TW202323594A - Roughened copper foil, copper-clad laminate, and method for manufacturing printed wiring board - Google Patents

Abstract

Provided is a roughened copper foil with which it is possible to obtain excellent transmission characteristics when used in a copper-clad laminate or a printed wiring board. This roughened copper foil has a roughened surface on at least one side thereof. The roughened surface has a developed interfacial area ratio Sdr, measured in accordance with ISO25178 and under 200x magnification, no S-filter, and a 5 [mu]m L-filter conditions, of 70.0% or below. In the surface on the opposite side from the roughened surface, the average value of L/S, this being the ratio of the grain boundary length L relative to the occupied area S calculated for each crystal grain in which the deviation angle from the (111) plane is 20 DEG or below in an observation field-of-view when analyzed by electron backscatter diffraction (EBSD) after being heated for one hour at 180 DEG C, is 13.0 [mu]m/[mu]m2 or below.

Description

Roughened copper foil, copper foil laminate, and manufacturing method of printed wiring board

The present invention relates to a method for roughening copper foil, copper foil laminate, and 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, copper foil and an insulating resin base material are desired to have high adhesive force in order to prevent wiring peeling at the time of printed wiring board manufacture. Therefore, with regard to the usual copper foil for printed wiring board manufacture, the bonding surface of the copper foil is roughened to form irregularities containing fine copper particles, and the irregularities are embedded into the interior of the insulating resin base material by press processing. Give play to the anchoring effect, thereby improving the adhesion.

As such a roughened copper foil, for example, a surface-treated copper foil is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2018-172785 ), which has a copper foil and a copper foil located on at least one surface of the copper foil. Roughened layer, and the arithmetic average roughness Ra of the side surface of the roughened layer is not less than 0.08 μm and not more than 0.20 μm, and the TD (width direction) glossiness of the surface of the roughened layer side is not more than 70%. According to such a surface-treated copper foil, the roughening particles provided on the surface of the copper foil are well suppressed from falling off, and the generation of wrinkles and streaks during lamination with an insulating substrate is well suppressed.

However, with the high-performance of portable electronic devices in recent years, both digital and analog signals have become high-frequency to process large-capacity data at high speed, so printed wiring boards suitable for high-frequency applications are required. Such a high-frequency printed wiring board is desired to reduce transmission loss so that high-frequency signals can be transmitted without degrading them. Printed wiring boards have copper foil and insulating base material processed into wiring patterns. As the main loss in transmission loss, examples include conductor loss caused by copper foil and dielectric loss caused by insulating base material.

In this respect, a roughened copper foil for reducing transmission loss is proposed. For example, in Patent Document 2 (Japanese Patent Laid-Open Publication No. 2015-148011), it is disclosed that surface-treated copper foil and a laminate using it are intended to provide a surface-treated copper foil with low signal transmission loss. The skewness Rsk of the copper foil surface based on JIS B0601-2001 is controlled within a specific range of -0.35 to 0.53, etc. [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, printed wiring boards have been required to further reduce transmission loss. However, there is a limit to satisfying such a request by improving only the roughened surface in copper foil as disclosed in Patent Documents 1 and 2.

The inventors of the present invention obtained the knowledge that, in the roughened copper foil, the developed area ratio Sdr of the interface on the roughened surface is controlled within a specific range, and the area ratio Sdr on the side opposite to the roughened surface is controlled. The grain boundary of crystal grains with a specific orientation in the plane can realize excellent transmission characteristics in the copper foil laminate or printed wiring board manufactured by using it.

Therefore, an object of the present invention is to provide a roughened copper foil that can realize excellent transmission characteristics 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, the above-mentioned roughened surface conforming to ISO25178, with a magnification of 200 times, without an S filter, and without an L filter of 5 μm The developed area ratio Sdr of the interface measured under the conditions is 70.0% or less, and the surface opposite to the above-mentioned roughened surface is measured by electron beam backscatter diffraction (EBSD) after heating at 180°C for 1 hour In the case of analysis, in the observation field, the average value of the ratio L/S of the grain boundary length L to the occupied area S calculated for each grain whose angle of deviation from the (111) plane is 20 degrees or less is 13.0 μm /μm ² or less. [Aspect 2] The roughened copper foil according to Aspect 1, wherein the angle of deviation from the (111) plane is 20 degrees or less on the surface opposite to the roughened surface in the observation field of view. The total occupied area A ₁ of the crystal grains is relative to the total occupied area A ₂ of the crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, and the grains whose angle of deviation from the (010) plane is 20 degrees or less Ratio _{A 1 /} ( _{A 2 + A 3} +A ₄ ) is not less than 0.10 and not more than 0.60. [Aspect 3] The roughened copper foil according to Aspect 1 or 2, wherein the average value of the L/S is 2.0 μm/μm ² or more and 11.0 μm/μm ² or less. [Aspect 4] The roughened copper foil described in any one of Aspects 1 to 3, wherein the above-mentioned roughened surface is based on ISO25178, under the conditions of 200 times the magnification, no S filter, and no L filter The level difference Sk of the core part measured below is 1.70 μm or less. [Aspect 5] The roughened copper foil according to any one of Aspects 1 to 4, wherein the roughened copper foil is an electrolytic copper foil, and the roughened surface exists on an electrode surface of the electrolytic copper foil side. [Aspect 6] The roughened copper foil according to any one of aspects 1 to 5, wherein the roughened surface has a plurality of roughened particles, and the roughened particles contain metal. [Aspect 7] A copper foil laminate comprising a resin layer and a roughened copper foil provided on at least one surface of the resin layer, wherein the roughened copper foil has a roughened surface on at least one side , the above-mentioned roughened surface is in contact with the above-mentioned resin layer, and the above-mentioned roughened surface is based on ISO25178, and the developed area ratio Sdr of the interface measured under the conditions of 200 times magnification, no S filter, and L filter 5 μm 70.0% or less, and when the surface of the above-mentioned roughened copper foil opposite to the above-mentioned roughened surface is analyzed by electron beam backscatter diffraction (EBSD), in the observation field of view, for The average value of the ratio L/S of the grain boundary length L to the occupied area S calculated for each crystal grain whose angle of deviation from the (111) plane is 20 degrees or less is 13.0 μm/μm ² or less. [Aspect 8] The copper foil laminate according to Aspect 7, wherein the surface of the roughened copper foil opposite to the roughened surface is offset from the (111) surface in the observation field of view The total occupied area A ₁ of crystal grains whose angle is less than 20 degrees is relative to the total occupied area A ₂ of crystal grains whose angle of deviation from (100) plane is less than 20 degrees, and the angle of deviation from (010) plane is Ratio A 1 of the sum of the total occupied area A _{3 of} crystal grains below 20 degrees and the total occupied area A ₄ of crystal grains whose angle of deviation from the (001) plane is below 20 degrees (A ₂ +A ₃ +A ₄ ) /(A ₂ +A ₃ +A ₄ ) is not less than 0.10 and not more than 0.60. [Aspect 9] A method of manufacturing a printed wiring board, comprising the steps of: preparing a roughened copper foil, wherein the roughened copper foil has a roughened surface on at least one side, and the roughened surface is in accordance with ISO25178 , under the conditions of 200 times magnification, no S filter, and L filter 5 μm, the developed area ratio Sdr of the interface measured is less than 70.0%; the above-mentioned roughened copper foil is applied to at least one surface of the resin layer Laminating the roughened surface in contact with the resin layer to produce a copper foil laminate; processing the roughened copper foil of the copper foil laminate to form a circuit; and roughening the circuit by etching processing; and when the surface of the above-mentioned circuit before the above-mentioned roughening treatment by etching is analyzed by the electron beam backscatter diffraction method (EBSD), in the observation field of view, for the deviation from the (111) plane The average value of the ratio L/S of the grain boundary length L to the occupied area S calculated for each crystal grain having an angle of 20 degrees or less is 13.0 μm/μm ² or less. [Aspect 10] The method of manufacturing a printed wiring board according to Aspect 9, wherein the surface of the circuit before the roughening treatment by etching is deviated from the (111) plane in the observation field of view It is the total occupied area A ₁ of crystal grains below 20 degrees relative to the total occupied area A ₂ of crystal grains whose angle of deviation from (100) plane is less than 20 degrees, and the angle of deviation from (010) plane is 20 degrees _{Ratio A 1 / ( _} A ₂ +A ₃ +A ₄ ) is not less than 0.10 and not more than 0.60.

