JP5858849B2 - Metal foil - Google Patents

Description

  The present invention relates to a metal foil for a printed wiring board. Moreover, this invention relates to the laminated body of a metal foil and resin, especially a laminated body suitable as a solar cell back surface protection sheet and a solar cell back surface wiring sheet.

  Conventionally, as a typical industrial application of a laminate in which a metal foil and a resin are laminated, there is a copper-clad laminate for a flexible printed wiring board, a polyimide material as a resin, and a copper foil as a metal foil. It was mainly used. In addition to these technologies, in recent years, as a new industrial application that utilizes the good electrical and thermal conductivity of copper foil, copper foil and various resins other than polyimide are bonded via an adhesive to form a sheet. The technology used as a structural material, circuit material or heat dissipation material is being researched and developed.

  As such a technique, for example, as shown in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-170771), a plastic film is provided on both sides of the copper foil for the purpose of improving the thermal conductivity of the solar cell back surface protection sheet. A solar cell back surface protective sheet having a laminated structure has been proposed.

  Further, for example, as shown in Patent Document 2 (Japanese Patent Application Laid-Open No. 2011-0661151), the copper foil in the solar battery back surface protective sheet is patterned into a circuit shape, and is provided on the pattern portion and the solar battery cell back surface. A solar cell backside wiring sheet that also functions as a wiring material by being connected to the terminal portion thus developed has been developed.

  On the other hand, copper foil has heretofore been mainly used as a circuit material for printed wiring boards. A copper foil and a thermosetting insulating resin are thermocompression-bonded at a temperature higher than the glass transition temperature of the resin to form a copper-clad laminate, and then manufactured through a process of forming a conductor pattern on the copper foil surface by etching. It is common. As a technique for improving the adhesion between the copper foil and the thermosetting insulating resin, a surface treatment for forming irregularities on the surface of the copper foil called a roughening treatment is generally performed. For example, by using a copper sulfate acidic plating bath on the rough surface (deposition surface) of the electrolytic copper foil, a large number of copper particles are electrodeposited in a dendritic or small spherical shape to form fine irregularities, and the anchoring effect (also called anchor effect) There is a method for improving the adhesion. In order to further improve the adhesion strength after the roughening treatment, formation of a Cr oxide film by chromate treatment, surface treatment with a silane coupling agent, and the like are generally performed.

  In conventional copper foils for printed wiring boards, there are many technologies aimed at improving the adhesion between copper foil and resin by paying attention to the surface roughness, but the index indicating the surface roughness of copper foil has traditionally been JIS A number of techniques have been proposed that have a ten-point average roughness Rz defined in B0601-1994, and obtain adhesion to the resin by controlling Rz of the adhesive surface with the thermosetting resin. For example, patent document 3 (Unexamined-Japanese-Patent No. 2005-48269) etc. correspond.

  However, when considering the essence of adhesion by the anchoring effect, it is most important to optimize the surface area of the copper foil for the target adhesive. For this reason, it is not sufficient to control the Rz representing the height of the surface irregularities of the copper foil in order to discuss the adhesion between the copper foil and the adhesive, and it is necessary to consider the intervals between the irregularities. In general, the surface area increases as the height difference of the unevenness increases, that is, as Rz increases and the unevenness interval decreases. As typical indexes representing the unevenness interval, there are an average interval Sm of unevenness and an average interval S of local peaks defined in JIS B0601-1994.

  For example, in Patent Document 4 (Japanese Patent Application Laid-Open No. 2011-216598), Sm is controlled in addition to Rz, and the ratio of Rz to Sm (Rz / Sm) is in the range of 1.5 to 3.5. A high-frequency circuit board obtained by laminating a thermoplastic liquid crystal polymer film has been proposed, whereby high adhesion between a metal foil (commercially available copper foil in the examples) and a liquid crystal polymer can be obtained. Yes. Patent Document 5 (Japanese Patent Laid-Open No. 2011-219790) proposes a copper foil for a copper clad laminate in which the ranges of Rz and S are defined, and the copper foil measured using a violet laser having a wavelength of 408 nm It is described that S of the roughened particles is 210 nm or less.

JP 2009-170771 A JP 2011-0661151 A JP 2005-48269 A JP2011-216598A JP 2011-219790 A

  Thus, for copper foils for printed wiring boards, optimization of surface roughness has been sought in order to improve the adhesion to the resin. However, when the roughened copper foil conventionally used for printed wiring boards is laminated with a resin via an adhesive, not only sufficient adhesion between the copper foil and the adhesive cannot be obtained, When the laminated sheet is placed under a high temperature and high humidity condition for a long time, there is a problem that the adhesion is greatly lowered. Furthermore, there is a problem that the thickness of the adhesive becomes unnecessarily thick and uneconomical.

