JP6945523B2 - Surface-treated copper foil, copper foil with carrier, and methods for manufacturing copper-clad laminates and printed wiring boards using them. - Google Patents

Description

It relates to a surface-treated copper foil, a copper foil with a carrier, and a method for manufacturing a copper-clad laminate and a printed wiring board using them.

In recent years, the semi-additive method (SAP method) has been widely adopted as a method for manufacturing a printed wiring board suitable for circuit miniaturization. The SAP method is a method suitable for forming an extremely fine circuit, and as an example thereof, a roughened copper foil with a carrier is used. For example, as shown in FIGS. 1 and 2, an ultrathin copper foil 10 having a roughened surface is used, and a prepreg 12 and a primer layer 13 are used on an insulating resin substrate 11 having a lower layer circuit 11b on a base material 11a. (Step (a)), the carrier (not shown) is peeled off, and then a via hole 14 is formed by laser perforation if necessary (step (b)). Next, the ultrathin copper foil is removed by etching to expose the primer layer 13 to which the roughened surface profile is imparted (step (c)). After electroless copper plating 15 is applied to the roughened surface (step (d)), masking is performed in a predetermined pattern by exposure and development using a dry film 16 (step (e)), and electrolytic copper plating 17 is applied. (Step (f)). After the dry film 16 was removed to form the wiring portion 17a (step (g)), the unnecessary electroless copper plating 15 between the adjacent wiring portions 17a and 17a was removed by etching (step (h)). A wiring 18 formed in a predetermined pattern is obtained.

In the SAP method using the roughened copper foil as described above, the roughened copper foil itself is removed by etching after laser drilling (step (c)). Then, since the uneven shape of the roughened surface of the roughened copper foil is transferred to the surface of the laminate from which the roughened copper foil has been removed, the insulating layer (for example, the primer layer 13 or it) is transferred in the subsequent steps. If not, the adhesion between the prepreg 12) and the plating circuit (for example, the wiring 18) can be ensured. Although the modified semi-additive method (MSAP method) in which the copper foil removing step corresponding to the step (c) is not performed is also widely adopted, the copper foil is used in the etching step (corresponding to the step (h)) after removing the dry film. Since the two layers, the layer and the electroless copper plating layer, must be removed by etching, it is necessary to perform etching deeper than the SAP method, which requires only one layer of the electroless copper plating layer to be removed by etching. Therefore, it can be said that the MSAP method is somewhat inferior to the SAP method in terms of fine circuit formability because it is necessary to narrow the circuit space somewhat in consideration of a larger amount of etching. That is, the SAP method is more advantageous for the purpose of forming a finer circuit.

On the other hand, a roughened copper foil with a carrier that controls the shape of the roughened particles is known. For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2013-199082), the average diameter D1 of the particle root at a position of 10% of the particle length is 0.2 μm to 1.0 μm on the surface of the ultrathin copper layer. A copper foil with a carrier is disclosed, which comprises a roughened layer having a ratio L1 / D1 of a particle length L1 to an average diameter D1 at a particle root of 15 or less. In Patent Document 1, the ratio D2 / D1 of the average diameter D2 of the center of the particle at the position of 50% of the particle length to the average diameter D1 of the particle root is 1 to 4 on the surface of the ultrathin copper layer, and the particles. It is said that the ratio D2 / D3 of the particle tip D3 at the position of 90% of the particle length to the average diameter D2 in the center is preferably 0.8 to 1.0. Further, in the examples of Patent Document 1, it is disclosed that the length of the roughened particles is 2.68 μm or more.

Japanese Unexamined Patent Publication No. 2013-199082

In the SAP method using the roughened copper foil as described above, the roughened copper foil itself is removed by etching after laser drilling (step (c)). Then, as a result of transferring the uneven shape of the roughened surface of the roughened copper foil to the surface of the laminate from which the roughened copper foil has been removed, a replica uneven shape is obtained. By doing so, the adhesion between the insulating layer (for example, the primer layer 13 or the prepreg 12 in the absence thereof) and the plating circuit (for example, the wiring 18) can be ensured in the subsequent steps. However, further improvement in adhesion is desired in order to cope with further miniaturization of circuits. Therefore, by making the uneven shape of the roughened surface a shape provided with substantially spherical protrusions having a constriction, the adhesion is improved by utilizing the anchor effect due to the biting into the constricted concave portion of the corresponding replica uneven shape. It is conceivable to plan. However, in this case, during the electroless copper plating in the step (d), the concave portion of the replica uneven shape may be buried by the copper plating, or the constricted portion of the replica uneven shape may be closed by the copper plating and flattened. The burial or flattening of such a replica uneven shape causes a decrease in dry film resolution and etching property. That is, as a result of reducing the biting of the dry film into the uneven shape of the replica, the adhesion to the dry film is lowered and the resolution of the dry film is lowered. In addition, since electroless copper plating fills the constricted recesses of the replica uneven shape, more etching is required to eliminate residual copper.

The present inventors have now applied to the treated surface of the surface-treated copper foil for the SAP method by imparting a unique surface profile defined by the arithmetic average curve Spc of the peak peak measured in accordance with ISO25178. It was found that a surface-treated copper foil capable of imparting a surface profile excellent not only in excellent plating circuit adhesion but also in etching property to electroless copper plating to a laminate can be provided. It was also found that by using the surface-treated copper foil, extremely fine dry film resolution can be realized in the dry film developing process in the SAP method.

Therefore, an object of the present invention is that when used in the SAP method, it is possible to impart a surface profile excellent not only in adhesion to the plating circuit but also in etching property to electroless copper plating and dry film resolution to the laminate. The purpose is to provide surface-treated copper foil. Another object of the present invention is to provide a copper foil with a carrier provided with such a surface-treated copper foil.