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

In this specification, the "expanded area ratio Sdr of the interface" or "Sdr" is a parameter expressing the increase of the expanded area (surface area) of the defined area measured in accordance with ISO25178 relative to the area of the defined area in percentage. The smaller the value, the closer to a flat surface shape, and the Sdr of a completely flat surface is 0%. On the other hand, a larger value indicates a surface shape with more unevenness.

In this specification, the "surface load curve" refers to a curve showing the height of the load area ratio determined in accordance with ISO25178 from 0% to 100%. As shown in Fig. 1, the load area ratio is a parameter indicating the area of the area above a certain height c. The load area ratio at height c is equivalent to Smr(c) in Figure 1. As shown in Figure 2, the secant line of the load curve drawn from the load area ratio of 0% along the load curve so that the difference of the load area ratio is 40% moves from the load area ratio of 0%, and the slope of the secant line is the most gentle. The location is called the central portion of the load curve for the surface. The straight line that minimizes the sum of the squares of the deviations in the vertical axis direction in the central portion is called an equivalent straight line. The part included in the height range from 0% to 100% of the load area ratio of the equivalent straight line is called the core part. The part higher than the core part is called a protruding peak part, and the part lower than the core part is called a protruding valley part.

In this specification, "the step difference Sk of the core" or "Sk" is the value obtained by subtracting the minimum height from the maximum height of the core measured according to ISO25178, as shown in Figure 2, by means of an equivalent straight line The parameters calculated from the height difference between 0% and 100% of the load area ratio.

Sdr and Sk can be calculated by measuring the surface profile of a specific measurement area in the roughened surface with a commercially available laser microscope. In this specification, Sdr is measured under the conditions of 200 times magnification, no S filter, and 5 μm L filter. On the other hand, Sk was measured under the conditions of 200 times magnification, no S filter, and no L filter. In addition, when both the objective lens and optical zoom are used in the measurement with 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 is 200 times (=100×2). In addition, preferable measurement conditions and analysis conditions of the surface profile using a laser microscope were set as those 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 electrodeposited copper foil refers to the surface on which the electrodeposited copper is deposited during the manufacture of the electrodeposited copper foil, 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. This roughened copper foil has a roughened surface on at least one side. The developed area ratio Sdr of the interface of the roughened surface is 70.0% or less. In addition, when the surface of the roughened copper foil opposite to the roughened surface is analyzed by electron beam backscattering diffraction (EBSD) after heating at 180° C. for 1 hour, in the observation field, The average value of the ratio L/S of the grain boundary length L to the occupied area S calculated for each crystal grain whose angle of deviation from the (111) plane is 20 degrees or less is 13.0 μm/μm ² or less. In this way, in the roughened copper foil, the expansion area ratio Sdr of the interface on the roughened surface is controlled within a specific range, and the crystal grains of a specific orientation existing on the surface opposite to the roughened surface are controlled. Controlling the boundary, it is possible to achieve excellent transmission characteristics in copper foil laminates or printed wiring boards manufactured using it.

The mechanism by which excellent transmission characteristics can be realized by the configuration of the present invention is not necessarily clear, but it is considered as follows. First, if the developed area ratio Sdr of the interface in the roughened surface of the copper foil is 70.0% or less, the roughened surface will have a concavo-convex shape for realizing excellent transmission characteristics. Here, as shown in FIG. 3 , the unevenness of the roughened surface includes a "roughened particle component" and a "fluctuation component" with a longer period than the roughened particle component. The roughened particle component and the fluctuation component can be distinguished by using an S filter and an L filter of a laser microscope. Specifically, by measuring the roughened surface of the roughened copper foil under the condition of no S filter and L filter 5 μm, the parameter of the roughened particle component whose influence of the fluctuation component is removed can be obtained. In addition, 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 the transmission characteristics. Therefore, it can be said that the developed area of the interface in the present invention more accurately reflects the shape of the roughened particles on the roughened surface of the copper foil than Sdr.

On the other hand, as described above, the printed wiring board is required to further reduce the transmission loss, but there is a limit to satisfying this requirement only by improving the roughened surface in the copper foil. In this respect, in the roughened copper foil of the present invention, not only the roughened surface is controlled by the above-mentioned specific parameters, but also the surface on the opposite side to the roughened surface is also controlled by the above-mentioned specific parameters. The relationship between the surface of the roughened copper foil opposite to the roughened surface and the transmission characteristics can be described as follows. In one example of the manufacturing process of a printed wiring board, a copper foil laminate formed by bonding an insulating resin base material to the roughened surface of the roughened copper foil is formed by forming a photoresist layer or etching, etc., to form a circuit After that, resin is further laminated to cover the circuit. At this time, before laminating the resin, treatment for improving the reliability (adhesiveness, heat resistance, etc.) of the circuit and the surrounding resin is performed. As such a treatment for improving reliability, there is typically a treatment of partially dissolving (etching) the surface of the circuit to roughen it. In this way, since the roughening treatment by etching is performed after the circuit is formed, the affected part of the treatment is the surface of the circuit that is not in contact with the resin base material, that is, the surface of the roughened copper foil and the roughened surface. The face on the opposite side. In this respect, similarly to the roughened particles given at the time of copper foil production, the larger the roughening by the etching roughening process, the worse the transmission characteristics. Therefore, in order to achieve more excellent transmission characteristics, it is important not only to control the surface properties of the roughened surface (the side that is in close contact with the resin substrate) of the roughened copper foil, but also to control the surface on the opposite side. traits.

In general, dissolution of a metal structure including polycrystals proceeds along the portion (grain boundary) where crystal grains meet each other. Therefore, the fewer the grain boundaries of the crystal grains existing on the surface of the circuit, the fewer the parts that are strongly etched, and the transfer characteristics are relatively good compared with the case where there are more grain boundaries. Also, the number of atoms in contact with the etchant varies depending on the orientation of crystals present on the surface to be etched, and it is considered that the more atoms in contact with the etchant at the same time, the more efficient the dissolution. Therefore, it can be said that crystal grains having a smaller angle of deviation (tilt angle) from the (111) plane as a densely packed structure dissolve extremely quickly. In this way, the orientation and grain boundaries of crystal grains affect the progress of etching, and as a result, also affect the transmission characteristics.

