 28.5 2.7 6.2 23.1 9.1 Zn-Ni Epoxy Example 12* A 12 2.14 Precipitation surface 7.6 31.8 2.3 7.3 30.1 2.3 6.7 26.7 9.3 Zn-Ni Epoxy Example 13* A 18 3.02 Precipitation surface 7.6 31.8 2.3 7.3 30.1 2.3 6.7 26.7 9.3 Zn-Ni Epoxy Example 14* A 35 4.53 Precipitation surface 7.6 31.8 2.3 7.3 30.1 2.3 6.7 26.7 9.3 Zn-Ni Epoxy Example 15* A 70 7.76 Precipitation surface 7.6 31.8 2.3 7.3 30.1 2.3 6.7 26.7 9.3 Zn-Ni Epoxy * indicates a comparative example.

Evaluation Various evaluations shown below were performed on the produced roughened copper foil.

(a) Surface texture parameters of the roughened surface Measurement of the roughened surface of the roughened copper foil was carried out in accordance with ISO25178 or JIS B0601-2013 by surface roughness analysis using a laser microscope (OLS-5000 manufactured by Olympus Co., Ltd.). At this time, Spd, Vmp, Vmc, and Sdr are as shown in Table 2, and the measurement magnification is set to 200 times (objective lens magnification 100 times × optical zoom 2 times) for measurement, and Rdc, Sk, and Sxp are as shown in Table 3. As shown, the measurement was performed with the measurement magnification set to 20 times (objective lens magnification 20 times). Other specific measurement conditions are shown in Tables 2 and 3. According to the conditions shown in Tables 2 and 3, the surface distribution of the obtained roughened surface was analyzed, and Spd, Vmp, Vmc, Sdr, Rdc, Sk, and Sxp were calculated. Also, based on the obtained values of Spd, Vmp, and Vmc, Vmp+Vmc and the micro front particle volume (=(Vmp+Vmc)/Spd) were calculated. The results are shown in Table 4.

[Table 2] Table 2 Measurement conditions Laser Microscope Model OLS-5000 manufactured by Olympus Co., Ltd. Objective lens magnification 100 times optical zoom 2 times viewing direction The direction of copper foil processing is perpendicular to the field of view test methods Specify the multiple area mode. In the grid registration mode, specify X=2, Y=2 for "column and row", specify X=64 μm, Y=64 μm for "pitch", and measure 2×2 adjacent areas ( 64 μm x 64 μm per place) Analytical conditions Object area When surface distribution is extracted 64.419 μm in length x 64.397 μm in width (1024×1024 pixels) When Spd is calculated In the above area when the surface distribution was captured, the area of 500 pixels × 500 pixels in the center When calculating Vmp, Vmc, and Sdr The entire area when the above surface distribution is captured (area of 1024 pixels × 1024 pixels) Specification ISO25178 face tilt correction Implemented by "automatically" F operation Set the Shape Removal Method to Multidimensional Surface and the Dimension to 1D. S-filter 0.3 μm L-filter 5 μm average method Average the measured values at 2×2 locations measured at the same time

[table 3] table 3 test methods Laser Microscope Model OLS-5000 manufactured by Olympus Co., Ltd. Objective lens magnification 20 times optical zoom none viewing direction The direction of copper foil processing is perpendicular to the field of view test methods Designate a separate area mode to measure 3 different parts Analysis method common conditions surface distribution extraction area 643.973 μm in length × 643.393 μm in width (designate an area of 1024 pixels × 1024 pixels on the area designation screen) face tilt correction Implemented by "automatically" Rdc target area Draw 3 lines with a length of 643.973 μm perpendicular to the treatment direction, draw 3 lines with a length of 643.393 μm parallel to the treatment direction, calculate the distribution on each line and average them Specification JIS B0601-2013 Cutoff value λs none Cutoff value λc 320 μm Sk Sxp target area The entire area specified when capturing the surface distribution (area of 1024 pixels × 1024 pixels) Specification ISO25178 F operation Set the Shape Removal Method to Multidimensional Surface and the Dimension to 1D. S-filter none L-filter 320 μm

(b) Peel strength between copper foil and substrate In order to evaluate the adhesion to the insulating base material of the roughened copper foil under normal temperature and high humidity environment, the normal-state peel strength and moisture-resistant peel strength were measured in the following manner.