  A possible cause of such a problem is that the surface of the copper foil having fine irregularities and the adhesive are not in close contact with each other with a sufficient contact area. In Patent Document 4 (Japanese Patent Application Laid-Open No. 2005-48269), Sm is controlled in addition to Rz, but controlling Sm in addition to Rz completely explains the essence of adhesion between copper foil, adhesive and resin. I can't say that. This is because Sm only represents the average value of the peak-and-valley period of irregularities, and the presence of a large number of minute irregularities in the period is not considered.

  This is understood from FIG. FIGS. 1A and 1B are schematic diagrams of a surface roughness curve having the same Sm. In FIG. 1B, finer irregularities exist in the valley period of the irregularities. Since the surface area of (b) is larger than that of (a), it is easily considered that a larger anchoring effect can be obtained. The index of the surface roughness representing the interval between each fine unevenness is the above-mentioned average interval S between the local peaks. S is the average of the intervals between the vertices of the individual peaks of the surface roughness curve schematically represented in FIG. Therefore, it is more important to appropriately control Rz and S.

  In this regard, Patent Document 5 (Japanese Patent Application Laid-Open No. 2011-219790) proposes a copper foil for a copper-clad laminate in which Rz and S ranges are defined, and measurement is performed using a violet laser having a wavelength of 408 nm. S of the roughened copper foil particles is controlled to 210 nm or less. And since the intervals of the roughening particles are close, there are many roughening particles per unit area. For this reason, the adhesion surface area with the resin substrate is increased, and an efficient anchoring effect is obtained. It is marked as preferred. However, Patent Document 5 does not discuss the adhesiveness between the copper foil and the resin via the adhesive, and the range of Rz and S of the copper foil described in the literature is the adhesion with the adhesive. The present inventor has found a problem that when considering, S is too small to obtain sufficient adhesion.

  The present invention was created in view of the above circumstances, and an object of the present invention is to provide a metal foil excellent in adhesiveness with an adhesive. Another object of the present invention is to provide a laminate of the metal foil and the resin having high adhesiveness bonded through an adhesive. Furthermore, this invention makes it another subject to provide the solar cell back surface protection sheet or solar cell back surface wiring sheet provided with the said laminated body.

  As a result of intensive studies, the inventor has found that the ten-point average roughness Rz on the bonding surface with the adhesive is in the range of 2.0 μm or more and 6.0 μm or less, and the ratio with the average interval S of the local peaks ( It has been found that a metal foil having Rz / S) in the range of 2.0 or more and 6.0 or less is excellent in adhesiveness with an adhesive.

  The present invention has been completed based on the above findings. In one aspect, at least one surface has a ten-point average roughness Rz of 2.0 μm or more and 6.0 μm or less, and the local summit A metal foil having a ratio (Rz / S) with an average interval S of 2.0 or more and 6.0 or less.

  In one embodiment of the metal foil according to the present invention, the metal foil is a copper foil.

  In another embodiment of the metal foil according to the present invention, the average distance S between the local peaks is not less than 0.5 μm and not more than 3.0 μm.

  In still another embodiment of the metal foil according to the present invention, the ratio (Rz / Sm) of the ten-point average roughness Rz to the average interval Sm of the unevenness is 0.5 or more and 4.0 or less.

  In still another embodiment of the metal foil according to the present invention, the average interval Sm between the irregularities is 1.0 μm or more and 4.0 μm or less.

  In yet another embodiment of the metal foil according to the present invention, on at least one surface, a coating layer made of a Cu-Zn alloy, a coating layer made of a Cu-Ni alloy, a coating layer made of a Co-Ni alloy, One or a plurality of surface coating layers are formed of a coating layer made of a Ni—Zn alloy and a rust-proof coating layer made of Cr oxide.

  In still another embodiment of the metal foil according to the present invention, a silane coupling agent treatment layer is formed on the surface coating layer.

  In still another embodiment of the metal foil according to the present invention, the metal foil is an electrolytic copper foil.

  In another aspect, the present invention is a laminate in which the metal foil according to the present invention and a resin are bonded together with an adhesive.

  In one embodiment of the laminated board according to the present invention, the resin is a plastic film.

  In yet another aspect, the present invention is a wiring board in which a metal foil of a laminated board according to the present invention is partially etched to form a circuit.

  In yet another aspect, the present invention is a solar cell back surface protective sheet or a solar cell back surface wiring sheet obtained by processing the laminate according to the present invention.

In still another aspect of the present invention, the electrolyte containing copper and sulfuric acid contains chloride ions of 20 to 100 mg / L, gelatin of 0.2 to 6.0 mg / L, and at least one of thiourea and active sulfur-containing substances. It is a manufacturing method of copper foil including the process of adding the seed total 0.01-2.0 mg / L and electrodepositing copper on the conditions of 10-90 A / dm < ² > current density.