According to one aspect of the present invention, a surface-treated copper foil having a treated surface on at least one side.
The treated surface has an arithmetic mean song Spc of the peak peak measured in accordance with ISO25178 of 55 mm ^-1 or more.
When a resin film is thermocompression bonded to the treated surface to transfer the surface shape of the treated surface to the surface of the resin film and the surface-treated copper foil is removed by etching, the surface of the resin film remains. , A surface-treated copper foil having a peak arithmetic average Spc of 55 mm ^{-1 or more measured in accordance with ISO25178 is provided.}

According to another aspect of the present invention, the carrier, the peeling layer provided on the carrier, and the surface-treated copper foil provided on the peeling layer with the treated surface facing outward are provided. Copper foil with a carrier is provided.

According to another aspect of the present invention, there is provided a method for producing a copper-clad laminate, which comprises producing a copper-clad laminate using the surface-treated copper foil or the carrier-attached copper foil.

According to another aspect of the present invention, there is provided a method for manufacturing a printed wiring board, which comprises manufacturing the printed wiring board using the surface-treated copper foil or the copper foil with a carrier.

It is a process flow chart for demonstrating the SAP method, and is the figure which shows the process (steps (a)-(d)) of the first half. It is a process flow chart for demonstrating the SAP method, and is the figure which shows the process (step (e)-(h)) of the latter half. It is a figure for demonstrating the load curve and the load area ratio determined in accordance with ISO25178. It is a figure for demonstrating the load area ratio Smr1 which separates a protruding mountain part and a core part determined in accordance with ISO25178.

Definitions Definitions of terms or parameters used to identify the present invention are shown below.

In the present specification, the "arithmetic mean song Spc of the peak peak" is a parameter representing the arithmetic mean of the principal curvature of the peak peak of the surface, which is measured according to ISO25178. A small value indicates that the points of contact with other objects are rounded. On the other hand, a large value indicates that the point of contact with another object is sharp. In short, the arithmetic mean song Spc at the peak can be said to be a parameter representing the roundness of the hump, which can be measured with a laser microscope. The arithmetic mean curve Spc at the peak can be calculated by measuring the surface profile of a predetermined measurement area (for example, ^{a two-dimensional region of 100 μm 2) on the treated surface with a commercially available laser microscope.} Spc is defined by the following formula.

In the present specification, the "surface load curve" (hereinafter, simply referred to as "load curve") is a curve representing the height at which the load area ratio is 0% to 100%, which is measured in accordance with ISO25178. say. As shown in FIG. 3, the load area ratio is a parameter representing the area of a region having a certain height c or more. The load area ratio at the height c corresponds to Smr (c) in FIG. As shown in FIG. 4, the secant line of the load curve drawn from the load area ratio of 0% along the load curve with the difference of the load area ratio set to 40% is moved from the load area ratio of 0%, and the secant line is used. The position where the slope is the gentlest is called the central part of the load curve. The straight line that minimizes the sum of squares of the deviations in the vertical axis direction with respect to this central portion is called an equivalent straight line. The portion included in the height range of the load area ratio of the equivalent straight line from 0% to 100% is called the core portion. The part higher than the core part is called the protruding peak part, and the part lower than the core part is called the protruding valley part. The core portion represents the height of the area that comes into contact with other objects after the initial wear is completed.

In the present specification, the “load area ratio Smr1 that separates the protruding mountain portion and the core portion” is the intersection of the height of the upper part of the core portion and the load curve, which is measured in accordance with ISO25178, as shown in FIG. It is a parameter representing the load area ratio (that is, the load area ratio that separates the core portion and the protruding mountain portion). The larger this value is, the larger the proportion of the protruding mountain portion is. In FIG. 4, Sk represents the height of the core portion, and Smr2 represents the load area ratio that separates the core portion and the protruding valley portion. The load area ratio Smr1 that separates the protruding peak portion and the core portion can be calculated by measuring the surface profile ^{of a predetermined measurement area (for example, a region of 100 μm 2) on the treated surface with a commercially available laser microscope.}

In the present specification, the “mountain apex density Spd” is a parameter representing the number of mountain vertices per unit area measured in accordance with ISO25178. A large value suggests that the number of contact points with other objects is large. The peak density Spd of the peak can be calculated by measuring the surface profile of a predetermined measurement area (for example, ^{a region of 100 μm 2) on the treated surface with a commercially available laser microscope.}

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

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

Surface-treated copper foil The copper foil according to the present invention is a surface-treated copper foil. This surface-treated copper foil has a treated surface on at least one side. This treated surface has an arithmetic mean song Spc of the peak peak measured according to ISO25178 of 55 mm ^-1 or more. Further, this surface-treated copper foil is a resin film left when the surface-treated copper foil is thermocompression-bonded to the treated surface to transfer the surface shape of the treated surface to the surface of the resin film and the surface-treated copper foil is removed by etching. On the surface (hereinafter, also referred to as a transfer surface) of the surface (hereinafter, also referred to as a resin replica), the arithmetic average curve Spc of the peak peak measured in accordance with ISO25178 is 55 mm ^-1 or more. In this way, by imparting a unique surface profile defined by the arithmetic average curve Spc of the peak peak measured in accordance with ISO25178 to the treated surface of the surface-treated copper foil, when used in the SAP method, It is possible to provide a surface-treated copper foil capable of imparting a surface profile excellent not only to excellent plating circuit adhesion but also excellent etching property to electroless copper plating to a laminate. Further, by using the surface-treated copper foil, extremely fine dry film resolution can be realized in the dry film developing step in the SAP method.