In this regard, the roughened copper foil of the present invention focuses on crystals having an angle of deviation from the (111) plane of 20 degrees or less on the surface opposite to the roughened surface, which has a large influence on etching. grains, the average value of the ratio L/S of the grain boundary length L to the occupied area S in each grain is controlled below 13.0 μm/μm ² . That is, since the roughened copper foil satisfying the above-mentioned parameters dissolves extremely fast, there are fewer grain boundaries of particles with smaller angles of deviation from the (111) plane, so fewer parts are locally etched quickly. As a result, the surface shape of the circuit after the roughening treatment by etching becomes smooth, and the transmission characteristics can be improved.

The developed area ratio Sdr of the roughened surface of the roughened copper foil is not more than 70.0%, preferably not less than 5.0% and not more than 60.0%, more preferably not less than 10.0% and not more than 50.0%, further preferably not less than 20.0% and not more than 45.0% %the following. If the Sdr is within the above range, high adhesion to the resin base material will be ensured, and the roughened surface will have a shape rich in concavities and convexities for realizing excellent transmission characteristics.

The step difference Sk of the core portion of the roughened surface of the roughened copper foil is preferably 1.70 μm or less, more preferably 0.10 μm or more and 1.50 μm or less, further preferably 0.50 μm or more and 1.40 μm or less, especially preferably 0.90 μm Above 1.20 μm. As mentioned above, in the present invention, Sk (different from Sdr) is a parameter obtained by measuring the surface of the copper foil under the condition of no L filter, so as to more accurately reflect the overall surface shape of the copper foil. In this respect, if it is Sk within the above-mentioned range, the anchoring effect can be exhibited effectively, high adhesiveness with a resin base material can be ensured, and circuit formability can be improved.

The average value of L/S of the roughened copper foil on the side opposite to the roughened surface is 13.0 μm/μm ² or less, preferably 2.0 μm/μm ² or more and 11.0 μm/μm ² or less, more preferably 3.0 μm/μm ² to 10.0 μm/μm ² , more preferably 5.0 μm/μm ² to 9.0 μm/μm ² . If it is the average value of L/S within the above range, the roughening by etching can be made moderately, and the part that is locally rapidly etched can be suppressed. Therefore, when the roughening treatment by etching is performed after the circuit is formed, it can be achieved. The improvement of the reliability which is the original purpose, and the surface shape of the circuit becomes smooth, and the transmission loss is reduced.

The total number of crystal grains whose angle of deviation from the (111) plane is 20 degrees or less in the field of view when the surface of the roughened copper foil is analyzed by the above-mentioned EBSD Occupied area A ₁ is relative to the total occupied area A ₂ of crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, and the total occupied area A of crystal grains whose angle of deviation from the (010) plane is 20 degrees or less _3. The ratio A ₁ /(A ₂ +A ₃ +A ₄ ) of the sum (A ₂ +A ₃ +A ₄ ) of the total occupied area A ₄ of grains whose angle of deviation from the (001) plane is less than 20 degrees is better It is not less than 0.10 and not more than 0.60, more preferably not less than 0.15 and not more than 0.55, still more preferably not less than 0.20 and not more than 0.50. If A ₁ /(A ₂ +A ₃ +A ₄ ) is within the above range, there are fewer crystal grains with a smaller angle of deviation from the (111) plane that dissolve extremely rapidly during etching, but they exist moderately. As a result, when the roughening treatment by etching is performed after the circuit is formed, the intended reliability can be improved, the circuit surface shape can be smoothed, and the transmission loss can be further reduced.

The average value of L/S and A ₁ /(A ₂ +A ₃ +A ₄ ) of the roughened copper foil on the surface opposite to the roughened surface can be obtained by heating the roughened copper foil at 180°C One hour later, it was analyzed and identified by electron beam backscattering diffraction (EBSD). Analysis by electron beam backscatter diffraction (EBSD) can be performed well according to the procedure shown in the following examples. In addition, the reason for performing the analysis by EBSD after heating roughening process copper foil at 180 degreeC for 1 hour is as follows. That is, as described above, the purpose of controlling the surface of the roughened copper foil on the opposite side to the roughened surface by the above parameters is to make the surface of the circuit rougher when the roughening treatment by etching is performed after the circuit is formed. It becomes a smooth shape with excellent transmission characteristics. In addition, circuit formation is generally performed in a state in which the roughened copper foil and the resin base material are bonded by heat and pressure (that is, in the state of a copper foil laminate). On the other hand, the state of the crystals constituting the copper foil may change according to the heat load. Therefore, by performing the analysis by EBSD after heating the roughening process copper foil under the said conditions, crystal grains can be evaluated in the state similar to immediately before performing the roughening process by etching.

The thickness of the roughened copper foil is not particularly limited, preferably 0.1 μm to 210 μm, more preferably 0.3 μm to 105 μm, further preferably 7 μm to 70 μm, especially preferably 15 μm to 20 μm or less. Furthermore, the roughened copper foil of the present invention is not limited to those roughened on the surface of ordinary copper foils, and may also be roughened or micro-roughened on the surface of copper foil with a carrier. processor.

The roughened copper foil of the present invention can be well produced by performing roughening treatment on a smooth copper foil surface (for example, an electrode surface of an electrolytic copper foil) under required low roughening conditions, Form fine coarse particles. 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 electrode 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 the plurality of roughened particles preferably contain metal, more preferably copper. The metal constituting the roughened particles may contain unavoidable impurities caused by raw material components, forming steps, and the like. When the roughened particles contain copper, the copper may be composed of metallic copper or a copper alloy.

Electrodeposited copper foil is preferably produced by electrolytic deposition using a copper electrolytic solution from which polymer compounds such as animal glue have been removed. That is, high molecular compounds such as animal glue are easy to penetrate into the copper foil, and crystal growth caused by heat is easy to be suppressed. Therefore, by using the copper electrolytic solution from which the polymer compound has been removed, it is easy to satisfy the parameters required for the roughened copper foil of the present invention. For example, the polymer compound in the copper electrolyte can be removed by treating the copper electrolyte with activated carbon.

When the above-mentioned electrolysis is separated out, preferably by the following formula: _RN =C×U/m (wherein, _RN is the non-metallic impurity supply ratio (-), C is the non-metallic impurity concentration (g/ m ³ ), U is the liquid supply flow rate (m ³ /s), m is the copper precipitation rate (g/s)) The non-metallic impurity supply ratio R _N defined is set to 0.020 or more and 0.100 or less, and is more preferably set to 0.030 Above 0.100 below. Here, the non-metallic impurity concentration C is a value calculated from the sum of total organic carbon (TOC) and chloride ion (Cl ^- ) concentrations in the copper electrolyte, and the copper precipitation rate m is determined by the following formula: m =I×M/(n×F) (In the formula, I is the current value (A), M is the molar mass of copper (g/mol), n is the valence number of copper, and F is Faraday’s constant (C/mol )) Calculated value. If the non-metallic impurity supply ratio _RN is within the above-mentioned range, chlorine, low-molecular organic substances, and the like can be supplied within an appropriate speed range for deposition of copper foil. As a result, the roughness of the deposition surface of the electrolytic copper foil can be controlled within an appropriate range, and the parameters required for the roughened copper foil of the present invention can be easily satisfied.