In still another aspect of the present invention, the electrolyte containing copper and sulfuric acid contains chloride ions of 20 to 100 mg / L, gelatin of 0.2 to 6.0 mg / L, and at least one of thiourea and active sulfur-containing substances. A foil forming step of adding a total of 0.01 to 2.0 mg / L of seeds and electrodepositing copper under conditions of a current density of 10 to 90 A / dm ² to obtain an untreated copper foil, and the untreated copper foil A coating layer made of Cu—Zn alloy, a coating layer made of Cu—Ni alloy, a coating layer made of Co—Ni alloy, a coating layer made of Ni—Zn alloy, and a rust-proof coating made of Cr oxide It is a copper foil manufacturing method including a surface treatment step of forming a silane coupling agent layer on the surface coating layer after forming any one or a plurality of surface coating layers among the layers.

In still another aspect of the present invention, the electrolyte containing copper and sulfuric acid contains chloride ions of 20 to 100 mg / L, gelatin of 0.2 to 6.0 mg / L, and at least one of thiourea and active sulfur-containing substances. A foil forming step of adding a total of 0.01 to 2.0 mg / L of seeds and electrodepositing copper under conditions of a current density of 10 to 90 A / dm ² to obtain an untreated copper foil, and the untreated copper foil A coating layer made of a Cu—Zn alloy, a coating layer made of a Cu—Ni alloy, a coating layer made of a Co—Ni alloy, a coating layer made of a Ni—Zn alloy, and Cr A method for producing a copper foil comprising a surface treatment step of forming any one or a plurality of surface coating layers of an anticorrosive coating layer comprising an oxide and then forming a silane coupling agent layer on the surface coating layer is there.

  In still another aspect, the present invention is a method for manufacturing a laminated board including a step of bonding a copper foil manufactured by the method for manufacturing a copper foil according to the present invention and a resin through an adhesive.

  Since the metal foil which concerns on this invention has high adhesiveness with an adhesive agent, when adhering with resin through an adhesive agent, the outstanding adhesiveness is shown. Therefore, the laminate of the metal foil and the resin according to the present invention can be suitably used as, for example, a solar cell back surface protection sheet and a solar cell back surface wiring sheet.

It is a schematic diagram for demonstrating the difference of the average space | interval Sm of an unevenness | corrugation, and the average space | interval S of a local peak.

  Although it does not specifically limit as metal foil used in this invention, Typically, copper foil can be used. However, it goes without saying that metal foils other than copper foil can be used if Rz and the ratio of Rz to S (Rz / S) are within the range shown in the present invention. For example, nickel foil and aluminum foil can be used. An alloy foil can also be used.

  Copper foils are roughly classified into electrolytic copper foils and rolled copper foils depending on the manufacturing method. Both are often used as circuit materials for printed wiring boards. In general, the electrolytic copper foil is manufactured by electrolytically depositing copper from a copper sulfate plating bath onto a titanium or stainless steel rotating drum in a foil manufacturing process. At this time, the surface on the rotating drum side is generally referred to as a shiny surface (or drum surface), and the surface in contact with the electrolyte on the opposite side is generally referred to as a mat surface (or precipitation surface or rough surface). Thereafter, in order to improve the adhesion strength with the resin, in general, one or both surfaces are subjected to a roughening treatment, a rust prevention treatment, and a silane coupling agent treatment in the surface treatment step.

  The rolled copper foil is manufactured by repeating plastic working and heat treatment with a rolling roll (rolling process). Thereafter, generally, roughening treatment, rust prevention treatment, and silane coupling agent treatment are performed in the surface treatment step in the same manner as the electrolytic copper foil.

  As the composition of the copper foil, in addition to high-purity copper such as electrolytic copper, electroless copper, tough pitch copper and oxygen-free copper, which are usually used as conductor patterns of printed wiring boards, for example, Sn-containing copper, Ag-containing copper, Cr, Zr Alternatively, a copper alloy such as a copper alloy to which Mg or the like is added, or a Corson copper alloy to which Ni or Si is added can also be used. In addition, when the term “copper foil” is used alone in this specification, a copper alloy foil is also included.

  There is no restriction | limiting in particular also about the thickness of the copper foil which can be used for this invention, What is necessary is just to adjust to the thickness suitable for practical use suitably. For example, it can be about 2 to 300 μm. However, when the copper foil of the present invention is also used as a circuit material, the copper foil thickness is 5 to 105 μm, preferably 12 to 70 μm, and typically about 18 to 35 μm.

  In the metal foil according to the present invention, Rz on at least one surface is 2.0 μm or more and 6.0 μm or less, and the ratio of Rz to S (Rz / S) is 2.0 or more and 6.0 or less. Is one of the features. In the present invention, Rz indicates the ten-point average roughness defined by JIS B0601-1994, and S indicates the average interval S of the local peaks defined by JIS B0601-1994.