The adhesion of the plating circuit and the etching property for electroless copper plating are inherently difficult to be compatible with each other, but according to the present invention, they can be unexpectedly compatible with each other. That is, as described above, the surface profile having a constricted recess suitable for improving the adhesion to the plating circuit tends to reduce the etching property of the electroless copper plating in the step (h) of FIG. That is, since the constricted concave portion of the replica uneven shape is filled with electroless copper plating, more etching is required to eliminate the residual copper. However, according to the roughened copper foil of the present invention, it is possible to secure excellent adhesion to the plating circuit while realizing such a reduction in the amount of etching. It is considered that this is because the uneven shape without constriction is brought about by setting the Spc of the treated surface of the surface-treated copper foil and the Spc of the transfer surface of the resin replica to 55 mm ^{-1 or more, respectively.}

That is, the larger the Spc, the sharper the apex of the convex portion, and therefore, the treated surface without the constriction has a sharper apex of the convex portion, that is, the Spc is larger than the treated surface having the constriction. Regarding the transfer surface of the resin replica to which the uneven shape of the treated surface is transferred, it can be said that the larger the Spc, the sharper the apex of the convex portion. This is because the transfer surface in the case of a concavo-convex shape with a constriction has flat vertices, whereas the transfer surface in the case of a concavo-convex shape without a constriction does not have a flat apex and has a constant curvature (that is, a sharp point). Because). As a result, the transfer surface without constriction has a larger Spc than the transfer surface with constriction. That is, by increasing the Spc of the treated surface of the surface-treated copper foil and the Spc of the transfer surface of the resin replica to 55 mm ^-1 or more, respectively, a concavo-convex shape without constriction is obtained, and the above problem caused by the constricted shape is caused. It is thought that it will be resolved conveniently. That is, since there is no constriction shape, electroless copper plating can be faithfully followed the uneven shape of the treated surface and reproduced without damaging the shape, and as a result, excellent adhesion to the plating circuit can be achieved. It is considered that this can be realized without impairing the etchability for electroless copper plating. In this way, it is possible to achieve both adhesion to the plating circuit and etching property for electroless copper plating. It is considered that extremely fine dry film resolution can be realized in the dry film developing process in the SAP method by achieving both such excellent adhesion and excellent etching property for electroless copper plating. .. Therefore, the surface-treated copper foil of the present invention is preferably used for producing a printed wiring board by the SAP method. In other words, it can be said that the surface-treated copper foil of the present invention is preferably used for transferring the uneven shape to the insulating resin layer for the printed wiring board.

The surface-treated copper foil of the present invention has a treated surface on at least one side. The treated surface is a surface that has been subjected to some surface treatment, and is typically a roughened surface. In any case, the surface-treated copper foil may have a treated surface (for example, a roughened surface) on both sides, or may have a treated surface on only one side. When the treated surfaces are provided on both sides, the surface on the laser irradiation side (the surface opposite to the surface in close contact with the insulating resin) is also surface-treated when used in the SAP method, so that the laser absorption is enhanced. As a result, the laser perforation property can also be improved.

The surface-treated copper foil of the present invention has an arithmetic mean curve Spc of 55 mm ^-1 or more at the peak, preferably 60 mm ^-1 or more and 200 mm ^-1 or less, and more preferably 60 mm ^-1 or more and 150 mm ^-1 or less. be. Within such a range, it is easy to realize an uneven shape without a constriction.

The surface-treated copper foil of the present invention is a resin film remaining when a resin film is thermocompression-bonded to the treated surface to transfer the surface shape of the treated surface to the surface of the resin film and the surface-treated copper foil is removed by etching. The arithmetic average curve Spc of the peak on the surface of the resin replica (that is, the transfer surface of the resin replica) is 55 mm ^-1 or more, preferably 60 mm ^-1 or more and 200 mm ^-1 or less, more preferably 60 mm ^-1 or more and 150 mm ^-1 or less, and further. It is preferably 60 mm ^-1 or more and 130 mm ^-1 or less. Within such a range, it is easy to realize an uneven shape without a constriction. The resin film is preferably a thermosetting resin film, and may be in the form of a prepreg. Examples of the thermosetting resin include epoxy resin, cyanate resin, bismaleimide triazine resin (BT resin), polyphenylene ether resin, phenol resin, polyimide resin and the like. The thermocompression bonding is not particularly limited as long as the uneven shape of the treated surface of the surface-treated copper foil can be transferred to the resin film. For example, it is preferable to perform thermocompression bonding at a pressure of 3.0 to 5.0 MPa and a temperature of 200 to 240 ° C. for 60 to 120 minutes.

In the surface-treated copper foil of the present invention, the surface of the resin film left after the etching (that is, the transfer surface of the resin replica) has a load area ratio Smr1 of 9.0% or more that separates the protruding peak portion and the core portion. Is preferable, more preferably 10 to 20%, still more preferably 10 to 15%. Within such a range, a shape without a constriction can be more preferably defined. As described above, the larger the value of Smr1, the larger the proportion of the protruding mountain portion. In this respect, since the constricted portion of the transfer surface of the resin replica is not detected by observation with a laser microscope from above, it is recognized by the laser microscope as an equivalent of a rectangular virtual transfer surface having a rectangular recess lacking the constriction. As a result, the rate of increase in the cross-sectional area when sliced from above becomes constant immediately, that is, the protruding ridge becomes smaller, and as a result, Smr1 becomes smaller. On the other hand, the transfer surface without constriction has a larger protruding peak than the transfer surface with constriction (which is equivalent to the rectangular virtual transfer surface), and therefore Smr1 is larger. That is, the treated surface without constriction has a larger proportion of the protruding peaks than the treated surface with constriction, that is, Smr1 is larger.