Roughening treatment for forming a roughened surface can be favorably performed by forming roughening particles with copper or a copper alloy on copper foil. The copper foil before the roughening treatment may be a non-roughened copper foil, or may be 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 0.50 μm to 15.00 μm, more preferably from 0.50 μm to 2.00 μm. If it exists in the said range, it will become easy to provide the surface profile 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 containing a copper concentration of 7 g/L to 17 g/L and a sulfuric acid concentration of 50 g/L to 200 g/L. , electrolytic precipitation is carried out at 2.00 A/dm ² or more and 50 A/dm ² or less. The electrolysis is preferably performed for 0.5 seconds to 30 seconds, more preferably for 1 second to 30 seconds, and still more preferably for 1 second to 5 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, it is preferred to use the following formula: _RL = L/D _C (wherein, _RL is the solution resistance index (mm L/mol), L is the inter-electrode (anode-cathode distance (mm), D _C is the charge carrier density (mol/L)), the solution resistance index R _L defined by the solution is set to 9.0 mm・L/mol or more and 20.0 mm・L/mol or less, and it is better to set it to 11.0 Above mm・L/mol and below 17.0 mm・L/mol. By increasing the solution resistance index _RL as described above, the voltage in the entire system is increased, and the voltage at the time of the bump formation reaction is also increased. This affects the shape of the bumps, and as a result, bumps of a shape suitable for giving the surface profile required for the roughened copper foil of the present invention can be formed favorably. Furthermore, the charge carrier density _DC can be calculated by summing up the products of the respective ion concentrations and valence numbers for all the ions present in the plating solution. For example, when a solution containing copper sulfate and sulfuric acid is used as the plating solution, the charge carrier density D _C can be calculated by the following formula: Dc=[H ⁺ ]×1+[Cu ^{2 +} ]×2+[SO ₄ ^2- ]×2 (where [H ^＋ ] is the concentration of hydrogen ions in the solution (mol/L), [Cu ^{2 ＋} ] is the concentration of copper ions in the solution (mol/L), [SO ₄ ^2- ] is the sulfate ion concentration in the solution (mol/L)).

The relationship between the solution resistance index _RL and the voltage is explained as follows. First, the following formula is derived by 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). And, the specific resistance ρ is inversely proportional to the above-mentioned charge carrier density D _C . Therefore, when the current density is constant, 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 said to be an index related to the resistance of the solution.

If necessary, the roughening treatment may include the second roughening treatment of performing electrolytic deposition on the surface after the above roughening treatment (first roughening treatment) under specific conditions, and may further include the second roughening treatment on the surface after the second roughening treatment. The surface is subjected to the third roughening treatment of electrolysis under specific conditions. Regarding the preferred conditions for the second roughening treatment, the preferred conditions for the first roughening treatment described above can be directly applied.

On the other hand, for the third roughening treatment, it is preferable to use copper sulfate solution at 45 g/L to 80 g/L with a copper concentration of 65 g/L to 80 g/L and a sulfuric acid concentration of 50 g/L to 200 g/L. Electrodeposition is carried out at a temperature of 55°C to 55°C and at a temperature of 1 A/dm ² to 5 A/dm ² . This electrolysis is preferably performed for 1 second to 10 seconds, more preferably for 5 seconds to 8 seconds. Also, when electrolytically desorbing, it is preferable to set the solution resistance index R _L to 2.0 mm・L/mol or more and 9.0 mm・L/mol or less, more preferably 5.0 mm・L/mol or more to 8.0 mm・L /mol below.

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 of zinc plating treatment and zinc alloy plating treatment, and the zinc alloy plating treatment is particularly preferably 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, Co, and Mo. For example, by making the antirust treatment layer include Mo in addition to Ni and Zn, the treated surface of the roughened copper foil is more excellent in adhesion to resin, chemical resistance, and heat resistance, and it is difficult to leave etching. residue.

The ratio Ni/(Zn+Ni) of the Ni deposition amount to the Zn deposition amount and the total Ni deposition amount in zinc-nickel alloy plating is, in terms of mass ratio, preferably 0.3 to 0.9, more preferably 0.4 to 0.9 , and more preferably not less than 0.4 and not more than 0.8. Also, the total deposition amount of Zn and Ni in the zinc-nickel alloy plating is preferably 8 mg/ ^m to 160 mg/m, more preferably ¹³ mg/ ^m to 130 mg/m, and ^further Preferably it is not less than 19 mg/m ² and not more than 80 mg/m ² . On the other hand, the ratio Ni/(Zn+Ni+Mo) of the Ni deposition amount to the total amount of Zn deposition amount, Ni deposition amount, and Mo deposition amount in zinc-nickel-molybdenum alloy plating is preferably 0.20 or more in terms of mass ratio 0.80 or less, more preferably 0.25 to 0.75, still more preferably 0.30 to 0.65. In addition, the total deposition amount of Zn, Ni and Mo in zinc-nickel-molybdenum alloy plating is preferably 10 mg/ ^m2 to 200 mg/ ^m2 , more preferably 15 mg/ ^m2 to 150 mg/m2 ² or less, more preferably 20 mg/m ² or more and 90 mg/m ² or less. The respective adhesion amounts of Zn, Ni, and Mo can be calculated by dissolving a specific area (for example, 25 cm ² ) of the roughened surface of the roughened copper foil with acid, based on ICP (Inductively Coupled Plasma (Inductively Coupled Plasma) luminescence analysis method is used to analyze the concentration of each element in the obtained solution.

The antirust treatment preferably further includes chromate treatment, and this chromate treatment is more preferably performed on the surface of the plating layer containing zinc after the plating treatment using zinc. In this way, rust resistance can be further improved. A particularly preferred antirust treatment is a combination of zinc-nickel alloy plating (or zinc-nickel-molybdenum 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 silane coupling agent treated layer. Thereby, moisture resistance, chemical resistance, adhesiveness with an adhesive, etc. can be improved. The silane coupling agent treatment layer can be formed by appropriately diluting the silane coupling agent, coating and drying it. Examples of silane coupling agents include epoxy-functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane and 3-glycidyloxypropyltrimethoxysilane, or 3-amino Propyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy) Amino-functional silane coupling agents such as propyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane, or mercapto groups such as 3-mercaptopropyltrimethoxysilane Functional silane coupling agent or olefin functional silane coupling agent such as vinyltrimethoxysilane and vinylphenyltrimethoxysilane, or 3-methacryloxypropyltrimethoxysilane, 3-acryloxy Acryl functional silane coupling agents such as propyltrimethoxysilane, imidazole functional silane coupling agents such as imidazole silane, or trisyl functional silane coupling agents such as trimethoxysilane, etc.

For the above reasons, the roughened copper foil preferably has an antirust treatment layer and/or a silane coupling agent treatment layer on the roughening treatment surface, and more preferably has both the antirust treatment layer and the silane coupling agent treatment layer. In the case where an antirust treatment layer and/or a silane coupling agent treatment layer is formed on the roughened surface, each value of Sdr and Sk in this specification means that the antirust treatment layer and/or the silane coupling agent treatment layer are formed. After roughening the surface of the copper foil to measure and analyze the obtained value. Furthermore, the antirust treatment layer and the silane coupling agent treatment layer may be formed not only on the roughening treatment surface side of the roughening treatment copper foil but also on the side where the roughening treatment surface is not formed.