(b-1) Normal peel strength As an insulating substrate, prepare 2 pieces of prepregs (thickness: 100 μm) mainly composed of polyphenylene ether, triallyl isocyanurate and bismaleimide resin, To pile up. The manufactured surface-treated copper foil was laminated on the stacked prepreg so that the roughened surface was in contact with the prepreg, and pressurized at 32 kgf/cm ² and 205°C for 120 minutes, and Copper-clad laminates are manufactured. Next, a circuit was formed on the copper foil laminate by an etching method, and a test substrate having a 3 mm-wide linear circuit was produced. Furthermore, regarding Examples 1, 2, and 12, before circuit formation, copper plating was performed on the copper foil side surface of the copper foil laminate until the thickness of the copper foil became 18 μm. Moreover, about Examples 4-6, 14, and 15, before circuit formation, the copper foil side surface of the copper foil laminated board was etched until the thickness of copper foil became 18 micrometers. The linear circuit obtained in this manner was peeled from the insulating substrate according to method A (90° peeling) of JIS C 5016-1994, and the normal peel strength (kgf/cm) was measured. Whether or not the obtained normal-state peel strength is good was evaluated according to the following criteria. The results are shown in Table 4. <Normal peel strength evaluation criteria> - Good: Normal peel strength is 0.40 kgf/cm or more - Bad: Normal peel strength is less than 0.40 kgf/cm

(b-2) Moisture Peel Strength The moisture-resistant peel strength (kgf/cm) was measured in the same procedure as the normal peel strength above, except that the test substrate with the linear circuit was immersed in boiling water for 2 hours before measuring the peel strength. Whether or not the obtained moisture-resistant peel strength is good was evaluated according to the following criteria. The results are shown in Table 4. <Evaluation Criteria for Moisture Peel Strength> - Good: Moisture peel strength of 0.40 kgf/cm or more - Poor: Moisture peel strength less than 0.40 kgf/cm

(c) Transfer characteristics A base material for high frequency (MEGTRON 6N manufactured by Panasonic) was prepared as an insulating resin base material. The roughened copper foil is laminated on both sides of the insulating resin substrate in such a way that the roughened surface is in contact with the insulating resin substrate. Using a vacuum press, the temperature is 190 ° C and the pressing time is 120 minutes. Laminate down to obtain a copper foil laminate with an insulation thickness of 136 μm. Thereafter, etching was performed on the copper-clad laminate to form a microstrip line so that the characteristic impedance became 50Ω, and a substrate for transmission loss measurement was obtained. The obtained substrate for measurement of transmission loss was measured for transmission loss (dB/cm) at 28 GHz using a network analyzer (N5225B manufactured by Keysight Technologies). Whether or not the obtained transmission loss is good was evaluated according to the following criteria. The results are shown in Table 4. <Evaluation criteria for transmission loss> - Good: The transmission loss is above -0.33 dB/cm - Poor: transmission loss does not reach -0.33 dB/cm

[Table 4] Table 4 Evaluation Surface texture parameters of roughened surface Copper foil-substrate peel strength transmission characteristics Small front particle volume (Vmp＋Vmc)/Spd (μm ³ /piece) Vmp (μm ³ /μm ² ) Vmc (μm ³ /μm ² ) Vmp＋Vmc (μm ³ /μm ² ) Spd (pcs/μm ² ) Sdr (%) Rdc (μm) Sk (μm) Sxp (μm) Normal Peel Strength (kgf/cm) Humid Peel Strength (kgf/cm) Transmission loss at 28 GHz (dB/cm) example 1 0.551 0.014 0.131 0.145 0.26 20 1.05 1.67 1.32 0.44 0.44 -0.30 Example 2 0.528 0.015 0.131 0.146 0.28 twenty one 0.96 1.67 1.32 0.45 0.44 -0.30 Example 3 0.869 0.018 0.148 0.165 0.19 twenty four 1.29 2.06 1.79 0.46 0.46 -0.31 Example 4 1.218 0.022 0.188 0.209 0.17 36 1.88 2.95 2.51 0.45 0.45 -0.31 Example 5 1.172 0.021 0.224 0.244 0.21 47 3.26 5.22 4.54 0.46 0.46 -0.32 Example 6 1.259 0.020 0.225 0.245 0.19 48 3.80 5.24 4.62 0.47 0.46 -0.32 Example 7* 0.982 0.017 0.226 0.242 0.25 40 0.90 1.42 1.01 0.37 0.37 -0.31 Example 8* 0.443 0.008 0.129 0.138 0.31 17 0.49 0.81 0.62 0.36 0.35 -0.30 Example 9* 5.131 0.063 0.553 0.616 0.21 111 1.23 2.03 2.06 0.56 0.56 -0.45 Example 10* 1.316 0.020 0.367 0.387 0.29 79 0.98 1.57 1.35 0.55 0.53 -0.40 Example 11* 1.733 0.025 0.372 0.397 0.23 77 1.23 1.91 1.68 0.56 0.56 -0.39 Example 12* 3.736 0.037 0.621 0.658 0.18 134 2.45 3.65 2.65 0.60 0.60 -0.45 Example 13* 5.999 0.039 0.583 0.622 0.10 118 2.43 3.42 2.88 0.62 0.61 -0.45 Example 14* 6.122 0.090 0.493 0.583 0.10 143 4.37 5.02 4.50 0.64 0.63 -0.44 Example 15* 2.525 0.031 0.510 0.541 0.21 109 5.82 7.53 7.39 0.67 0.65 -0.46 * indicates a comparative example.