According to a preferred embodiment of the present invention, a plurality of roughened particles are attached to the treated surface. That is, the treated surface is preferably a roughened surface. The roughened particles are preferably made of copper particles. The copper particles may be made of metallic copper or may be made of a copper alloy. However, when the copper particles are a copper alloy, the solubility in the copper etching solution may be lowered, or the life of the etching solution may be shortened due to the mixing of the alloy component in the copper etching solution. Therefore, the copper particles are metallic copper. It is preferably composed of.

Treated surface is preferably vertex density Spd mountain which is measured in accordance is 5000 mm ^-2 or more 20000 mm ^-2 or less in ISO25178, and more preferably 7000 mm ^-2 or more 18000Mm ^-2 or less, more preferably 10000 mm ^-2 It is 15000 mm- ² or less. Within these ranges, the anchor effect based on the uneven shape can be sufficiently exhibited, and the adhesion of the plating circuit and the resolution of the dry film are improved.

The thickness of the surface-treated copper foil of the present invention is not particularly limited, but is preferably 0.1 to 18 μm, more preferably 0.5 to 10 μm, still more preferably 0.5 to 7 μm, and particularly preferably 0.5 to 5 μm. , Most preferably 0.5 to 3 μm. The surface-treated copper foil of the present invention is not limited to the surface of a normal copper foil that has been subjected to surface treatment such as roughening treatment, but the surface treatment such as roughening treatment of the copper foil surface of a copper foil with a carrier is performed. It may be the one that went.

Method for Producing Surface-treated Copper Foil An example of a preferable method for producing the surface-treated copper foil according to the present invention will be described, but the surface-treated copper foil according to the present invention is not limited to the method described below, and the surface-treated copper foil according to the present invention is not limited to the method described below. It may be manufactured by any method as long as a surface profile can be achieved.

(1) Preparation of Copper Foil Both electrolytic copper foil and rolled copper foil can be used as the copper foil used for producing the surface-treated copper foil. The thickness of the copper foil is not particularly limited, but is preferably 0.1 to 18 μm, more preferably 0.5 to 10 μm, still more preferably 0.5 to 7 μm, particularly preferably 0.5 to 5 μm, and most preferably 0. .5 to 3 μm. When the copper foil is prepared in the form of a copper foil with a carrier, the copper foil is formed by a wet film forming method such as a non-electrolytic copper plating method and an electrolytic copper plating method, a dry film forming method such as sputtering and chemical vapor deposition, or a dry film forming method. It may be formed by a combination thereof.

(2) Surface treatment (roughening treatment)
Copper particles are used to roughen at least one surface of the copper foil. This roughening is performed by electrolysis using a copper electrolytic solution for roughening treatment. This electrolysis is preferably carried out through a two-step plating step. In the first-step plating step, a copper sulfate solution containing a copper concentration of 8 to 12 g / L and a sulfuric acid concentration of 200 to 280 g / L is used, the liquid temperature is 20 to 40 ° C., the current density is 15 to 35 A / dm ² , and the time is 5. It is preferable to carry out electrodeposition under plating conditions of ~ 25 seconds. This first-step plating step is preferably performed twice in total using two tanks. In the second-step plating step, a copper sulfate solution containing a copper concentration of 65 to 80 g / L and a sulfuric acid concentration of 200 to 280 g / L is used, the liquid temperature is 45 to 55 ° C., the current density is ^{5 to 30 A / dm 2} , and the time is 5. It is preferable to carry out electrodeposition under plating conditions of ~ 25 seconds. The amount of electricity in each step is set so that the ratio (Q ₁ / Q _{2 ) of the amount of electricity Q 1 in} the first plating step to the amount of electricity Q ₂ in the second plating step is less than 1.0. Is preferable, more preferably 0.5 to 0.9, still more preferably 0.7 to 0.9. _{By lowering Q 1} / Q ₂ in this way, it is possible to realize a roughened surface having a concavo-convex shape without constriction. Incidentally, the quantity of electricity Q ₁ when the first stage of the plating process is performed a plurality of times is the total quantity of electricity multiple steps.

(3) Rust prevention treatment If desired, the copper foil after the roughening treatment may be subjected to a rust prevention treatment. The rust preventive treatment preferably includes a plating treatment using zinc. The plating treatment using zinc may be either a zinc plating treatment or a zinc alloy plating treatment, and the zinc alloy plating treatment is particularly preferably a zinc-nickel alloy treatment. The zinc-nickel alloy treatment may be a plating treatment containing at least Ni and Zn, and may further contain other elements such as Sn, Cr, and Co. The Ni / Zn adhesion ratio in the zinc-nickel alloy plating is preferably 1.2 to 10 in terms of mass ratio, more preferably 2 to 7, and even more preferably 2.7 to 4. Further, the rust preventive treatment preferably further includes a chromate treatment, and it is more preferable that the chromate treatment is performed on the surface of the plating containing zinc after the plating treatment using zinc. By doing so, the rust prevention property can be further improved. A particularly preferable rust preventive treatment is a combination of a zinc-nickel alloy plating treatment and a subsequent chromate treatment.

(4) Treatment with Silane Coupling Agent If desired, the copper foil may be treated with a silane coupling agent to form a silane coupling agent layer. As a result, moisture resistance, chemical resistance, adhesion to an adhesive or the like can be improved. The silane coupling agent 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-glycidoxypropyltrimethoxysilane, or 3-aminopropyltriethoxysilane and N-2 (amino). Amino functions such as ethyl) 3-aminopropyltrimethoxysilane, N-3-(4- (3-aminopropoxy) butoxy) propyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane A sex silane coupling agent, or a mercapto-functional silane coupling agent such as 3-mercaptopropyltrimethoxysilane, or an olefin-functional silane coupling agent such as vinyltrimethoxysilane or vinylphenyltrimethoxysilane, or 3-methacryloxypropyl. Examples thereof include an acrylic functional silane coupling agent such as trimethoxysilane, an imidazole functional silane coupling agent such as imidazole silane, and a triazine functional silane coupling agent such as triazinesilane.