Copper-clad laminated board According to a preferred aspect of the present invention, a copper-clad laminated board is provided. The copper foil laminate includes a resin layer and a roughened copper foil provided on at least one surface of the resin layer. This roughened copper foil has a roughened surface on at least one side, and the roughened surface is in contact with the resin layer. The developed area ratio Sdr of the interface of the roughened surface of the roughened copper foil is 70.0% or less. In addition, when the surface of the roughened copper foil opposite to the roughened surface is analyzed by EBSD, in the observation field of view, for each crystal whose angle of deviation from the (111) plane is 20 degrees or less The average value of the ratio L/S of the calculated grain boundary length L to the occupied area S of the grains was 13.0 μm/μm ² or less. According to this copper foil laminated board, excellent transmission characteristics can be realized as described above.

The resin layer included in the copper foil laminate includes resin, preferably insulating resin. The resin layer is preferably a prepreg and/or a resin sheet. Prepreg system is a general term for composite materials made by impregnating synthetic resin boards, glass boards, glass woven fabrics, glass non-woven fabrics, paper and other substrates with synthetic resins. Preferable examples of insulating resins include epoxy resins, cyanate resins, bismaleimide tristannium resins (BT resins), polyphenylene ether resins, and phenol resins. Moreover, examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resins, polyimide resins, and polyester resins. In addition, from the viewpoint of improving insulation, etc., filler particles including various inorganic particles such as silica and alumina 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 through the primer resin layer coated on the surface of the copper foil in advance.

The developed area ratio Sdr of the interface on the roughened surface of the roughened copper foil of the copper foil laminate is 70.0% or less, preferably 5.0% to 60.0%, more preferably 10.0% to 50.0%, More preferably, it is 20.0% or more and 45.0% or less. Furthermore, the step difference Sk of the core portion of the roughened surface of the roughened copper foil is preferably 1.70 μm or less, more preferably 0.10 μm or more and 1.50 μm or less, further preferably 0.50 μm or more and 1.40 μm or less, and especially preferably 0.90 μm or more and 1.20 μm or less.

The average value of L/S of the roughened copper foil on the side opposite to the roughened surface is 13.0 μm/μm ² or less, preferably 2.0 μm/μm ² or more and 11.0 μm/μm ² or less, more preferably 3.0 μm/μm ² to 10.0 μm/μm ² , more preferably 5.0 μm/μm ² to 9.0 μm/μm ² . In addition, when the surface of the roughened copper foil opposite to the roughened surface is analyzed by EBSD, in the observation field of view, the angle of deviation from the (111) plane is 20 degrees or less. The total occupied area A ₁ is relative to the total occupied area A ₂ of crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, and the total occupied area of crystal grains whose angle of deviation from the (010) plane is 20 degrees or less A ₃ , and the ratio A ₁ /(A ₂ +A ₃ +A ₄ ) of the sum (A ₂ +A ₃ +A ₄ ) of the total occupied area A ₄ of grains whose angle of deviation from the (001) plane is 20 degrees or less Preferably, it is not less than 0.10 and not more than 0.60, more preferably not less than 0.15 and not more than 0.55, still more preferably not less than 0.20 and not more than 0.50.

Typically, the roughened copper foil of the present invention is used as it is as the roughened copper foil included in the copper foil laminate. Therefore, the preferred aspect of the roughened copper foil of the present invention can be directly used as a preferred aspect of the roughened copper foil of the copper foil laminate. However, the roughened copper foil included in the copper-clad laminate should only satisfy the above parameters, and the roughened copper foil of the present invention can be appropriately changed.

The manufacturing method of a printed wiring board It is preferable that the roughened copper foil of this invention or a copper foil laminated board is used for manufacturing a printed wiring board. That is, according to a preferable aspect of this invention, the manufacturing method of a printed wiring board is provided. The method includes the following steps: (1) preparation of roughened copper foil, (2) fabrication of copper foil laminate, (3) formation of circuit, (4) roughening by etching, and (5) visual inspection. Lamination of resin that needs to be carried out. Hereinafter, each of steps (1) to (5) will be described with reference to FIGS. 4 and 5 .

(1) Preparation of roughened copper foil As shown in FIG. 4( i ), a roughened copper foil 10 is prepared. The roughened copper foil 10 has the roughened surface 10a on at least one side. The developed area ratio Sdr of the interface of the roughened surface 10a is 70.0% or less, preferably 5.0% to 60.0%, more preferably 10.0% to 50.0%, further preferably 20.0% to 45.0%. If the Sdr is within the above range, high adhesion to the resin layer described below will be ensured, and a shape rich in concavo-convexities for realizing excellent transmission characteristics will be obtained.

The step difference Sk of the core portion of the roughened surface 10a of the roughened copper foil 10 is preferably 1.70 μm or less, more preferably 0.10 μm or more and 1.50 μm or less, further preferably 0.50 μm or more and 1.40 μm or less, and especially preferably 0.90 μm or more and 1.20 μm or less.

(2) Production of copper foil laminates As shown in FIG. 4(ii), the prepared roughened copper foil 10 is laminated on at least one surface of the resin layer 12 so that the roughened surface 10a is in contact with the resin layer 12 . In this way, the copper foil laminated board 14 is produced.

Lamination of the roughened copper foil 10 and the resin layer 12 is preferably performed by hot pressing. The heat load conditions (temperature, time, etc.) of hot pressing are not particularly limited as long as they are appropriately determined according to the type of resin. A preferred aspect of the resin layer 12 is as described above for the copper foil laminated board.

(3) Formation of circuit As shown in FIG. 4(iii), the roughened copper foil 10 of the copper foil laminate 14 is processed to form a circuit 16 . Processing of the roughened copper foil 10 is not particularly limited as long as it is performed based on a known method. For example, methods such as subtractive method, semi-additive method (SAP), modified semi-additive method (MSAP) and the like can be used to form the circuit 16 with a specific pattern.

When the surface of the circuit 16 before the following roughening treatment by etching is analyzed by EBSD, it is calculated for each crystal grain whose angle of deviation from the (111) plane is 20 degrees or less in the observation field of view. The average value of the ratio L/S of the grain boundary length L to the occupied area S is 13.0 μm/μm ² or less, preferably 2.0 μm/μm ² or more and 11.0 μm/μm ² or less, more preferably 3.0 μm/μm ² or more 10.0 μm/μm ² or less, more preferably 5.0 μm/μm ² or more and 9.0 μm/μm ² or less. If the average value of L/S is within the above range, the surface shape of the circuit 16 after the etching process becomes smooth, and excellent transmission characteristics can be realized.

When the surface of the circuit 16 is analyzed by EBSD before performing the following roughening treatment by etching, the total occupied area of crystal grains whose angle of deviation from the (111) plane is 20 degrees or less in the observation field of view A ₁ is relative to the total occupied area A ₂ of the crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, the total occupied area A ₃ of the crystal grains whose angle of deviation from the (010) plane is 20 degrees or less, And the ratio A ₁ /(A ₂ +A ₃ +A ₄ ) of the sum (A ₂ +A ₃ +A ₄ ) of the total occupied area A ₄ of grains whose angle of deviation from the (001) plane is 20 degrees or less is preferably 0.10 It is not less than 0.60, more preferably not less than 0.15 and not more than 0.55, and still more preferably not less than 0.20 and not more than 0.50.