  If Rz is larger than 6.0 μm, the adhesive may not enter the valleys of the copper foil surface irregularities, and the adhesion strength may decrease. In addition, since it is necessary to fill the concavo-convex portion with a large amount of adhesive, there is a problem in that the amount of adhesive to be used is unnecessarily increased and uneconomical. Therefore, Rz is defined to be 6.0 μm or less. Rz is preferably 5.5 μm or less.

  Even when Rz is smaller than 2.0 μm, the necessary and sufficient adhesive strength with the adhesive cannot be obtained. This is because the contact area between the metal foil and the adhesive is small, so that adhesion due to the anchoring effect (anchor effect) cannot be obtained sufficiently. Therefore, Rz is defined as 2.0 μm or more. Rz is preferably 2.5 μm or more, more preferably 3.0 μm or more.

  In order to further increase the adhesion strength between the metal foil and the adhesive, it is necessary to consider not only the range of Rz but also the ratio of Rz to S (Rz / S). Conventional copper foils used for printed wiring board applications tend to have a Rz / S higher than 6.0. This means that the unevenness interval in the horizontal direction on the surface is too small with respect to the height of the unevenness. Also in this case, the adhesive does not enter the concavo-convex portion, and sufficient adhesion strength cannot be obtained. Therefore, in this invention, ratio (Rz / S) with the local peak top average space | interval S which is a parameter | index showing the horizontal space | interval of an unevenness | corrugation was prescribed | regulated to 6.0 or less. Rz / S is preferably 5.5 or less.

  Also, in the case of a low profile copper foil or a double-sided smooth foil for a lithium ion battery negative electrode current collector used for a printed wiring board with a particularly narrow circuit width, Rz / S tends to be smaller than 2.0. However, the adhesion strength with the adhesive is low. This is because the height of the unevenness is too small compared to the interval between the unevennesses, so that adhesion due to the anchoring effect (anchor effect) cannot be obtained sufficiently. Therefore, in this invention, ratio (Rz / S) with the local peak top average space | interval S which is a parameter | index showing the horizontal space | interval of an unevenness | corrugation was prescribed | regulated to 2.0 or more. Rz / S is preferably 2.2 or more, more preferably 3.5 or more.

  Further, the local summit average interval S itself is indirectly defined by defining Rz and Rz / S. However, if S is too small, the adhesive cannot enter the concavo-convex portion, so that S is 0.00. It is preferably 5 μm or more, and more preferably 1.0 μm or more. Similarly, the upper limit of S is indirectly defined by similarly defining Rz and Rz / S, but is preferably 3.0 μm or less, and more preferably 2.5 μm or less. When S is larger than this range, the adhesion strength with the adhesive is lowered.

  In order to increase the adhesion strength between the metal foil and the adhesive, the ratio of the ten-point average roughness Rz to the average interval Sm (Rz / Sm) is preferably 0.5 or more and 4.0 or less. More preferably, it is 0 or more and 2.0 or less. Moreover, it is preferable that the average space | interval Sm of an unevenness | corrugation is 1.0 to 4.0 micrometer, and it is more preferable that it is 2.0 to 3.5 micrometer. However, it is necessary to adjust both Rz and Rz / S to an appropriate range, as described above, because it is not possible to obtain sufficient adhesion strength simply by defining them. Sm refers to the average interval of irregularities defined by JIS B0601-1994.

  As a method for producing a metal foil having the optimum range of Rz and Rz / S of the present invention, various roughening treatments are applied to the surface of the metal foil made of Cu, Ni, Fe, Al, etc. obtained by electrolysis or rolling. Can be considered. Specifically, as the roughening treatment, a roughening treatment by electrodeposition of fine particles, chemical etching with a chemical agent, or an anodic oxidation method can be used.

In particular, in order to produce a copper foil having the optimum range of Rz and Rz / S of the present invention, it is preferable to optimize the production conditions of the foil making process. Specifically, it is desired that various additives are added to the electrolytic solution of copper sulfate to perform foil formation under predetermined electrolysis conditions. As additives, gelatin with glue as a representative example is 0.2 to 6.0 mg / L, preferably 2.0 to 5.5 mg / L, and chloride ion is 20 to 100 mg / L, preferably 20 to Use in a concentration range of 60 mg / L. In addition to this, by adding the total concentration of at least one kind of thiourea and active sulfur-containing substance to 0.01 to 2.0 mg / L, preferably 0.1 to 1.5 mg / L, ten-point average coarseness is added. The height Rz and the local peak average interval S can be adjusted to the optimum ranges. As electrolysis conditions, the liquid temperature is 40 to 70 ° C., preferably 50 to 65 ° C., the current density is 10 to 90 A / dm ² , preferably 50 to 90 A / dm ² , and the linear flow rate of the electrolyte is 1.0 to 5. It is suitable to carry out in the range of 0 m / second, preferably 3.0 to 5.0 m / second.
The sulfuric acid concentration in the electrolytic solution is not limited, but is preferably 50 to 150 g / L, 80 to 120 g in order to increase the conductivity of the electrolytic solution to lower the electrolytic voltage and reduce power consumption. / L is more preferable.
The copper concentration in the electrolytic solution is not limited, but is preferably 50 to 150 g / L, and more preferably 80 to 120 g / L in order to improve productivity during commercial production.