Copper Foil with Carrier The surface-treated copper foil of the present invention can be provided in the form of a copper foil with a carrier. In this case, the copper foil with a carrier is provided with the carrier, a release layer provided on the carrier, and the release layer provided on the release layer with the treated surface (typically the roughened surface) on the outside. It is equipped with a surface-treated copper foil. However, as the copper foil with a carrier, a known layer structure can be adopted except that the surface-treated copper foil of the present invention is used.

The carrier is a layer (typically a foil) for supporting the surface-treated copper foil and improving its handleability. Examples of the carrier include an aluminum foil, a copper foil, a resin film having a metal coating on the surface, and the like, and a copper foil is preferable. The copper foil may be either rolled copper foil or electrolytic copper foil. The thickness of the carrier is typically 200 μm or less, preferably 12 μm to 35 μm.

The surface of the carrier on the peeling layer side preferably has a ten-point surface roughness Rzjis of 0.5 to 1.5 μm, and more preferably 0.6 to 1.0 μm. Rzjis can be determined in accordance with JIS B 0601: 2001. By imparting such a ten-point surface roughness Rzjis to the surface of the carrier on the release layer side, a desirable surface profile is imparted to the surface-treated copper foil of the present invention produced via the release layer on the surface. Can be made easier.

The peeling layer is a layer having a function of weakening the peeling strength of the carrier, ensuring the stability of the strength, and further suppressing the mutual diffusion that may occur between the carrier and the copper foil during press molding at a high temperature. .. The release layer is generally formed on one surface of the carrier, but may be formed on both sides. The release layer may be either an organic release layer or an inorganic release layer. Examples of the organic component used in the organic exfoliation layer include nitrogen-containing organic compounds, sulfur-containing organic compounds, and carboxylic acids. Examples of the nitrogen-containing organic compound include a triazole compound and an imidazole compound, and among them, the triazole compound is preferable because the peelability is easily stable. Examples of triazole compounds include 1,2,3-benzotriazole, carboxybenzotriazole, N', N'-bis (benzotriazolylmethyl) urea, 1H-1,2,4-triazole and 3-amino-. Examples thereof include 1H-1,2,4-triazole and the like. Examples of sulfur-containing organic compounds include mercaptobenzothiazole, thiothianulic acid, 2-benzimidazole thiol and the like. Examples of carboxylic acids include monocarboxylic acids and dicarboxylic acids. On the other hand, examples of the inorganic component used in the inorganic release layer include Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, and a chromate-treated film. The release layer may be formed by bringing the release layer component-containing solution into contact with at least one surface of the carrier and fixing the release layer component to the surface of the carrier. The carrier may be brought into contact with the release layer component-containing solution by immersion in the release layer component-containing solution, spraying the release layer component-containing solution, flowing down the release layer component-containing solution, or the like. Further, the release layer component may be fixed to the carrier surface by adsorption or drying of the release layer component-containing solution, electrodeposition of the release layer component in the release layer component-containing solution, or the like. The thickness of the release layer is typically 1 nm to 1 μm, preferably 5 nm to 500 nm.

As the surface-treated copper foil, the surface-treated copper foil of the present invention described above is used. The surface-treated copper foil of the present invention is typically roughened using copper particles, but the procedure is to first form a copper layer as a copper foil on the surface of the release layer, and then at least roughen it. It should be changed. The details of the roughening are as described above. The copper foil is preferably formed in the form of an ultrathin copper foil in order to take advantage of the copper foil with a carrier. The thickness of the ultrathin copper foil is preferably 0.1 μm to 7 μm, more preferably 0.5 μm to 5 μm, and even more preferably 0.5 μm to 3 μm.

Another functional layer may be provided between the release layer and the copper foil. An example of such another functional layer is an auxiliary metal layer. The auxiliary metal layer is preferably made of nickel and / or cobalt. The thickness of the auxiliary metal layer is preferably 0.001 to 3 μm.

Copper-clad laminate The surface-treated copper foil or the copper foil with a carrier of the present invention is preferably used for producing a copper-clad laminate for a printed wiring board. That is, according to a preferred embodiment of the present invention, a method for producing a copper-clad laminate, which comprises producing a copper-clad laminate using the surface-treated copper foil or the carrier-attached copper foil, or the surface treatment. A copper-clad laminate obtained by using a copper foil or the copper foil with a carrier is provided. By using the surface-treated copper foil or the copper foil with a carrier of the present invention, it is possible to provide a copper-clad laminate particularly suitable for the SAP method. This copper-clad laminate comprises the copper foil with a carrier of the present invention and a resin layer provided in close contact with the treated surface. The copper foil with a carrier may be provided on one side of the resin layer or may be provided on both sides. The resin layer contains a resin, preferably an insulating resin. The resin layer is preferably a prepreg and / or a resin sheet. Prepreg is a general term for composite materials in which a base material such as a synthetic resin plate, a glass plate, a glass woven fabric, a glass non-woven fabric, or paper is impregnated with a synthetic resin. Preferred examples of the insulating resin include epoxy resin, cyanate resin, bismaleimide triazine resin (BT resin), polyphenylene ether resin, phenol resin and the like. Further, examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resin, polyimide resin, and polyester resin. Further, the resin layer may contain filler particles made of various inorganic particles such as silica and alumina from the viewpoint of improving the insulating property. The thickness of the resin layer is not particularly limited, but is preferably 1 to 1000 μm, more preferably 2 to 400 μm, and even more preferably 3 to 200 μm. The resin layer may be composed of a plurality of layers. A resin layer such as a prepreg and / or a resin sheet may be provided on the copper foil with a carrier via a primer resin layer previously applied to the surface of the copper foil.

