TWI745668B - Roughened copper foil, copper foil with carrier, copper clad laminate and printed wiring board - Google Patents

Abstract

The present invention provides a roughened copper foil, which is a low-thickness roughened copper foil suitable for the formation of thin-line circuits. When used in the SAP method, it can not only impart etching properties for electroless copper plating to a laminate and Dry film resolution and circuit adhesion based on shear strength are also excellent in surface profile. The roughened copper foil is a roughened copper foil with a roughened surface on at least one side. The roughened surface is provided with a plurality of roughened particles. The roughened copper foil has a length of 10μm in the cross section of the roughened particles. The ratio of the square of L (μm) to the area S (μm ² ) of the ^{roughened particles. The average value of L 2} /S is 16 or more and 30 or less, and the ten-point average roughness Rz of the roughened surface is 0.7 μm or more and 1.7 Below μm.

Description

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

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

In recent years, the most suitable method of manufacturing printed wiring boards for the miniaturization of circuits has been widely adopted by the SAP (Semiadditive process: semi-additive process) method. The SAP method is a method suitable for forming extremely fine circuits. As an example, it is performed using a copper foil with a carrier for roughening treatment. For example, as shown in Figures 1 and 2, the roughened copper foil 110 is crimped and adhered to the insulating resin substrate 111 provided with the lower circuit 111b on the base substrate 111a using the prepreg 112 and the primer layer 113 (step (a)) After the carrier (not shown) is peeled off from the roughened copper foil 110, a through hole (114) is formed by laser perforation as needed (step (b)). Next, the roughened copper foil 110 is removed by etching, so that the undercoat layer 113 with the roughened surface profile is exposed (step (c)). After performing electroless copper plating 115 on the roughened surface (step (d)), by using the dry film 116 for exposure and development, masking with a specific pattern (step (e)), copper electroplating 117 (step ( f)). After the dry film 116 is removed to form the wiring portion 117a (step (g)), the unnecessary electroless copper plating 115 between the adjacent wiring portions 117a and 117a is removed by etching (step (h)) to obtain a specific pattern The wiring 118 formed.

In this way, the SAP method of roughening copper foil is used, and the roughening copper foil itself is removed by etching after laser perforation (step (c)). Moreover, since the roughened copper foil has been removed from the laminate surface, the roughened copper foil has a roughened surface of the roughened surface. The roughened surface of the roughened copper foil can ensure an insulating layer (such as primer 113 or no primer) in the subsequent steps. The layer 113 is the adhesion between the prepreg 112) and the plated circuit (for example, the wiring 118). However, the surface profile suitable for improving the adhesion with the plated circuit tends to become rough roughness, so in step (h), the etching property for electroless copper plating tends to decrease. That is to say, in the part of the electroless copper plating that bites into the rough unevenness, more etching is required in order to prevent the copper from remaining.

Therefore, it is proposed to reduce the roughened particles and have a necked shape. When used in the SAP method, it is possible to achieve good etching properties while ensuring the necessary adhesion of the plating circuit. For example, Patent Document 1 (International Publication No. 2016/158775) discloses a roughened copper foil having a roughened surface on at least one side. The roughened surface is provided with a plurality of spherical protrusions made of copper particles. The average height of the spherical protrusions is 2.60 μm or less. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2016/158775

In recent years, with the further miniaturization of circuits required by SAP, the adhesion strength (absolute value) between the circuit and the substrate has decreased. However, as shown in FIGS. 3A and 3B, the circuit 124 formed on the substrate 112 may be covered by the solder resist 126 on its longitudinal side (FIG. 3A) and uncovered (FIG. 3B). When the circuit 124 is covered by the solder resist 126, since the circuit 124 is protected by the solder resist 126, the risk of the circuit 124 peeling off the substrate 122 during the operation step is relatively small, that is, the risk of impairing the adhesion between the circuit 124 and the substrate 122 is relatively small. small. On the other hand, when the circuit 124 is not covered with the solder resist 126, since the circuit 124 is not protected by the solder resist 126, when the adhesion strength between the circuit 124 and the substrate 122 is reduced due to the miniaturization of the circuit 124, the circuit 124 will peel off during the operation step. The risk becomes greater. In this regard, one of the physical adhesion indicators between the circuit and the substrate is the shear strength. In order to prevent the circuit from peeling off during the operation step, the current situation is that the miniaturization of the circuit can only be carried out to ensure a certain level of shear strength or more. Line width. Therefore, in order to miniaturize the circuit 124 that is not covered by the solder resist 126, in addition to etching properties and dry film resolution, it is also desirable to ensure sufficient shear strength even with a thin line width. However, even if good peel strength can be ensured by the method disclosed in Patent Document 1, it is difficult to ensure sufficient shear strength corresponding to wire thinning.

The findings obtained by the present inventors today are that by controlling the shape of the roughened particles, it can be a low-thickness roughening copper foil suitable for the formation of fine-line circuits with a ten-point average roughness Rz of 1.7 μm or less, and It can achieve excellent circuit adhesion based on the viewpoint of shear strength. That is, the knowledge obtained is that a low-thickness roughening copper foil suitable for the formation of thin-line circuits, and when used in the SAP method, not only can provide the layered body with etching properties for electroless copper plating, but also based on shearing. The surface profile of the circuit adhesion is also excellent from the viewpoint of strength. The knowledge also obtained is that by using the above-mentioned roughening treatment copper foil, in the dry film development step of the SAP method, extremely fine dry film resolution can be achieved.