  The surface of the metal foil according to the present invention may be further subjected to various heat and rust preventive surface treatments or silane coupling agent treatments for the purpose of preventing oxidation discoloration of the metal foil and improving adhesion strength with the adhesive. . For example, in one embodiment of the metal foil according to the present invention, a Cu—Zn alloy, a Cu—Ni alloy, a Ni—Co alloy, a Ni—Zn alloy, a Cr oxide is provided on a surface that satisfies at least the above-described surface roughness definition. Any one or more of the coating treatment layers made of may be laminated in combination. For example, when a coating treatment layer made of a Cu—Zn alloy is formed and a coating treatment layer made of a Ni—Zn alloy is laminated thereon, a coating treatment layer of a Cu—Zn alloy is formed, and a Cr oxide is formed thereon. In the case of laminating a coating treatment layer consisting of Cu-Zn alloy, a coating treatment layer consisting of Ni-Zn alloy and a coating treatment layer consisting of Cr oxide are sequentially laminated thereon, The case where the coating process layer which consists of a Ni-Zn alloy is formed, and the coating process layer which consists of Cr oxides on it is mentioned.

The total thickness of the coating treatment layer is preferably in a range that does not change Rz and Rz / S obtained in the foil-making process, and the coating amount of the entire coating treatment layer is preferably 0.01 to 10 mg / dm ² , more preferably It is suitable to set it as 0.1-6.0 mg / dm < ² >, More preferably, it is the range of 1.0-5.0 mg / dm < ² >.

  In still another embodiment of the copper foil according to the present invention, a surface coating with a silane coupling agent may be performed on the coating treatment layer. The surface coating layer by the silane coupling agent is effective because the metal (copper foil) surface and the organic material (adhesive) surface are cross-linked and the mutual adhesion is improved.

  The silane coupling agent layer usually has a thickness of several to several tens of atoms and is so thin that it does not greatly change the values of Rz and Rz / S of the copper foil.

  The metal foil which concerns on this invention shows the adhesiveness outstanding with the adhesive agent by having the specific surface roughness mentioned above. The adhesive used for laminating the metal foil and the resin is not limited, but the effect is high for, for example, an epoxy resin adhesive, a urethane resin adhesive, and a polyester resin adhesive. Although it can also be used for polyimide adhesives, the adhesive strength of the polyimide adhesive is high even in conventional copper foil, so that the excellent adhesive strength of the present invention is exhibited significantly, At the time of joining with an adhesive other than the polyimide adhesive.

  The metal foil which concerns on this invention can form a laminated board by bonding together with resin through an adhesive agent. A copper foil may be used as the metal foil to make a copper-clad laminate by thermocompression bonding with a resin, particularly an insulating thermosetting resin. The material of the resin is not limited, but fluorine-containing resins such as polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinyl acetate resin, polyethylene terephthalate (PET), Polyester resins such as polybutylene terephthalate (PBT) and polyethylene naphthalate (PEN), polyolefin resins such as polypropylene, polyethylene, and polyphenylene sulfide (PPS) can be appropriately selected and used. Examples of the insulating thermosetting resin include, but are not limited to, an epoxy resin and a bismaleimide-triazine resin. Of course, it can also be bonded to polyimide.

  There is no restriction | limiting in particular in the thickness of resin, What is necessary is just to change suitably according to a use, However, It can be set as the thickness which is flexible like a plastic film, for example, 10-1000 micrometers.

  The laminated board can be processed into a wiring board on which a circuit is formed by partially etching a metal foil, and can be used as a printed wiring board or a solar cell backside wiring sheet. The laminated plate can be processed to form a solar cell back surface protective sheet.

  Examples of the present invention are shown below. These are provided for better understanding of the present invention, and are not intended to limit the present invention to the examples described below.

(Foil making process)
Electrodeposition was carried out on a stainless steel cylindrical cathode under the electrolytic solution and electrolysis conditions shown below to obtain a copper foil having a predetermined thickness. In all Examples and Comparative Examples, an electrolytic copper foil having a thickness of 35 μm (however, Example 11 was an aluminum foil).

(Electrolytic solution composition in the foil making process)
Cu (as Cu ²⁺ ): 100 g / L
H ₂ SO ₄ : 100 g / L
As additives, Cl (as chloride ions), glue, and thiourea were added at each addition amount listed in Table 1.