Printed Wiring Board The surface-treated copper foil or copper foil with a carrier of the present invention is preferably used for producing a printed wiring board, and particularly preferably used for producing a printed wiring board by the SAP method. That is, according to a preferred embodiment of the present invention, a method for manufacturing a printed wiring board, which comprises manufacturing a printed wiring board using the above-mentioned surface-treated copper foil or the above-mentioned copper foil with a carrier, or the above-mentioned surface treatment. A printed wiring board obtained by using a copper foil or the copper foil with a carrier is provided. By using the surface-treated copper foil or the copper foil with a carrier of the present invention, in the production of printed wiring boards, a laminated body has a surface profile that is excellent not only in excellent plating circuit adhesion but also in etchability for electroless copper plating. It is possible to provide a surface-treated copper foil that can be applied to. Further, by using the surface-treated copper foil, extremely fine dry film resolution can be realized in the dry film developing step in the SAP method. Therefore, it is possible to provide a printed wiring board in which an extremely fine circuit is formed. The printed wiring board according to this embodiment includes a layer structure in which a resin layer and a copper layer are laminated in this order. In the case of the SAP method, the surface-treated copper foil of the present invention is removed in the step (c) of FIG. 1, so that the printed wiring board produced by the SAP method no longer contains the surface-treated copper foil of the present invention and has a surface surface. Only the surface profile transferred from the treated surface of the treated copper foil remains. The resin layer is as described above for the copper-clad laminate. In any case, a known layer structure can be adopted for the printed wiring board. Specific examples of the printed wiring board include a single-sided or double-sided printed wiring board in which a circuit is formed by adhering the surface-treated copper foil of the present invention to one or both sides of a prepreg to form a cured laminate, or a multilayer in which these are multilayered. Examples include printed wiring boards. Further, as another specific example, a flexible printed wiring board, COF, TAB tape, etc., in which the surface-treated copper foil of the present invention is formed on a resin film to form a circuit can be mentioned. As still another specific example, after forming a copper foil with resin (RCC) in which the above-mentioned resin layer is applied to the surface-treated copper foil of the present invention and laminating the resin layer as an insulating adhesive layer on the above-mentioned printed circuit board. , A build-up wiring board in which a circuit is formed by a method such as the MSAP method or a subtractive method using the surface-treated copper foil as all or a part of the wiring layer, or a build in which a circuit is formed by the SAP method by removing the surface-treated copper foil. Examples thereof include an up wiring board, a direct build-up on wafer in which a copper foil with a resin is laminated and a circuit is formed alternately on a semiconductor integrated circuit. As a more advanced specific example, an antenna element formed by laminating the above-mentioned copper foil with resin on a base material and forming a circuit, an electronic material for a panel display or a window formed by laminating a pattern on glass or a resin film via an adhesive layer. Examples thereof include electronic materials for glass, electromagnetic wave shield films obtained by applying a conductive adhesive to the surface-treated copper foil of the present invention, and the like. In particular, the copper foil with a carrier of the present invention is suitable for the SAP method. For example, when the circuit is formed by the SAP method, the configuration shown in FIGS. 1 and 2 can be adopted.

The present invention will be described in more detail with reference to the following examples.

Examples 1 and 2
As the surface-treated copper foil with a carrier, a roughened copper foil with a carrier was prepared and evaluated as follows.

(1) Preparation of carrier Using a copper sulfate solution having the composition shown below as the copper electrolytic solution, a rotating electrode made of titanium having an arithmetic average surface roughness Ra (based on JIS B 0601: 2001) of 0.20 μm was attached to the cathode. A DSA (dimensionally stable anode) was used as the anode, and electrolysis was performed at a solution temperature of 45 ° C. and a current density of 55 A / dm ² , to obtain an electrolytic copper foil having a thickness of 12 μm as a carrier. The ten-point average roughness Rzjis of the surface of the obtained carrier on the peeling layer side was measured according to JIS B 0601: 2001 and found to be 0.9 μm.
<Composition of copper sulfate solution>
-Copper concentration: 80 g / L
-Sulfuric acid concentration: 260 g / L
-Bis (3-sulfopropyl) disulfide concentration: 30 mg / L
-Diallyldimethylammonium chloride polymer concentration: 50 mg / L
-Chlorine concentration: 40 mg / L

(2) Formation of release layer The electrode surface side of the pickled carrier copper foil is put into a CBTA aqueous solution having a CBTA (carboxybenzotriazole) concentration of 1 g / L, a sulfuric acid concentration of 150 g / L, and a copper concentration of 10 g / L. The CBTA component was adsorbed on the electrode surface of the carrier by immersing at a temperature of 30 ° C. for 30 seconds. In this way, the CBTA layer was formed as an organic release layer on the surface of the electrode surface of the copper foil for the carrier.

(3) Formation of Auxiliary Metal Layer The carrier copper foil on which the organic release layer was formed was immersed in a solution having a nickel concentration of 20 g / L prepared using nickel sulfate, and the liquid temperature was 45 ° C., pH 3, and current density. Under the condition of 5 A / dm ² , an adhered amount of nickel corresponding to a thickness of 0.001 μm was adhered onto the organic release layer. In this way, a nickel layer was formed as an auxiliary metal layer on the organic release layer.