Therefore, the object of the present invention is to provide a roughened copper foil, which is a low-thickness roughened copper foil suitable for the formation of thin-line circuits, and when used in the SAP method, it can not only impart an electroless copper plating to the laminate The etching performance and dry film resolution of the coating, and the surface profile of the circuit adhesion based on the viewpoint of the shear strength are also excellent. And another object of this invention is to provide the copper foil with a carrier provided with such a roughening process copper foil.

According to one aspect of the present invention, there is provided a roughened copper foil, which is a roughened copper foil having a roughened surface on at least one side, the roughened surface is provided with a plurality of roughened particles, and the roughened copper The average value of the ratio L ² /S of the square of the peripheral length L (μm) of the roughened particles to the area S (μm ² ) of the roughened particles in the cross section of the foil with a length of 10 μm is 16 or more and 30 or less, and The ten-point average roughness Rz of the roughened surface is 0.7 μm or more and 1.7 μm or less.

According to another aspect of the present invention, there is provided a copper foil with a carrier, which includes a carrier, a peeling layer provided on the carrier, and the roughening treatment provided on the peeling layer with the roughening treatment surface as the outer side Copper foil.

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

According to another aspect of the present invention, a printed wiring board is provided, which is obtained by using the aforementioned roughened copper foil or the aforementioned copper foil with a carrier. Or, according to another aspect of the present invention, there is provided a method of manufacturing a printed wiring board, which is characterized by using the aforementioned roughened copper foil or the aforementioned copper foil with a carrier to manufacture a printed wiring board.

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

In this specification, the so-called "roughened particles" are as shown schematically in FIG. 4. The particles 12 with a height exceeding 150 nm formed directly on the surface of the base surface 10a of the roughened copper foil 10 include slightly spherical and needle-shaped particles. All shapes such as, columnar, elongated shapes, etc., but preferably have a "slightly spherical protrusion" form. In this specification, the term "substantially spherical projections" refers to projections that have a roughly spherical rounded outline shape and can be distinguished from irregularly shaped projections or particles such as needle-like, columnar, and elongated shapes. As shown as the roughened particles 12 in Fig. 4, the substantially spherical protrusions are connected to the base surface 10a of the copper foil at the constricted base portion connected to the base surface 10a of the copper foil, and therefore cannot become a perfect sphere, but as long as the base portion is outside The part should be roughly spherical. Therefore, as long as the roughly spherical protrusions can maintain the roughly spherical rounded shape, fine irregularities, deformations, etc. are also allowed. In addition, the above-mentioned protrusion may also be simply referred to as a spherical protrusion, and since it cannot be a perfect spherical body as described above, it should be understood to mean the above-mentioned substantially spherical protrusion. In addition, the protrusions 12a formed on the surface of the roughened particles 12 that are not directly formed on the base surface 10a of the roughened copper foil 10 may constitute a part of the roughened particles 12.

The present specification, the term "coarse particles around the length L", as shown schematically in FIG. 5, based coarse particles 12 of the cross-sectional contour line 12p (the solid line portion of FIG. 5) and the length L _p and rough contour line 12p The total length _{L s (L p} + L _s ) of the line segment 12 s (the dotted line part of FIG. 5) connected between _{the contact points c 1} and c ₂ of the base surface 10 a of the copper foil 10 is chemically treated. In addition, the so-called "area S of the roughened particle" is schematically shown in FIG. The peripheral length L and the area S of the roughened particles 12 can be identified by analyzing the cross-sectional image of the roughened copper foil 10 obtained by SEM observation using commercially available software. For example, image analysis software Image-Pro Plus 5.1J (manufactured by Media Cybernetics, Inc.) can be used to perform image analysis according to the conditions described in the embodiments of this specification.

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

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

Roughened Copper Foil The copper foil of the present invention is a roughened copper foil. The roughened copper foil has a roughened surface on at least one side. The roughening treatment surface is schematically shown in FIG. 4, and includes a plurality of roughening particles 12. Roughened copper foil 10 a cross-sectional length of the coarse particles of 10μm around the length 12 L (μm) of the square of the coarse particles with respect to the area S (μm ²⁾ the ratio L ² / S is not less than the average value of 12 16 Below 30. In addition, the ten-point average roughness Rz of the roughened surface is 0.7 μm or more and 1.7 μm or less. By controlling the shape of the roughened particles in this way, it can be a low-thickness roughening copper foil suitable for the formation of fine-line circuits with a ten-point average roughness Rz of 1.7 μm or less, and the viewpoint based on the shear strength can be realized. Excellent circuit adhesion. That is, it can be a low-thickness roughened copper foil suitable for the formation of thin-line circuits. When used in the SAP method, it can not only impart etching properties to electroless copper plating to the laminate, but also based on the shear strength The surface profile of the viewpoint that the circuit adhesion is also excellent. In addition, by using the above-mentioned roughening treatment copper foil, in the dry film development step in the SAP method, extremely fine dry film resolution can be achieved.