(4) Roughening treatment by etching As shown in FIG. 5(iv), the circuit 16 is roughened by etching. In this way, the roughened shape 16a is given to the surface of the circuit 16 . Thereby, the reliability (adhesiveness, heat resistance, etc.) of the circuit 16 and the surrounding resin can be improved when the resins described below are laminated.

Roughening by etching is preferably performed by partially etching the surface of the circuit 16 . Etching is not particularly limited as long as it is performed based on a known method. As a representative etchant, a solution containing sulfuric acid and hydrogen peroxide, a solution containing sodium persulfate, and the like may, for example, be mentioned. In addition, these liquids may contain additives for the purpose of controlling the roughened shape by etching, stabilizing the etching rate, and the like.

(5) Lamination of resin (any step) Optionally, as shown in FIG. 5( v ), the resin layer 12 ′ can be further laminated so as to cover the circuit 16 processed by etching. In this way, the circuit 16 can be used as an inner layer circuit. The material and/or thickness of the resin layer 12' may be the same as that of the resin layer 12, or may be different.

Optionally, circuits and resin layers may be alternately formed on the resin layer 12' to form a multilayer wiring board. Moreover, in addition to the above-mentioned steps, the method of the present invention may appropriately add known processes commonly used in printed wiring boards. [Example]

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

Examples 1-5 The manufacture of the roughening process copper foil of this invention was performed as follows.

(1) Manufacture of electrolytic copper foil A sulfuric acid copper sulfate solution with a copper concentration of 80 g/L and a sulfuric acid concentration of 300 g/L was prepared as a copper electrolyte. Activated carbon treatment was performed on 1 L of the sulfuric acid acidic copper sulfate solution by contacting about 3.0 g of activated carbon for about 20 seconds. Thereafter, only in Example 4, animal glue was added to the copper electrolytic solution so that the concentration became 5 ppm. Use the copper electrolyte after activated carbon treatment (Example 1-3 and 5) or after adding animal glue (Example 4), use titanium electrode as the cathode, and use DSA (dimensionally stable anode) as the anode. 40 A/dm ² to 100 A/dm ² , and the conditions of the non-metallic impurity supply ratio shown in Table 1 were electrolyzed to obtain an electrolytic copper foil with a thickness of 18 μm.

(2) Coarsening treatment Roughening treatment was performed on the electrode surface side among the electrode surface and the deposition surface included in the above-mentioned electrolytic copper foil. The roughening process is shown in Table 1. In Example 1, it was set as a two-stage roughening process (the first roughening process and the second roughening process), and in Examples 2 and 4, it was set as one stage. The roughening treatment (first roughening treatment) in Examples 3 and 5 was set as three-stage roughening treatment (first roughening treatment, second roughening treatment, and third roughening treatment).

Conditions of roughening in each stage are as follows. -The first roughening treatment is carried out in the following manner, that is, 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 Below, liquid temperature: 30°C), electrolysis was carried out under the conditions of solution resistance index, current density and time shown in Table 1, and water washing was carried out. - The second roughening treatment is carried out in the following manner, that is, in the copper electrolytic solution for roughening treatment with the same composition as the first roughening treatment, under the conditions of solution resistance index, current density and time shown in Table 1 Under electrolysis, and washed with water. -The third roughening treatment is carried out in the following manner, that is, in the 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 Below, liquid temperature: 45°C), electrolysis was carried out under the conditions of solution resistance index, current density and time shown in Table 1, and water washing was carried out.

(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, in Examples 1 to 4, a pyrophosphoric acid bath was used on the roughened surface of the electrolytic copper foil, and the concentration of potassium pyrophosphate was 100 g/L, the concentration of zinc was 1 g/L, and the concentration of nickel was 2 Antirust treatment A (zinc-nickel-molybdenum system antirust treatment) was carried out under the conditions of g/L, molybdenum concentration 1 g/L, liquid temperature 40°C, and current density 0.5 A/dm ² . Also, use a pyrophosphoric acid bath on the surface of the electrolytic copper foil that has not been roughened, and set the concentration of potassium pyrophosphate to 80 g/L, the concentration of zinc to 0.2 g/L, the concentration of nickel to 2 g/L, the liquid temperature to 40°C, and the current Density 0.5 A/dm ² Anti-rust treatment B (zinc-nickel system anti-rust treatment). On the other hand, in Example 5, antirust treatment B was performed on both surfaces of the electrodeposited copper foil under the same conditions as those of the surface of the electrodeposited copper foil in Examples 1 to 4 that were not subjected to the roughening treatment.

(4) Chromate treatment Chromate treatment was performed on both sides of the electrolytic copper foil subjected to the above antirust treatment, and a chromate layer was 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 The chromate-treated copper foil was washed with water, and then immediately treated with a silane coupling agent, so that the silane coupling agent was adsorbed on the chromate layer on the roughened surface. The silane coupling agent treatment is carried out by spraying a solution of a silane coupling agent using pure water as a solvent to the roughened surface for adsorption treatment. 3-Aminopropyltrimethoxysilane was used as the silane coupling agent, and its concentration was set at 3 g/L. After the silane coupling agent is adsorbed, the water is finally evaporated by an electric heater to obtain a roughened copper foil with a specific thickness.

[Table 1] Table 1 Electrolytic copper foil Coarsening Anti-rust treatment Processing surface first coarsening second coarsening third roughening Glue Concentration of Electrolyte (ppm) Supply ratio of non-metallic impurities (-) Solution resistance index (mm L/mol) Current density (A/dm ² ) time(s) Solution resistance index Current density (A/dm ² ) time(s) Solution resistance index (mm L/mol) Current density (A/dm ² ) time(s) type example 1 - 0.045 electrode surface 14.2 5.6 2.7 14.2 16.9 2.7 - - - A Example 2 - 0.072 electrode surface 14.2 33.9 2.7 - - - - - - A Example 3 - 0.090 electrode surface 14.2 16.4 3.2 14.2 27.4 3.2 6.2 4.2 6.5 A Example 4* 5 0.111 electrode surface 14.2 5.6 2.7 - - - - - - A Example 5* - 0.097 electrode surface 8.1 34.0 2.7 7.3 28.5 2.7 6.2 23.1 9.1 B * indicates a comparative example.

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

(a) EBSD measurement The roughened copper foil was heated at 180°C for 1 hour, and it was set as a copper foil sample for EBSD measurement. This copper foil sample was fixed using a specific jig so that the surface (henceforth "non-processed surface") on the opposite side to the roughening process surface became the outside. Thereafter, from the non-treated surface of the copper foil sample, plane polishing using a cross-section polisher (CP) was carried out. This plane polishing was carried out under the conditions of an accelerating voltage of 6 kV and an inclination angle of 5°. Then, the surface on the non-treated side of the copper foil sample after plane polishing for 10 minutes (corresponding to a thickness of 500 nm) was set as the outermost surface, and marking and FIB (Focused Ion Beam, Focused Ion Beam) marking processing was performed. In addition, according to the roughness of the copper foil surface, it is also possible to perform planar polishing by changing conditions appropriately to the extent that the following EBSD measurement can be performed. Here, "capable of EBSD measurement" means that the hit rate in EBSD measurement is 70% or more. The hit rate refers to the ratio of the area that can be measured by the electron beam accurately hitting the surface of the sample among the total area of the sample. The hit rate of over 70% means that when using a scanning electron microscope to observe, the electron beam hits the entire copper foil surface as a whole, resulting in accurate EBSD data.