(Electrolytic conditions for the foil making process)
Liquid temperature: 57 ° C
Current density: 40-80 A / dm ²
Electrolyte flow rate: 4.0 m / sec

  In Example 11, an aluminum foil having a thickness of 20 μm obtained by rolling was used as a metal foil other than a copper foil. Rz of the surface to be bonded to the adhesive was measured with a surf coder SE-3C manufactured by Kosaka Laboratory, and was 1.0 μm before the surface treatment.

(Roughening treatment)
In Examples 6 to 8 and 11, the matte surface of the copper foil and the surface of the aluminum foil obtained in the foil-making process were subjected to the following two-step roughening treatment.

(Roughening process at the first stage)
The purpose of the first stage roughening treatment is to generate nuclei of roughened particles on the surface of the metal foil by electrodepositing Cu fine particles at a current density exceeding the limit current density of copper ion diffusion on the outermost surface of the metal foil. It is.
(Electrolytic solution composition)
Cu (as Cu ²⁺ ): 10-30 g / L
H ₂ SO ₄ : 50 to 150 g / L
As: 1-2000 mg / L
W: 1 to 100 mg / L
(Roughening conditions)
Liquid temperature: 20-50 degreeC
Current density: 20 to 100 A / dm ²
Energizing time: 1-10 seconds

(Roughening process in the second stage)
The purpose of the second stage roughening treatment is to grow the roughened particle nuclei by applying smooth plating on the nuclei of the coarsened particles generated in the first stage roughening treatment, and to obtain a roughened particle having a predetermined size. To make particles.
(Electrolytic solution composition)
Cu (as Cu ²⁺ ): 20-60 g / L
H ₂ SO ₄ : 50 to 150 g / L (roughening conditions)
Liquid temperature: 30-60 degreeC
Current density: 1 to 50 A / dm ²
Energizing time: 1-10 seconds

(Surface treatment process)
In Examples 1-8 and 10-11, the surface coating treatment shown below on one side of the matte surface (rough surface, precipitation surface) or aluminum foil (Example 11) of the copper foil obtained in the foil-making process. One or more of (a), (b), (c), (d), and (e) were selected and processed. Table 1 shows combinations of surface treatments applied in each example. The coating amount of each surface coating treatment layer was calculated by dissolving the surface coating layer with dilute nitric acid and then measuring the concentration of the coating treatment layer component element in the solution by the ICP-AES method.
(A) Cu—Zn alloy plating treatment (electrolyte composition, pH)
NaCN: 10-30 g / L
NaOH: 40 to 100 g / L
Cu (CN) ₂ : 60 to 120 g / L
Zn (CN) ₂ : 1 to 10 g / L
pH: 10-13
(Electrolysis conditions)
Liquid temperature: 50-80 degreeC
Current density: 10 A / dm ²
Plating time: 4 seconds Coating amount: 5.0 mg / dm ²
(B) Ni—Zn alloy plating treatment (electrolyte composition, pH)
Zn (as Zn ²⁺ ): 12-25 g / L
Ni (as Ni ²⁺ ): 1-8 g / L
pH: 2.0-4.0
(Electrolysis conditions)
Liquid temperature: 25-50 degreeC
Current density: 10 A / dm ²
Plating time: 2 seconds Coating amount: 1.5 mg / dm ²
(C) Cu—Ni alloy plating treatment (electrolyte composition, pH)
Cu (as Cu ²⁺ ): 0.01 to 5.0 g / L
Ni (as Ni ²⁺ ): 5 to 25 g / L
pH: 2.0-4.0
(Electrolysis conditions)
Liquid temperature: 25-50 degreeC
Current density: 5 A / dm ²
Plating time: 2 seconds Coating amount: 1.0 mg / dm ²
(D) Co-Ni alloy plating treatment (electrolyte composition, pH)
Co (as Co ²⁺ ): 0.1-6.0 g / L
Ni (as Ni ²⁺ ): 5 to 20 g / L
pH: 2.0-4.0
(Electrolysis conditions)
Liquid temperature: 25-50 degreeC
Current density: 5 A / dm ²
Plating time: 3 seconds Coating amount: 3.0 mg / dm ²
(E) Electrolytic chromate treatment (electrolyte composition, pH)
_{K 2 Cr 2 O 7: 2.0~6.0g} / L
Zn (as Zn ²⁺ ): 0 to 0.5 g / L
Na ₂ SO ₄ : 5 to 15 g / L
pH: 3.5-5.0
(Electrolysis conditions)
Liquid temperature: 20-60 degreeC
Current density: 2.0 A / dm ²
Plating time: 2 seconds Coating amount: 0.15 mg / dm ²

Finally, the following silane coupling agent treatment was performed on the coating treatment layer.
Silane Coupling Agent Treatment A 0.2 vol% solution of 3-glycidoxypropyltriethoxysilane was spray-coated and then dried in air at a temperature of 100 ° C. or higher for 1 to 10 seconds.