It is inherently difficult to have both the adhesion of the plated circuit and the etching properties for electroless copper plating. That is, as mentioned above, the surface profile suitable for improving the adhesion to the plated circuit tends to become rougher roughness. Therefore, in the step (h) of FIG. 2, the etching property of electroless copper plating tends to decrease. . That is, in the part where the roughness is bitten in the electroless copper plating, more etching is required in order to prevent the copper from remaining. In this regard, according to the roughening treatment copper foil of Patent Document 1, the amount of etching can be reduced, and excellent plating circuit adhesion can be ensured. However, in recent years, with the further miniaturization of circuits required by the SAP method, the adhesion strength (absolute value) between the circuit and the substrate has decreased. As a result, the method disclosed in Patent Document 1 can ensure good peel strength, but it is also difficult. Ensure sufficient shear strength corresponding to thinning. Therefore, when the circuit is not covered with solder resist, the risk of circuit peeling during the operation steps increases. In contrast, in the present invention, by controlling the shape of the roughened particles 12, the roughened particles can be greatly reduced in diameter to a level suitable for the formation of thin-line circuits with a ten-point average roughness Rz of 1.7 μm or less. Greatly improve the circuit adhesion based on the viewpoint of shear strength. That is, by reducing the diameter of the roughened particles 12 represented by Rz in the above range, the circuit adhesion would be reduced originally, but in the present invention, the parameter representing the cross-sectional shape of the roughened particles 12 When the average value of the ratio L ² /S is set to 16 or more and 30 or less, it is possible to realize excellent circuit adhesion based on the viewpoint of shear strength. Moreover, since these excellent adhesion properties and excellent etching properties for electroless copper plating can be combined, it is believed that in the dry film development step of the SAP method, extremely fine dry film resolution can be achieved. Therefore, the roughened copper foil 10 of the present invention can be better used in the production of printed wiring boards using the semi-additive method (SAP). If it has other performances, it can be said that the roughened copper foil 10 of the present invention is preferably used to transfer the concave-convex shape to the insulating resin layer for a printed wiring board.

The roughened copper foil 10 of the present invention has a roughened surface on at least one side. That is, the roughened copper foil may have a roughened surface on both sides, or may have a roughened surface on only one side. When there are roughened surfaces on both sides, when used in the SAP method, the surface on the side where the laser is irradiated (the surface away from the insulating resin surface) is also roughened, so the laser absorption is improved. As a result, the laser perforation can also be improved.

The roughening treatment surface is provided with a plurality of roughening particles 12, and each of the plurality of roughening particles 12 is preferably made of copper particles. The copper particles may be made of metallic copper, or may be made of copper alloy. However, when the copper particles are copper alloys, the solubility of the copper etching solution may be reduced, or alloy components may be mixed in the copper etching solution to reduce the life of the etching solution. Therefore, the copper particles are preferably made of metallic copper.

Roughened copper foil 10 of the cross-sectional length of 10μm around the coarse particles 12 of length L (μm) of the square of the coarse particles with respect to the area S (μm ²⁾ the ratio L ² / S is not less than the average value of 12 16 30 or less, preferably 19 or more and 27 or less, more preferably 19 or more and 26 or less, still more preferably 19 or more and 25 or less, particularly preferably 20 or more and 24 or less. If it is within these ranges, the roughened particles 12 can be effectively prevented from falling off, and the shear strength can be further improved.

The ten-point average roughness Rz of the roughened surface is 0.7 μm or more and 1.7 μm or less, preferably 0.7 μm or more and 1.6 μm or less, more preferably 0.8 μm or more and 1.5 μm or less. If it is within these ranges, the desired shear strength can be ensured, and the fine line forming properties can be further improved. Rz is determined in accordance with JIS B 0601-1994.

The number of roughened particles 12 in the cross section of the roughened copper foil 10 having a length of 10 μm is preferably 20 or more and 70 or less, more preferably 20 or more and 60 or less, and still more preferably 20 or more and 40 or less. If it is within these ranges, the roughened particles 12 can be effectively prevented from falling off, and the shear strength can be further improved.

The thickness of the roughened copper foil 10 of the present invention is not particularly limited, but is preferably 0.1 μm or more and 18 μm or less, more preferably 0.5 μm or more and 7 μm or less, still more preferably 0.5 μm or more and 5 μm or less, particularly preferably 0.5 μm or more Below 3μm. The thickness includes the thickness of the roughened particles 12. Moreover, the roughening process copper foil 10 of this invention is not limited to the thing which roughened the surface of the normal copper foil, and may be the thing which roughened the copper foil surface of the copper foil with a carrier.

Manufacturing method of roughened copper foil Although an example of a preferable manufacturing method of the roughened copper foil of the present invention is described, the roughened copper foil of the present invention is not limited to the method described below, as long as the surface profile of the roughened copper foil of the present invention can be realized. Can be made by all methods.

(1) Preparation of copper foil As the copper foil used in the manufacture of the roughened copper foil, both electrolytic copper foil and rolled copper foil can be used. The thickness of the copper foil is not particularly limited, but is preferably 0.1 μm or more and 18 μm or less, more preferably 0.5 μm or more and 7 μm or less, still more preferably 0.5 μm or more and 5 μm or less, particularly preferably 0.5 μm or more and 3 μm or less. When the copper foil is prepared in the form of a copper foil with a carrier, the copper foil can be a wet film forming method such as electroless copper plating and electrolytic copper plating, and a dry film forming method such as sputtering and chemical vapor deposition. Or a combination of these.