(4) Formation of ultra-thin copper foil A copper foil for a carrier on which an auxiliary metal layer is formed is immersed in a copper sulfate solution having the composition shown below, and electrolyzed at ^{a solution temperature of 50 ° C. and a current density of 5 to 30 A / dm 2.} An ultrathin copper foil having a thickness of 3 μm (Examples 1, 3 and 4) or 2.5 μm (Example 2) was formed on the auxiliary metal layer.
<Solution composition>
-Copper concentration: 60 g / L
-Sulfuric acid concentration: 200 g / L

(5) Roughing treatment A roughening treatment was performed on the deposited surface of the above-mentioned ultrathin copper foil. This roughening treatment was performed by the following two-step plating. The first-step plating step is performed twice in total using two tanks, and each plating step (that is, each tank) uses a copper sulfate solution containing a copper concentration of 10.8 g / L and a sulfuric acid concentration of 230 to 250 g / L. Then, electrodeposition was performed under plating conditions of a solution temperature of 25 ° C. and a current density of 25 A / dm ^2. In the second-stage plating step, electrodeposition was performed using a copper sulfate solution containing a copper concentration of 70 g / L and a sulfuric acid concentration of 230 to 250 g / L ^{under plating conditions of a solution temperature of 50 ° C. and a current density of 58 A / dm 2.} .. As for the amount of electricity in each stage, the ratio (Q ₁ / Q _{2 ) of the amount of electricity Q 1 in} the first plating process to the amount of electricity Q ₂ in the second plating process is less than 1 (specifically 0.87). ). Specifically, electrodeposition was performed under the conditions shown in Table 1.

(6) Rust prevention treatment Both sides of the copper foil with a carrier after the roughening treatment were subjected to a rust prevention treatment consisting of an inorganic rust prevention treatment and a chromate treatment. First, as an inorganic rust preventive treatment, a pyrophosphate bath was used at a potassium pyrophosphate concentration of 80 g / L, a zinc concentration of 0.2 g / L, a nickel concentration of 2 g / L, a liquid temperature of 40 ° C., and a current density of 0.5 A / dm ² . Zinc-nickel alloy rust prevention treatment was performed. Next, as a chromate treatment, a chromate layer was further formed on the zinc-nickel alloy rust preventive treatment. This chromate treatment was carried out at a chromic acid concentration of 1 g / L, a pH of 11, a solution temperature of 25 ° C., and a current density of 1 A / dm ² .

(7) Silane Coupling Agent Treatment The copper foil that has been subjected to the above rust preventive treatment is washed with water, and then immediately treated with the silane coupling agent to adsorb the silane coupling agent on the rust preventive treatment layer on the roughened surface. rice field. In this silane coupling agent treatment, pure water is used as a solvent, a solution having a 3-aminopropyltrimethoxysilane concentration of 3 g / L is used, and this solution is sprayed on the roughened surface by showering to adsorb. went. After the adsorption of the silane coupling agent, the moisture is finally dissipated by an electric heater, and the carrier is provided with a roughened copper foil having a thickness of 3 μm (Examples 1, 3 and 4) or 2.5 μm (Example 2). Obtained copper foil.

(8) Evaluation of Roughened Copper Foil The obtained roughened copper foil was subjected to various characteristics of the surface profile containing roughened particles as follows.

<Spc and Spd of roughened copper foil>
^{The surface profile of a two-dimensional region (10 μm × 10 μm) having an area of 100 μm 2 on} the roughened surface of the roughened copper foil was analyzed by a laser method using a laser microscope (Keence Co., Ltd., VK-X100) and roughened. ^{The arithmetic mean curve Spc (mm -1} ) and the peak density Spd (mm ^-2 ) of the peaks on the roughened surface of the chemical-treated copper foil were measured according to ISO25178. This measurement was performed with the cutoff wavelength of the S filter set to 0.8 μm and the cutoff wavelength of the L filter set to 0.1 μm. The above measurement was performed a total of 3 times for the same sample, and the average value thereof was adopted as the measured value.

<Spc and Smr1 on the surface of the resin replica>
A replica shape of the surface profile of the roughened surface of the roughened copper foil was prepared with a resin, and the surface profile of the obtained resin replica surface was analyzed. Specifically, first, a copper foil with a carrier was laminated on a prepreg (manufactured by Mitsubishi Gas Chemical Company, Limited, GHPL-830NS, thickness 0.1 mm) so that the ultrathin copper foil side was in contact with the prepreg, and the pressure was 4.0 MPa. , Thermocompression bonded at a temperature of 220 ° C. for 90 minutes. Then, the carrier was peeled off, and the crimped ultrathin copper foil was completely removed with a copper chloride-based etching solution to obtain a resin replica to which the surface profile of the roughened surface was transferred. A laser microscope (manufactured by Keyence Co., Ltd., VK-X100) was used to obtain a surface profile of a two-dimensional region (10 μm × 10 ^{μm) having an area of 100 μm 2 on} the transfer surface (the surface to which the surface profile of the roughened surface was transferred) of this resin replica. ^{The arithmetic average curve Spc (mm -1} ) of the peak of the peak on the resin replica surface and the load area ratio Smr1 (%) that separates the protruding peak and the core were measured according to ISO25178. .. This measurement was performed with the cutoff wavelength of the S filter set to 0.8 μm and the cutoff wavelength of the L filter set to 0.1 μm. The above measurement was performed a total of 3 times for the same sample, and the average value thereof was adopted as the measured value.

(9) Preparation of Copper-clad Laminated Plate A copper-clad laminate was prepared using a copper foil with a carrier. First, an ultrathin copper foil with a carrier is laminated on the surface of the inner layer substrate via a prepreg (GHPL-830NSF, thickness 0.1 mm), pressure 4.0 MPa, temperature 220. After thermocompression bonding at ° C. for 90 minutes, the carrier was peeled off to prepare a copper-clad laminate.