(Surface roughness measurement)
The ten-point average roughness Rz, local peak average interval S, and average interval Sm of irregularities of the mat surface of the metal foil thus prepared were measured. Ten-point average roughness Rz was measured with a surf coder SE-3C manufactured by Kosaka Laboratory. The local peak top average interval S and the uneven average interval Sm were measured using VK-8510 manufactured by Keyence Corporation. The measurement method used was a line roughness-JIS94 mode. The measurement results are shown in Table 1.

(Production of laminated sheets)
Furthermore, in order to measure the adhesion strength between the produced metal foil and the adhesive, a laminated sheet of the metal foil and the plastic film was produced according to the following procedure.
(Plastic film)
In Examples 1 to 9 and 11 and Comparative Examples 1 to 4, Lumirror (thickness: 200 μm) manufactured by Toray Industries, Inc. was used as a polyethylene terephthalate (PET) film.
(adhesive)
The adhesive used was a mixture of Toyo Morton Co., Ltd .: two-component mixed adhesive (main agent: polyester polyol AD-76P1) / (curing agent TCS-4277) and ethyl acetate. The mixing ratio (volume basis) was AD-76P1: TCS-4277: ethyl acetate = 7.5: 1.0: 6.5.
(Applying adhesive)
On the PET film, the adhesive was uniformly applied so as to have a thickness of 15 μm. The PET film coated with the adhesive was heated in a dry air atmosphere at 90 ° C. for 3 minutes to volatilize the solvent.
(Lamination method)
The surface coating treated surface of the metal foil and the adhesive coated surface of the PET film were pressure-bonded using a rubber roller to form a laminated sheet of the metal foil and the PET film.
(Thermosetting method)
The laminated sheet was heated in a dry air atmosphere at 100 ° C. for 10 hours to cure the adhesive.

  In Example 10 and Comparative Example 5, a polyimide resin is used as a resin constituting the laminate and an adhesive, and a laminated sheet is obtained by thermocompression bonding with a hot press machine at a lamination temperature of 240 ° C. and a pressure of 2.5 Mpa. Produced.

(Wiring sheet production)
The metal foil on the produced laminated sheet was etched using an iron chloride-hydrochloric acid etching solution to obtain a circuit wiring sheet. The circuit width was 10 mm for measuring the adhesion strength described below.

(Adhesion strength measurement)
The adhesion strength between the metal foil and the adhesive was measured using the 90 degree peel strength method defined in JIS-C6481. For the measurement, Autograph AGS-J manufactured by Shimadzu Corporation was used. The measurement results are shown in Table 1.

(Examples 1 to 11)
In Examples 1 to 11, the ten-point average roughness is 2.6 to 5.6 μm, the local peak top average interval S is 1.0 to 1.3 μm, and the Rz / S ratio is 2.2 to 5.5. became. The adhesion strength between the copper foil and the aluminum foil and the adhesive is 0.45 to 0.72 kN / m, which is sufficient.

(Comparative Example 1)
In Comparative Example 1, after the foil was made without adding thiourea in the electrolytic solution in the foil-making process, the matte surface of the copper foil was subjected to roughening treatment, Cu-Zn alloy plating treatment, chromate treatment, and silane coupling agent. Processing is performed in order. The difference from Example 1 is that thiourea is not added and a roughening treatment is performed in the foil-making process. Since thiourea is not added to the electrolytic solution in the foil-making process, the surface roughness Rz is larger than 6.0 μm, and Rz / S is also larger than 6.0. The adhesion strength between the copper foil and the adhesive was 0.40 kN / m. Moreover, many bubbles existed at the interface between the copper foil and the adhesive.

(Comparative Example 2)
In Comparative Example 2, after the foil was made without adding glue to the electrolytic solution in the foil making process, the mat surface of the copper foil was subjected to Ni-Zn alloy plating treatment, chromate treatment and silane coupling agent treatment in this order. It is. The difference from Example 5 is that no glue is added in the foil-making process. When no glue was added to the electrolytic solution in the foil making process, Rz was smaller than 2.0 μm and Rz / S was smaller than 2.0. The adhesion strength between the copper foil and the adhesive was 0.20 kN / m.

(Comparative Example 3)
In Comparative Example 3, after the foil was made without adding chloride ions in the electrolytic solution in the foil-making process, the Cu-Zn alloy plating treatment, the chromate treatment, and the silane coupling agent treatment were sequentially performed on the mat surface of the copper foil. It is a thing. The difference from Example 1 is that chloride ions are not added in the foil-making process. When chloride ions are not added to the electrolytic solution in the foil-making process, Rz is in the range of 2.0 μm to 6.0 μm, but Rz / S is smaller than 2.0, and sufficient adhesion strength is obtained. Absent. The adhesion strength between the copper foil and the adhesive was 0.35 kN / m.