(2) The roughening treatment uses copper particles to roughen at least one surface of the copper foil. The roughening is performed by electrolysis using a copper electrolytic solution for roughening treatment. This electrolysis is preferably carried out through a three-stage plating step. In the plating step of the first stage, it is preferable to use a copper concentration of 5 g/L or more and 20 g/L or less, a sulfuric acid concentration of 30 g/L or more and 200 g/L or less, a chlorine concentration of 20 ppm or more and 100 ppm or less, and 9-phenyl acridine ( 9PA) A copper sulfate solution with a concentration of 20 ppm or more and 100 ppm or less is electroplated under the plating conditions of a liquid temperature of 20°C or more and 40°C, a current density of 5 A/dm ² or more and 25 A/dm ² or less, and a time of 2 seconds or more and 10 seconds or less. In the second plating step, it is better to use a copper sulfate solution containing a copper concentration of 65g/L or more and 80g/L or less and a sulfuric acid concentration of 200g/L or more and 280g/L or less, at a liquid temperature of 45℃ or more and 55℃ or less and current Electroplating is performed on plating conditions with a density of 1 A/dm ² or more and 10 A/dm ² or less, and a time of 2 seconds or more and 25 seconds or less. In the plating step of the third stage, it is preferable to use a copper concentration of 10 g/L or more and 20 g/L or less, a sulfuric acid concentration of 30 g/L or more and 130 g/L or less, a chlorine concentration of 20 ppm or more and 100 ppm or less, and a 9PA concentration of 100 ppm or more and 200 ppm or less. The copper sulfate solution is electroplated under the plating conditions of a liquid temperature of 20°C or more and 40°C or less, a current density of 10 A/dm ² or more and 40 A/dm ² or less, and a time of 0.3 seconds or more and 1.0 seconds or less. By performing the third-stage plating process using additives such as 9PA, the surface of the roughened particles formed in the first-stage and second-stage plating processes forms minute protrusions, and the ratio L ² /S can be increased. It is particularly preferable to use additives such as 9PA in the first stage of the plating step. The total amount of electricity Q ₁ in the first stage of plating step and the amount of electricity Q _{2 in} the second stage of plating step (Q ₁ + Q ₂ ) It is preferably set to 100 C/dm ² or less. In addition, the linear flow velocity of the plating solution to the copper foil in the plating steps of the first to third stages is preferably 0.10 m/s or more and 0.50 m/s or less, more preferably 0.15 m/s or more and 0.45 m/s or less. In this way, a relatively low roughness surface profile that satisfies the ten-point average roughness Rz≦1.7μm can be formed, and the third-stage plating can cover the entire surface of the roughened particles to form roughened particles larger ^{than L 2 /S} .

(3) Anti-rust treatment Anti-rust treatment has no effect on the shape, surrounding length and area of the roughened particles, and the ten-point average roughness Rz inside the roughened part. Therefore, the roughened copper foil can be subjected to anti-rust treatment according to expectations. The anti-rust treatment preferably includes a plating treatment using zinc. The plating treatment using zinc may be either zinc plating treatment or zinc alloy plating treatment, and 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, and Co. The Ni/Zn adhesion ratio in zinc-nickel alloy plating is preferably 1.2 or more and 10 or less in mass ratio, more preferably 2 or more and 7 or less, and still more preferably 2.7 or more and 4 or less. In addition, the rust prevention treatment preferably further includes chromate treatment. This chromate treatment is preferably performed on the plating surface containing zinc after the plating treatment using zinc. If so, the rust resistance can be further improved. The best anti-rust treatment is a combination of zinc-nickel alloy plating treatment and subsequent chromate treatment.

(4) Silane coupling agent treatment According to expectations, the copper foil can also be treated with a silane coupling agent to form a silane coupling agent layer. This can improve moisture resistance, chemical resistance, and adhesion to adhesives. The silane coupling agent layer can be formed by appropriately diluting the silane coupling agent, coating, and drying. Examples of silane coupling agents include epoxy functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, or 3-aminopropyltrimethoxysilane. Ethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy)propyl-3- Amino-functional silane coupling agent such as aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, or mercapto-functional silane such as 3-mercaptopropyltrimethoxysilane Coupling agent, or olefin functional silane coupling agent such as vinyl trimethoxy silane, vinyl phenyl trimethoxy silane, or acrylic functional silane coupling agent such as 3-methacryloxypropyl trimethoxy silane Mixture, or imidazole functional silane coupling agent such as imidazole silane, or triazine functional silane coupling agent such as triazine silane, etc.

Copper foil with carrier The roughened 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 equipped with the carrier, the peeling layer provided on this carrier, and the roughening process copper foil of this invention provided on this peeling layer so that a roughening process surface may be an outer side. However, the copper foil with a carrier can adopt a conventional layer structure other than the roughening process copper foil of this invention.

The carrier system supports the roughening process of the copper foil and is used to improve its handleability (typically a foil). Examples of the carrier include aluminum foil, copper foil, a resin film coated with a metal such as copper or a glass plate on the surface, and copper foil is preferred. The copper foil may be any of rolled copper foil and electrolytic copper foil. The thickness of the carrier is typically 200 μm or less, preferably 12 μm or more and 35 μm or less.