Fig. 1 is a diagram for explaining the load curve of the roughness curve determined according to JIS B0601-2013. Fig. 2 is a diagram for explaining the load length ratio Rmr(c) determined in accordance with JIS B0601-2013. Fig. 3 is a diagram for explaining the cutting degree difference Rdc determined in accordance with JIS B0601-2013. Fig. 4 is a diagram for explaining the load curve and load area ratio Smr(c) of a surface determined in accordance with ISO25178. Fig. 5 is a graph for explaining the load area ratio Smr1 separating the protruding peak and the core, the load area ratio Smr2 separating the protruding valley and the core, and the core degree difference Sk determined according to ISO25178. FIG. 6 is a diagram for explaining the protruding peak portion solid volume Vmp and the core portion solid volume Vmc determined in accordance with ISO25178. FIG. 7 is a diagram illustrating the pole height Sxp determined in accordance with ISO25178. Fig. 8 is a diagram for explaining that the surface unevenness of roughened copper foil includes roughening particle components and undulation components. Fig. 9 is a schematic cross-sectional view of roughened particles, and is a diagram for explaining the volume of tiny front-end particles. Fig. 10 is a schematic view showing an example of the roughened copper foil of the present invention.

Claims (12)

A roughened copper foil having a roughened surface on at least one side, and with respect to the roughened surface, based on the volume Vmp of the protruding peaks per unit area (μm ³ /μm ² ), per unit area The solid volume of the core part Vmc (μm ³ /μm ² ), and the peak apex density per unit area Spd (pieces/μm ² ), the volume of the tiny front-end particles calculated by the formula (Vmp+Vmc)/Spd is 1.300 μm ³ / less than 1, and the cut-off degree difference Rdc is more than 0.95 μm, the above-mentioned Vmp, Vmc and Spd are based on ISO25178, at a magnification of 200 times, the cut-off wavelength of the S-filter is 0.3 μm and the cut-off wavelength of the L-filter is 5 μm The value measured under the above conditions, the above Rdc is based on JIS B0601-2013, the roughness curve measured under the conditions of 20 times the magnification, no cut-off value λs, and the cut-off wavelength of the cut-off value λc is 320 μm Among them, the value obtained as the difference (c(Rmr1)-c(Rmr2)) of the cutting degree c in the height direction between the load length ratio (Rmr1) of 20% and the load length ratio (Rmr2) of 80%. The roughened copper foil according to claim 1, wherein the cutoff degree difference Rdc of the roughened surface is not less than 1.10 μm and not more than 20.00 μm. The roughened copper foil according to claim 1 or 2, wherein the solid volume Vmc of the core portion per unit area of the roughened surface is 0.360 μm ³ /μm ² or less. The roughened copper foil according to claim 1 or 2, wherein the sum of the protruding peak volume Vmp and the core volume Vmc of the roughened surface, ie, Vmp+Vmc, is 0.380 μm ³ /μm ² or less. The roughened copper foil of claim 1 or 2, wherein the interface expansion area ratio Sdr of the roughened surface is 70% or less, and the above Sdr is based on ISO25178, with a magnification of 200 times and an S-filter cut-off wavelength of 0.3 μm and the cut-off wavelength of the L-filter is measured under the condition of 5 μm. As for the roughened copper foil of claim 1 or 2, wherein the difference Sk of the core portion of the roughened surface is 1.50 μm or more, the above Sk is based on ISO25178, at a magnification of 20 times, without the cut-off of the S-filter and The cut-off wavelength of the L-filter is the value measured under the condition of 320 μm. The roughened copper foil of claim 1 or 2, wherein the pole height Sxp of the above-mentioned roughened surface is 1.10 μm or more, and the above-mentioned Sxp is based on ISO25178, at a magnification of 20 times, without S-filter cut-off and L- The cutoff wavelength of the filter is the value measured under the condition of 320 μm. The roughened copper foil according to claim 1 or ^{2, wherein the peak apex density Spd per unit area of the roughened surface is 0.12 to 0.46/μm 2 .} The roughened copper foil according to Claim 1 or 2, wherein the above-mentioned roughened surface is further provided with an anti-rust treatment layer and/or a silane coupling agent treatment layer. The roughened copper foil according to claim 1 or 2, wherein the roughened copper foil is an electrolytic copper foil, and the roughened surface exists on the deposition surface side of the electrolytic copper foil. A copper foil laminate, which has the roughened copper foil according to claim 1 or 2. A printed wiring board comprising the roughened copper foil according to claim 1 or 2.

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