For the surface of the copper foil sample after plane grinding, use a FE (Field Emission, field emission) gun-type scanning electron microscope (manufactured by Carl Zeiss Co., Ltd., Crossbeam540) equipped with an EBSD detector (manufactured by Oxford Instruments, Symmetry) observe. Then, EBSD data were obtained using EBSD measurement software (manufactured by Oxford Instruments, AZtec5.0 HF1), and the obtained EBSD data were converted into an OIM (Orientation Imaging Microscopy, orientation imaging microscopy) format. The measurement conditions of the scanning electron microscope at the time of observation are as follows. In addition, the measurement magnification is a magnification at which the number of particles (crystal grains) detected in the field of view is 700 or more among 1000 times and 3000 times, and a magnification as high as possible is selected. ＜Scanning Electron Microscope Measurement Conditions＞ - Accelerating voltage: 15 kV - Step size: 0.2 μm (magnification 1000 times) or 60 nm (magnification 3000 times) - Area width: 90 μm (magnification 1000 times) or 30 μm (magnification 3000 times) - Area height: 78.6 μm (1000x magnification) or 26 μm (3000x magnification) - Scan phase: Cu - Specimen angle: 70°

For the above-mentioned EBSD data converted into OIM format, using the crystal diameter calculation software (manufactured by AMETEK, OIM Analysis v7.3.1 x64), the azimuth difference of 5° or more was regarded as a grain boundary, thereby identifying each crystal. However, since the crystal structure of copper is a cubic crystal structure, considering the twin grain boundary, it is not regarded as a grain boundary in the case of the following (i) or (ii). (i) The twin grain boundary in the azimuth relationship rotated 60° around the <111> axis (ii) The twin grain boundary in the azimuth relationship of rotating 38.9° around the <110> axis

Then, use the above-mentioned crystal diameter calculation software, set the coordinates so that the z-axis is perpendicular to the surface of the copper foil sample, and output the following data. -Average orientation (average orientation phi(ϕ1), PHI(Φ), phi(ϕ2)) -Area of grain (particle area S) -Grain circularity (the true circularity R of particle shape)

算出各粒子之晶界長度(周長)L，且基於下述式分別算出各粒子朝向銅箔樣品表面之結晶面之法向量(h，k，l)。 h＝sinΦ×sinϕ2 k＝-sinΦ×cosϕ2 l＝cosΦ Use the output data, based on the following formula: [numeral 1]

The grain boundary length (circumference length) L of each particle was calculated, and the normal vector (h, k, l) of each particle toward the crystal plane of the surface of the copper foil sample was calculated based on the following formula. h＝sinΦ×sinϕ2 k＝-sinΦ×cosϕ2 l＝cosΦ

算出所算出之各粒子之結晶面之法向量(h，k，l)與基準面(u，v，w)之法向量所成之角，獲得自基準面偏移之角度θ。此處，於以此方式計算之θ值為90度以上且未達180度之情形時，採用從180度減去該值所得之值作為最終之θ值。例如，於藉由上述式計算出θ為150度之情形時，採用從180度減去150度所得之30度作為最終之θ值。如此，分別特定出自(111)面偏移之角度為20度以下之粒子、自(100)面偏移之角度為20度以下之粒子、自(010)面偏移之角度為20度以下之粒子、及自(001)面偏移之角度為20度以下之粒子。 Calculate the angle of deviation of each particle from the reference plane (u, v, w) as follows. First, set the target reference plane (u, v, w). For example, when calculating the angle offset from the (111) plane, set (u, v, w)=(1, 1, 1). Then, based on the following formula: [number 2]

Calculate the angle formed by the calculated normal vector (h, k, l) of the crystal plane of each particle and the normal vector of the reference plane (u, v, w) to obtain the angle θ offset from the reference plane. Here, when the θ value calculated in this way is 90 degrees or more and less than 180 degrees, the value obtained by subtracting this value from 180 degrees is adopted as the final θ value. For example, when θ is calculated as 150 degrees by the above formula, 30 degrees obtained by subtracting 150 degrees from 180 degrees is used as the final value of θ. In this way, the particles whose deviation angle from the (111) plane is 20 degrees or less, the particles whose deviation angle from the (100) plane is 20 degrees or less, and the particles whose deviation angle from the (010) plane is 20 degrees or less Particles, and particles whose angle of deviation from the (001) plane is 20 degrees or less.

For each particle whose angle of deviation from the (111) plane is 20 degrees or less, the ratio L/S of the grain boundary length (circumference length) L to the occupied area (particle area) S was obtained, and the average value was calculated. Also, calculate the total occupied area A ₁ of crystal grains whose angle of deviation from the (111) plane is 20 degrees or less relative to the total occupied area A ₂ of crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, The sum of the total occupied area A _{3 of} the crystal grains whose angle of deviation from the (010) plane is 20 degrees or less, and the total occupied area A ₄ of the crystal grains whose angle of deviation from the (001) plane is 20 degrees or less (A ₂ +A ₃ +A ₄ ) ratio A ₁ /(A ₂ +A ₃ +A ₄ ). The results are shown in Table 3.

(b) Measurement by laser microscopy The measurement of the roughened surface of the roughened copper foil was performed based on ISO25178 by surface roughness analysis using a laser microscope (manufactured by Olympus Co., Ltd., OLS-5000). At this time, as shown in Table 2, the measurement was performed at a measurement magnification of 200 times (objective lens magnification of 100 times×optical zoom of 2 times). Other specific measurement conditions are shown in Table 2. The surface profile of the obtained roughened surface was analyzed under the conditions shown in Table 2, and Sdr and Sk were calculated. The results are shown in Table 3.

[Table 2] Table 2 Measurement conditions Laser Microscope Model Made by Olympus Co., Ltd., OLS-5000 Objective lens magnification 100 times optical zoom 2 times viewing direction Copper foil processing stripes and the direction perpendicular to the field of view test methods Designate multiple area modes, and in lattice registration mode, specify X=2, Y=2 for "matrix", specify X=64 μm, Y=64 μm for "pitch", and measure 2×2 adjacent areas (64 μm×64 μm each) Analytical conditions Object area 64.419 μm in length × 64.397 μm in width standard ISO25178 plane tilt correction Implemented by "automatically" F-calculus Set the Shape Removal Method to Multidimensional Surface and the Dimension to 1D. S filter none L filter 5 μm (in the case of Sdr) or none (in the case of Sk) average method Average the measured values at 2×2 points measured at the same time