The surface on the side of the release layer with the carrier preferably has a ten-point average roughness Rz of 0.5 μm or more and 1.5 μm or less, more preferably 0.6 μm or more and 1.0 μm or less. Rz can be determined in accordance with JIS B 0601-1994. By imparting such a ten-point surface roughness Rz to the surface on the release layer side of the carrier, it is easy to impart a desired surface profile to the roughening treatment copper foil of the present invention produced through the release layer thereon.

The peeling layer has the function of weakening the peeling strength of the carrier, ensuring the strength stability, and inhibiting the mutual diffusion between the carrier and the copper foil during high-temperature press molding. The release layer is generally formed on one side of the carrier, but can also be formed on both sides. The peeling layer may be any one of an organic peeling layer and an inorganic peeling layer. Examples of organic components used in the organic release layer include nitrogen-containing organic compounds, sulfur-containing organic compounds, carboxylic acids, and the like. As examples of nitrogen-containing organic compounds, triazole compounds, imidazole compounds, etc. are exemplified. Among them, triazole compounds are preferred in terms of easy and stable releasability. Examples of triazole compounds are 1,2,3-benzotriazole, carboxybenzotriazole, N',N'-bis(benzotriazolylmethyl)urea, 1H-1,2,4 -Triazole and 3-amino-1H-1,2,4-triazole, etc. Examples of sulfur-containing organic compounds include mercaptobenzothiazole, thiocyanuric acid, 2-benzimidazole thiol, and the like. As an example of a carboxylic acid, monocarboxylic acid, dicarboxylic acid, etc. are mentioned. On the other hand, as examples of the inorganic components used in the inorganic release layer, Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, chromate treatment films, and the like are exemplified. In addition, the formation of the release layer may be performed by contacting at least one surface of the carrier with a solution containing the release layer component to fix the release layer component on the surface of the carrier. The contact between the carrier and the solution containing the peeling layer component may be performed by immersing the solution containing the peeling layer component, spraying the solution containing the peeling layer component, or flowing down the solution containing the peeling layer component. In addition, the fixing of the release layer component on the surface of the carrier may be performed by adsorption or drying of the solution containing the release layer component, electroplating of the release layer component in the solution containing the release layer component, or the like. The thickness of the peeling layer is typically 1 nm or more and 1 μm or less, preferably 5 nm or more and 500 nm or less.

As the roughened copper foil, the roughened copper foil of the present invention described above is used. The roughening treatment of the present invention implements roughening using copper particles, but as the procedure, first, a copper layer is formed on the surface of the peeling layer as a copper foil, and then at least the roughening is performed. The details of the roughening are as described above. In addition, copper foil is preferably constructed in the form of ultra-thin copper foil by utilizing the advantages of copper foil with a carrier. The preferable thickness of the ultra-thin copper foil is 0.1 μm or more and 7 μm or less, preferably 0.5 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

Other functional layers can also be arranged between the peeling layer and the carrier and/or the copper foil. An example of these other functional layers is an auxiliary metal layer. The auxiliary metal layer is preferably made of nickel and/or cobalt. By forming this auxiliary metal layer due to the peeling layer side of the carrier and/or the peeling layer side of the roughened copper foil, it is possible to further suppress the interaction between the carrier and the roughened copper foil during high temperature or long-term hot press molding. Diffusion can guarantee the stability of the peel strength of the carrier. The thickness of the auxiliary metal layer is preferably from 0.001 μm to 3 μm.

Copper Clad Laminate The roughened copper foil or copper foil with a carrier of the present invention is preferably used in the production of copper-clad laminates for printed wiring boards. That is, according to a preferable aspect of the present invention, a copper-clad laminated board provided with the above-mentioned roughened copper foil or the above-mentioned copper foil with a carrier is provided. By using the roughened copper foil or copper foil with a carrier of the present invention, it is possible to provide a copper-clad laminate that is particularly suitable for the SAP method. The copper-clad laminated board is made up of the roughened copper foil of the present invention and a resin layer that is provided in close contact with the roughened surface of the roughened copper foil, or it has the copper foil with a carrier of the present invention and adhered to The roughening treatment of the copper foil with a carrier is formed by a resin layer provided on the roughening treatment surface of the copper foil. The roughened copper foil or copper foil with a carrier can be provided on one side of the resin layer or on both sides. The resin layer contains resin, and preferably contains insulating resin. The resin layer is preferably a prepreg sheet and/or a resin sheet. The so-called prepreg is a general term for composite materials in which synthetic resin plates, glass plates, glass woven fabrics, glass non-woven fabrics, paper, etc. are impregnated with synthetic resins. Examples of preferred insulating resins include epoxy resins, cyanate ester resins, bismaleimide triazine resins (BT resins), polyphenylene ether resins, phenol resins, and the like. In addition, examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resin, polyimide resin, and polyester resin. In addition, based on the viewpoint of improving the insulation of the resin layer, etc., filler particles made of various inorganic particles such as silica and alumina may also be contained. The thickness of the resin layer is not particularly limited, but is preferably 1 μm or more and 1000 μm or less, more preferably 2 μm or more and 400 μm or less, and still more preferably 3 μm or more and 200 μm or less. The resin layer may be composed of multiple layers. A resin layer such as a prepreg sheet and/or a resin sheet can also be provided on a roughened copper foil or a copper foil with a carrier through an undercoating resin layer pre-coated on the roughened surface of the roughened copper foil.