(10) Preparation of SAP Evaluation Laminated Body Next, after removing all the copper foil on the surface with a sulfuric acid / hydrogen peroxide-based etching solution, degreasing, Pd-based catalyst addition, and activation treatment were performed. Electroless copper plating (thickness: 1 μm) was performed on the surface activated in this way to obtain a laminate immediately before the dry film was laminated by the SAP method (hereinafter referred to as SAP evaluation laminate). These steps were performed according to the known conditions of the SAP method.

(11) Evaluation of SAP Evaluation Laminate The various characteristics of the obtained SAP evaluation laminate were evaluated as follows.

<Plating circuit adhesion (peeling strength)>
A dry film was attached to the laminate for SAP evaluation, and exposure and development were performed. A copper layer having a thickness of 19 μm was deposited on the laminate masked with the developed dry film by pattern plating, and then the dry film was peeled off. The electroless copper plating exposed with a sulfuric acid / hydrogen peroxide-based etching solution was removed, and a sample for measuring peel strength having a height of 20 μm and a width of 10 mm was prepared. The peel strength at the time of peeling the copper foil from the evaluation sample was measured according to JIS C 6481 (1996).

<Etching property>
The SAP evaluation laminate was etched with a sulfuric acid / hydrogen peroxide-based etching solution by 0.2 μm each, and the amount (depth) until the copper on the surface was completely eliminated was measured. The measuring method was confirmed with an optical microscope (500 times). More specifically, the work of confirming the presence or absence of copper with an optical microscope was repeated every time 0.2 μm was etched, and the value (μm) obtained by (number of etchings) × 0.2 μm was used as an index of etchability. For example, an etching property of 1.2 μm means that after etching 0.2 μm 6 times, residual copper is no longer detected by the optical microscope (that is, 0.2 μm × 6 times = 1.2 μm). ). That is, the smaller this value is, the smaller the number of times of etching is required to remove the copper on the surface. That is, the smaller this value is, the better the etching property is.

<Dry film resolution (minimum L / S)>
A dry film having a thickness of 25 μm was attached to the surface of the SAP evaluation laminate, and exposure and development were performed using a mask having a line / space (L / S) pattern of 2 μm / 2 μm to 15 μm / 15 μm. .. The exposure amount at this time was 125 mJ. The surface of the developed sample was observed with an optical microscope (500 times), and the smallest (that is, the finest) L / S in the L / S that could be developed without any problem was adopted as an index of dry film resolution. For example, the minimum L / S = 10 μm / 10 μm, which is an index for evaluating the resolution of dry film, means that the resolution from L / S = 15 μm / 15 μm to 10 μm / 10 μm could be achieved without any problem. For example, when the resolution is successful, a clear contrast is observed between the dry film patterns, whereas when the resolution is not good, a darkened portion is observed between the dry film patterns and is clear. No contrast is observed.

Example 3 (comparison)
The ratio (Q ₁ / Q _{2 ) of the amount of electricity Q 1 in} the first-stage plating process to the amount of electricity Q ₂ in the second-stage plating process in the roughening process was set to 2.16 (specifically). The roughened copper foil with a carrier was prepared and evaluated in the same manner as in the procedure described for Example 1 except that electrodeposition was performed under the conditions shown in Table 1.

Example 4 (comparison)
The ratio (Q ₁ / Q _{2 ) of the amount of electricity Q 1 in} the first-stage plating process to the amount of electricity Q ₂ in the second-stage plating process in the roughening process was set to 3.38 (specifically). The roughened copper foil with a carrier was prepared and evaluated in the same manner as in the procedure described for Example 1 except that electrodeposition was performed under the conditions shown in Table 1.

Results The evaluation results obtained in Examples 1 to 4 are as shown in Table 2.

Claims (10)

A surface-treated copper foil having a treated surface on at least one side.
The treated surface has an arithmetic mean music Spc of the peak peak measured in accordance with ISO25178 of 60 mm ^-1 or more and 200 mm ^-1 or less .
When a resin film is thermocompression bonded to the treated surface to transfer the surface shape of the treated surface to the surface of the resin film and the surface-treated copper foil is removed by etching, the surface of the resin film remains. , A surface-treated copper foil having a peak arithmetic average Spc of 55 mm ^{-1 or more, which is measured in accordance with ISO25178.} The surface of the resin film left after the etching has a load area ratio Smr1 for separating the protruding peak portion and the core portion, which is measured in accordance with ISO25178, of 9.0% or more, according to claim 1. The surface-treated copper foil described. The surface-treated copper foil according to claim 1 or 2, wherein roughened particles are adhered to the treated surface. The surface-treated copper foil according to any one of claims 1 to 3, wherein the treated surface has a peak density Spd of 5000 mm- ² or more and 20000 mm- ^{2 or less measured in accordance with ISO25178.} The surface-treated copper foil according to any one of claims 1 to 4, wherein the surface-treated copper foil has a thickness of 0.5 to 5 μm. The surface-treated copper foil according to any one of claims 1 to 5, which is used for transferring an uneven shape to an insulating resin layer for a printed wiring board. The surface-treated copper foil according to any one of claims 1 to 6, which is used for producing a printed wiring board by a semi-additive method. The carrier, the peeling layer provided on the carrier, and the surface-treated copper foil according to any one of claims 1 to 7 provided on the peeling layer with the treated surface facing outward. , Copper foil with carrier. Manufacture of a copper-clad laminate, characterized in that a copper-clad laminate is produced using the surface-treated copper foil according to any one of claims 1 to 7 or the carrier-attached copper foil according to claim 8. Method. A method for manufacturing a printed wiring board, which comprises manufacturing a printed wiring board using the surface-treated copper foil according to any one of claims 1 to 7 or the copper foil with a carrier according to claim 8.

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