(c) Transfer characteristics A base material for high frequency (manufactured by Panasonic, MEGTRON 6N) 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. Hot pressing was performed to obtain a copper foil laminate with an insulation thickness of 136 μm. One surface of the obtained copper foil laminate was etched to obtain a circuit board on which a circuit was formed. The circuit of the circuit board is roughened using an etchant mainly composed of sulfuric acid-hydrogen peroxide. This roughening process was performed by applying the etching conditions in which the average amount of reduction of the thickness of copper in Example 4 was 1.5 micrometers to all Examples 1-5. The above-mentioned insulating resin base material was laminated on the circuit side surface of the roughened circuit board, and hot-pressed using a vacuum press at a temperature of 190° C. and a pressing time of 120 minutes. In this way, a substrate for measurement of transmission loss having a total insulation thickness (portion without circuits) of 254 μm and a strip line having a characteristic impedance of 50 Ω was obtained. With respect to the obtained substrate for measurement of transmission loss, the transmission loss (dB/cm) at 50 GHz was measured using a network analyzer (manufactured by Keysight Technologies, N5225B). The quality of the obtained transmission loss was evaluated according to the following criteria. The results are shown in Table 3. <Evaluation criteria for transmission loss> - Good: Transmission loss is -0.55 dB/cm or more - Poor: transmission loss does not reach -0.55 dB/cm

[table 3] table 3 Parameters of roughening copper foil performance roughened surface The face on the opposite side from the roughened face transmission characteristics Sdr (%) Sk (μm) Average value of L/S (μm/μm ² ) A1/(A2+A3+A4) Transmission loss at 50 GHz (dB/cm) example 1 22.8 1.16 7.1 0.26 -0.55 Example 2 40.4 1.19 8.2 0.31 -0.54 Example 3 63.1 1.56 6.2 0.46 -0.55 Example 4* 21.3 0.97 14.3 0.62 -0.58 Example 5* 92.3 1.89 7.6 0.35 -0.67 * indicates a comparative example.

Fig. 1 is a diagram for explaining the load curve and load area ratio Smr(c) of a surface determined in accordance with ISO25178. FIG. 2 is a diagram for explaining the level difference Sk of the core part determined based on ISO25178. Fig. 3 is a diagram for explaining that the surface irregularities of the roughened copper foil include a roughened particle component and a waviness component. Fig. 4 is a flowchart showing an example of the method of manufacturing a printed wiring board in the present invention, and is a diagram showing an initial step (steps (i) to (iii)). Fig. 5 is a flow chart showing an example of the method of manufacturing a printed wiring board in the present invention, and is a diagram showing subsequent steps (steps (iv) to (v)) following the steps shown in Fig. 4 .

Claims (10)

A roughened copper foil, which has a roughened surface on at least one side, the above-mentioned roughened surface is measured under the conditions of 200 times magnification, no S filter, and 5 μm L filter according to ISO25178 The developed area ratio Sdr of the obtained interface is 70.0% or less, and the surface opposite to the above-mentioned roughened surface is analyzed by electron beam backscattering diffraction (EBSD) after heating at 180°C for 1 hour , in the observed field of view, the average value of the ratio L/S of the grain boundary length L to the occupied area S calculated for each grain with an angle of deviation from the (111) plane of 20 degrees or less is 13.0 μm/μm ² the following. The roughened copper foil according to claim 1, wherein the surface opposite to the roughened surface is in the observation field of view, and the total occupied area of crystal grains whose angle of deviation from the (111) plane is 20 degrees or less A ₁ is relative to the total occupied area A ₂ of the crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, the total occupied area A ₃ of the crystal grains whose angle of deviation from the (010) plane is 20 degrees or less, And the ratio A ₁ /(A ₂ +A ₃ +A ₄ ) of the sum of the total occupied area A ₄ (A ₂ +A ₃ +A ₄ ) of crystal grains whose angle of deviation from the (001) plane is 20 degrees or less is 0.10 or more 0.60 the following. The roughened copper foil according to claim 1 or 2, wherein the average value of the above-mentioned L/S is not less than 2.0 μm/μm 2 and not ^more than 11.0 μm/μm ² . The roughened copper foil according to claim 1 or 2, wherein the above-mentioned roughened surface is based on ISO25178, and the level difference Sk of the core part is measured at a magnification of 200 times, without an S filter, and without an L filter. 1.70 μm or less. 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 electrode side of the electrolytic copper foil. The roughened copper foil according to claim 1 or 2, wherein the roughened surface has a plurality of roughened particles, and the roughened particles include metal. A copper foil laminate comprising a resin layer and a roughened copper foil provided on at least one surface of the resin layer, wherein the roughened copper foil has a roughened surface on at least one side, and the roughened The surface is in contact with the above-mentioned resin layer, and the above-mentioned roughened surface is based on ISO25178, and the developed area ratio Sdr of the interface measured under the conditions of 200 times magnification, no S filter, and L filter 5 μm is 70.0% or less , and the surface of the above-mentioned roughened copper foil opposite to the above-mentioned roughened surface is analyzed by the electron beam backscatter diffraction method (EBSD), in the observation field of view, from (111) The average value of the ratio L/S of the calculated grain boundary length L to the occupied area S of each crystal grain whose plane deviation angle is 20 degrees or less is 13.0 μm/μm ² or less. The copper foil laminated board according to claim 7, wherein the surface of the roughened copper foil opposite to the roughened surface is within the observation field of view, and the angle of deviation from the (111) plane is 20 degrees or less The total occupied area A ₁ of crystal grains is relative to the total occupied area A ₂ of crystal grains whose angle of deviation from the (100) plane is 20 degrees or less, and the total occupied area of crystal grains whose angle of deviation from the (010) plane is 20 degrees or less The ratio A ₁ /(A 2 +A 3 +A _{) of the sum of the total occupied area A 3 and the total occupied area A 4 of crystal grains whose angle of deviation from the (001) plane is 20 degrees or less (A 2 + A 3 + A 4} ) ₄ ) Not less than 0.10 and not more than 0.60. A method of manufacturing a printed wiring board, which includes the following steps: preparing a roughened copper foil, the roughened copper foil has a roughened surface on at least one side, and the roughened surface is based on ISO25178 at a magnification of 200 times , without S filter, and under the conditions of L filter 5 μm, the expansion area ratio Sdr of the interface measured is 70.0% or less; the above roughened copper foil is treated with the above roughened treatment on at least one surface of the resin layer lamination in such a way as to be in contact with the above-mentioned resin layer to produce a copper foil laminate; processing the above-mentioned roughened copper foil of the above-mentioned copper-clad laminate to form a circuit; and performing roughening treatment on the above-mentioned circuit by etching; and performing When the surface of the above-mentioned circuit before roughening treatment by etching is analyzed by electron beam backscatter diffraction (EBSD), the angle of deviation from the (111) plane is 20 in the observation field of view. The average value of the ratio L/S of the grain boundary length L to the occupied area S calculated for each crystal grain below 13.0 μm/μm 2 is 13.0 μm/μm ² or less. The method of manufacturing a printed wiring board according to claim 9, wherein the surface of the circuit before the roughening treatment by etching is a crystal grain whose angle of deviation from the (111) plane is 20 degrees or less in the observation field of view The total occupied area A ₁ is relative to the total occupied area A ₂ of crystal grains whose angle of deviation from (100) plane is less than 20 degrees, and the total occupied area of crystal grains whose angle of deviation from (010) plane is less than 20 degrees The ratio A ₁ /(A 2 +A ₃ +A _{4 )} of the sum (A ₂ +A ₃ +A ₄ ) of the area A 3 and the total occupied area _{A 4} of the crystal grains whose angle of deviation from the (001) plane is 20 degrees or less It is not less than 0.10 and not more than 0.60.

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