Printed wiring board The roughened copper foil or copper foil with a carrier of the present invention is preferably used in the production of printed wiring boards, and is particularly preferably used in the production of printed wiring boards using the semi-additive method (SAP). That is, according to a preferred aspect of the present invention, a printed wiring board provided with the above-mentioned roughened copper foil or the above-mentioned copper foil with a carrier is provided. By using the roughened copper foil or copper foil with a carrier of the present invention, in the manufacture of printed wiring boards, it is possible to impart sufficient shear strength to the laminate and effectively prevent the circuit from peeling off in the working steps, and to provide protection against The surface profile of electrolytic copper plating is also excellent in etching properties. In addition, by using the above-mentioned roughening treatment copper foil, in the dry film development step of the SAP method, extremely fine dry film resolution can be achieved. Therefore, it is possible to provide a printed wiring board formed by implementing extremely fine circuits. The printed wiring board of this aspect includes a layered structure in which a resin layer and a copper layer are laminated. In the case of the SAP method, the roughened copper foil of the present invention has been removed in step (c) of FIG. 1, so the printed wiring board produced by the SAP method does not include the roughened copper foil of the present invention. It is only the surface contour transferred from the roughened surface of the roughened copper foil. In addition, the resin layer is as described above for the copper-clad laminate system. In short, the printed wiring board can be constructed with conventional layers. For specific examples of printed wiring boards, for example, the roughened copper foil of the present invention is adhered to one or both sides of a prepreg and hardened to form a laminate, and then a single-sided or double-sided printed wiring board of a circuit is formed or the Multi-layered printed wiring boards, etc. In addition, as other specific examples, there are flexible printed wiring boards, COF, TAB tapes, etc. in which the roughened copper foil or copper foil with a carrier of the present invention is formed on a resin film and a circuit is formed. As yet another specific example, a copper foil with resin formed on the roughened copper foil of the present invention or copper foil with a carrier coated with the above resin layer (RCC), and the resin layer is laminated as an insulating adhesive material on the above After the substrate is printed, the roughened copper foil is used as all or a part of the wiring layer to form a build-up wiring board for the circuit by a method such as the improved semi-additive (MSAP) method, subtractive method, etc., or the roughened copper foil is removed The build-up wiring board of the circuit is formed by the semi-additive method (SAP), and the direct buildup on wafer (Direct Buildup On Wafer) of the semiconductor integrated circuit is repeatedly and alternately laminated with resin copper foil and the circuit formed. As a more developed specific example, there are also examples of the antenna element in which the resin-attached copper foil is laminated on the substrate to form a circuit, and the patterned panel/display electronic material or window is laminated on a glass or resin film via an adhesive. Electronic material for glass, electromagnetic wave shielding film coated with conductive adhesive on the roughened copper foil of the present invention, etc. In particular, the roughened copper foil or 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 Figures 1 and 2 can be used. [Example]

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

Examples 1~3 The production and evaluation of copper foil with carrier are as follows.

(1) Preparation of the carrier. The surface is prepared with a titanium electrode polished with #2000 abrasive cloth as the cathode. Also prepare DSA (Dimensional Stability Anode) as the anode. Using these electrodes, they were immersed in a copper sulfate solution with a copper concentration of 80 g/L and a sulfuric acid concentration of 260 g/L, and ^{electrolyzed at a solution temperature of 45° C. and a current density of 55 A/dm 2 to} obtain an electrolytic copper foil with a thickness of 18 μm as a carrier.

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

Carrier organic release layers (3) forming an auxiliary metal layer is formed is immersed in a nickel concentration of nickel produced sulphate 20g / L of solution at a liquid temperature of 45 ℃, pH3, a current density of 5A / dm condition ^2, the organic release The layer is deposited with an amount of nickel equivalent to a thickness of 0.001 μm. In this way, a nickel layer is formed as an auxiliary metal layer on the organic peeling layer.

(4) forming the ultra-thin copper foil forming the auxiliary support impregnated metal layer 60g / L and the copper concentration in the sulfuric acid concentration of 200g / L of copper sulfate solution, a solution temperature of 50 ℃, a current density of 5A / dm ² or more 30A / Electrolysis below dm ² to form an ultra-thin copper foil with a thickness of 1.2 μm on the auxiliary metal layer.

(5) Coarse treatment The precipitation surface of the above-mentioned ultra-thin copper foil is roughened. This roughening treatment is performed by the following three-stage plating. The plating steps of each stage use copper sulfate solution with copper concentration, sulfuric acid concentration, chlorine concentration and 9-phenyl acridine (9PA) concentration shown in Table 1. The liquid temperature shown in Table 1 is shown in Table 2. Electroplating is performed at the current density shown. The energizing time in the first and second stages of plating is set to 4.4 seconds each time, and the energizing time in the third stage of plating is set to 0.6 seconds. In addition, the linear flow velocity of the plating solution for ultra-thin copper foil is 0.25 m/s or more and 0.35 m/s or less. In this way, three types of roughened copper foils of Examples 1 to 3 were produced.

(6) Anti-rust treatment The surface of the roughened layer of the obtained copper foil with a carrier is subjected to anti-rust treatment by zinc-nickel alloy plating treatment and chromate treatment. First use an electrolyte with a zinc concentration of 0.2g/L, a nickel concentration of 2g/L, and a potassium pyrophosphate concentration of 300g/L at a temperature of 40°C and a current density of 0.5A/dm ² on the roughened layer and the surface of the carrier Perform zinc-nickel alloy plating treatment. Next, use a 1g/L aqueous solution of chromic acid to perform chromate treatment on the surface treated with zinc-nickel alloy plating under the conditions of pH 11, liquid temperature 25°C, and current density 1A/dm ^2.

(7) Silane coupling agent treatment The copper foil side surface of the copper foil with a carrier absorbs an aqueous solution containing 3 g/L of 3-aminopropyltrimethoxysilane, and the water is evaporated by an electric heater to perform silane coupling agent treatment. At this time, no silane coupling agent treatment was performed on the carrier side.

(8) Evaluation of the surface of roughened copper foil With respect to the obtained roughened copper foil, various characteristics of the surface profile were evaluated as follows.

(8-1) Observation of roughened particles Obtain the cross-sectional image of the roughened copper foil obtained, and calculate ^{the average value of the ratio L 2} /S and the number of roughened particles per 10 μm of the roughened copper foil as follows.

(8-1-1) Obtaining cross-sectional images Using FIB-SEM equipment (manufactured by SII Technology Co., Ltd., SMI3200SE), FIB (focused ion beam) processing is performed from the surface of the roughened copper foil, and a cross section parallel to the thickness of the copper foil is made, so that the roughened surface is 60 The cross-section is observed by SEM in the direction of ° (magnification: 36000 times), and a cross-sectional image is obtained.

(8-1-2) ^{Calculate the ratio of L 2} /S to take the cross-sectional image of the roughened copper foil 10μm in length into the image analysis software Image-Pro Plus 5.1J (manufactured by Media Cybernetics, Inc.), borrow The function "free curve AO" of the analysis software captures the coarsened particles in the section one by one. After extracting all the roughened particles contained in the cross-sectional image, adjust the contrast so that the inside of the roughened particles becomes white. Next, use the analysis software's function "count/size" to automatically identify the roughened particles that have become bright colors, and use the measurement function to measure the surrounding length L and area S of each roughened particle to calculate the ratio L ² /S. Roughening particles for all embodiments of each of the above operations at different three fields of view, using the ratio of observed / mean S L ² as an average of the sample than L ² / S ratio.

(8-1-3) Number of coarsening particles Measure the number of roughened particles in the field of view in the cross-sectional image and the horizontal width of the field of view, and convert them to the number per length of 10μm. For each case, the measurement was performed in three different fields of view, and the average value was used as the number of coarsened particles per 10 μm in length of the sample.

(8-2) Measurement of ten-point average roughness Rz A laser microscope (manufactured by KYENCE Co., Ltd., VK-9510) equipped with a 150-fold objective lens was used to observe the roughened surface to obtain a field of view image of ^{6550.11 μm 2.} From the obtained visual field image, 10 areas of 10 μm×10 μm are randomly selected in a range that does not overlap each other, and the ten-point average value Rz is measured in accordance with JIS B 0601-1994. The average value of Rz at 10 locations is used as the Rz of the sample.

(9) Production of copper clad laminate Use copper foil with carrier to make copper clad laminate. First, a prepreg (GHPL-830NSF made by Mitsubishi Gas Chemical Co., Ltd., GHPL-830NSF, thickness 0.1mm) is laminated on the surface of the inner substrate to roughen the copper foil with a carrier, and it is hot pressed at a pressure of 4.0 MPa and a temperature of 220°C. After 90 minutes, the carrier was peeled off to produce a copper-clad laminate.

(10) Production of laminates for SAP evaluation Next, after removing all the copper foil on the surface with a sulfuric acid-hydrogen peroxide-based etching solution, degreasing, Pd-based catalyst application, and activation treatment are performed. In this way, electroless copper plating (thickness: 1 μm) was performed on the activated surface to obtain a laminate (hereinafter referred to as a laminate for SAP evaluation) before the dry film was to be bonded by the SAP method. These steps are carried out in accordance with the known conditions of the SAP law.

(11) Evaluation of laminates for SAP evaluation With respect to the above-obtained SAP evaluation laminate, various characteristics were evaluated as follows.

＜Plating circuit adhesion (shear strength)＞ A dry film was attached to the SAP evaluation laminate, and exposed and developed. After the laminate body masked by the developed dry film is pattern-plated to deposit a 14μm copper layer, the dry film is peeled off. The exposed electroless copper plating was removed with a sulfuric acid-hydrogen peroxide-based etching solution to prepare a circuit sample for measuring shear strength with a height of 15 μm, a width of 10 μm, and a length of 150 μm. Using a bonding strength tester (manufactured by Nordson DAGE, 4000Plus Adhesion Tester), the shear strength when the circuit sample for shear strength measurement was overwhelmed from the lateral direction was measured. That is, as shown in FIG. 6, the laminated body 134 forming the circuit 136 is placed on the movable table 132, and the movable table 132 is moved in the direction of the arrow in the figure, and the circuit 136 is touched on the pre-fixed detector 138, A lateral force is applied to the side surface of the circuit 136 to overwhelm it, and the force (gf) at this time is measured by the detector 138 and taken as the shear strength. At this time, the test type is set as a destruction test, and the measurement is performed under the conditions of a test height of 10 μm, a lowering speed of 0.050 mm/s, a test speed of 100.0 μm/s, a tool movement amount of 0.05 mm, and a destruction recognition point of 10%.

＜etchability＞ The substrate for SAP evaluation was etched step by step with a sulfuric acid-hydrogen peroxide-based etching solution at 0.2 μm, and the amount (depth) until the copper on the surface was completely disappeared was measured. This measurement was performed by confirming with an optical microscope (500 times). More specifically, the operation of confirming the presence or absence of copper with an optical microscope every 0.2 μm etching is repeated, and the value (μm) obtained by (the number of times of etching)×0.2 μm is used as an index of the etching property. For example, the etching property of 1.2 μm means that by performing etching of 0.2 μm six times, the remaining copper is not detected by an optical microscope (that is, 0.2 μm×6 times=1.2 μm). That is, the smaller the value means that the copper on the surface can be removed with fewer etchings. In other words, the smaller the value, the better the etching properties.

＜Dry film resolution (minimum L/S)＞ Laminate a 25μm thick dry film on the surface of the SAP evaluation laminate, and use a mask that forms a line/space (L/S) pattern from 2μm/2μm to 15μm/15μm for exposure and development. The exposure at this time is set to 125mJ. The surface of the sample after imaging is observed with an optical microscope (magnification: 500 times), and the smallest (that is, the smallest) L/S of the L/S that can be developed without any problem is used as the index of dry film resolution . For example, the minimum L/S=10μm/10μm of the index of dry film resolution evaluation means that L/S from 15μm/15μm to 10μm/10μm can be resolved without problems. For example, when the image can be resolved without problems, a sharp contrast is observed between the dry film patterns. On the other hand, when the resolution cannot be performed well, a darkened portion is observed between the dry film patterns, and the sharp contrast cannot be observed.

result The evaluation results obtained in Examples 1 to 3 are summarized in Table 3.

10‧‧‧Roughened copper foil 10a‧‧‧Base surface 12‧‧‧Roughened particles 12a‧‧‧Protrusion 12p‧‧‧Contour line 12s‧‧Line segment 110‧‧‧Roughened copper foil 111‧‧ ‧Insulating resin substrate 111a. Dry film 117. ‧Circuit 138‧‧‧Detector c ₁ ‧‧‧Contact c ₂ ‧‧‧Contact

Figure 1 is a diagram used to illustrate the step flow of the SAP method, showing the first half of the steps (steps (a) ~ (d)). Figure 2 is a diagram used to illustrate the step flow of the SAP method, showing the second half of the steps (steps (e) ~ (h)). FIG. 3A is a schematic cross-sectional view showing the side surface of the circuit in the longitudinal direction when covered with solder resist. Figure 3B shows a schematic cross-sectional view of the circuit without being covered with solder resist. 4 is a schematic cross-sectional view showing the roughened surface of the roughened copper foil of the present invention. 5 is a schematic cross-sectional view for explaining the length L and the area S around the roughened particles of the roughened copper foil of FIG. 4. Fig. 6 is a schematic diagram for explaining the method of measuring the shear strength.

10‧‧‧Roughened copper foil

10a‧‧‧Base surface

12‧‧‧Coarse particles

12a‧‧‧Protrusion

Claims (12)

A roughened copper foil, which is a roughened copper foil with a roughened surface on at least one side, the roughened surface is provided with a plurality of roughened particles, and the roughened copper foil has a cross section of 10 μm in length. The ratio of the square of the surrounding length L (μm) of the particles to the area S (μm ² ) of the ^{roughened particles is L 2} /S, and the average value of L 2 /S is 16 or more and 30 or less, and the ten-point average roughness of the roughened surface The degree Rz is 0.7 μm or more and 1.7 μm or less. Such as the roughening treatment copper foil of claim 1, wherein the aforementioned ratio L ² /S is 19 or more and 27 or less. The roughened copper foil of claim 1, wherein the number of roughened particles in a cross section of 10 μm in length of the roughened copper foil is 20 or more and 70 or less. Such as the roughened copper foil of claim 1, which is used to transfer the uneven shape to the insulating resin layer for printed wiring boards. Such as the roughening treatment copper foil of claim 1, which is used to produce printed wiring boards by the semi-additive method (SAP). A copper foil with a carrier, which is provided with a carrier, a peeling layer provided on the carrier, and a roughening treatment such as any one of claims 1 to 5 provided on the peeling layer with the roughening treatment surface as the outer side Copper foil. A copper-clad laminated board provided with the roughened copper foil according to any one of claims 1 to 5. A copper-clad laminated board provided with the copper foil with a carrier as in claim 6. A printed wiring board obtained by using the roughening treatment copper foil as in any one of claims 1 to 5. A printed wiring board obtained by using copper foil with a carrier as in claim 6. A method of manufacturing a printed wiring board, characterized in that the printed wiring board is manufactured by using the roughened copper foil as in any one of claims 1 to 5. A method of manufacturing a printed wiring board, which is characterized by using copper foil with a carrier as in claim 6 to manufacture a printed wiring board.

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