(Comparative Example 4)
In Comparative Example 4, the current density in the foil making process was 110 A / dm ² . The other production conditions are the same as in Example 6. When the current density in the foil-making process is higher than 90 A / dm ² , the mat surface uneven shape is changed, and Rz becomes larger and S becomes smaller than the example using the current density of 40 to 80 A / dm ² . As a result, Rz was in the range of 2.0 to 6.0 μm, but Rz / S was larger than 6.0. In this case, as in Comparative Example 1, bubbles were observed at the interface between the copper foil and the adhesive. The adhesion strength between the copper foil and the adhesive was 0.41 kN / m.

(Comparative Example 5)
In Comparative Example 5, the resin that is bonded to the copper foil via an adhesive is a polyimide resin, and the other methods for manufacturing the copper foil are the same as in Comparative Example 2. Rz is smaller than 2.0 μm and Rz / S is smaller than 2.0. The adhesion strength between the copper foil and the adhesive was higher than when a PET film was used, and was 0.40 kN / m.

  As shown above, Examples 1 to 11 have adhesive adhesive strengths of 0.45 to 0.72 kN / m, while Comparative Examples 1 to 5 are 0.20 to 0.41 kN / m. It was confirmed that the present invention is effective in improving the adhesiveness of the adhesive.

Claims (28)

  In at least one surface, the ten-point average roughness Rz is 2.0 μm or more and 6.0 μm or less, and the ratio (Rz / S) of this to the average distance S between the local peaks is 2.0 or more and 6.0. Metal foil that is:   2. The metal foil according to claim 1, wherein a ratio (Rz / S) of the ten-point average roughness Rz to an average interval S between local peaks is 2.2 or more.   2. The metal foil according to claim 1, wherein a ratio (Rz / S) of the ten-point average roughness Rz to an average interval S between local peaks is 3.5 or more.   The metal foil as described in any one of Claims 1-3 whose ratio (Rz / S) of the said 10-point average roughness Rz and the average space | interval S of a local peak is 5.5 or less.   The metal foil according to any one of claims 1 to 4, wherein the metal foil is a copper foil.   The metal foil according to any one of claims 1 to 5, wherein an average interval S between the local peaks is not less than 0.5 µm and not more than 3.0 µm.   The metal foil according to any one of claims 1 to 6, wherein a ratio (Rz / Sm) of the ten-point average roughness Rz to the average interval Sm of the irregularities is 0.5 or more and 4.0 or less.   The metal foil according to any one of claims 1 to 7, wherein an average interval Sm of the unevenness is 1.0 µm or more and 4.0 µm or less.   On at least one surface, a coating layer made of a Cu—Zn alloy, a coating layer made of a Cu—Ni alloy, a coating layer made of a Co—Ni alloy, a coating layer made of a Ni—Zn alloy, and a rust prevention made of Cr oxide The metal foil as described in any one of Claims 1-8 in which any one or several surface coating layers are formed among the coating layers.   The metal foil according to claim 9, wherein a silane coupling agent treatment layer is formed on the surface coating layer.   The metal foil according to any one of claims 1 to 10, wherein the metal foil is an electrolytic copper foil.   The laminated board which bonded together the metal foil and resin as described in any one of Claims 1-11 via the adhesive agent.   The laminate according to claim 12, wherein the resin is a plastic film. The wiring board in which the circuit which uses the metal foil of the laminated board of Claim 12 or 13 as a material is formed. Solar cell back surface protective sheet for the material of the laminate according to claim 12 or 13. The manufacturing method of a solar cell back surface protection sheet including processing the laminated board of Claim 12 or 13. The solar cell back surface wiring sheet which uses the laminated board of Claim 12 or 13 as a material. The manufacturing method of a solar cell back surface wiring sheet including processing the laminated board of Claim 12 or 13.   The laminated body of metal foil and resin as described in any one of Claims 1-11. The printed wiring board which has a circuit made from the metal foil as described in any one of Claims 1-11. The manufacturing method of the printed wiring board using the metal foil as described in any one of Claims 1-11. The heat dissipation material which has a metal foil as described in any one of Claims 1-11. The manufacturing method of the thermal radiation material using the metal foil as described in any one of Claims 1-11. The heat dissipation material made from the metal foil as described in any one of Claims 1-11. Electrolytic solution containing copper and sulfuric acid in a total of 0.01 to 2.0 mg of chloride ions 20 to 100 mg / L, gelatin 0.2 to 6.0 mg / L, and at least one of thiourea and active sulfur-containing substances / L is added, The copper foil manufacturing method including the process of electrodepositing copper on the conditions of 10-90 A / dm < ² > current density and the linear flow rate of electrolyte solution 1.0-5.0 m / sec. Electrolytic solution containing copper and sulfuric acid in a total of 0.01 to 2.0 mg of chloride ions 20 to 100 mg / L, gelatin 0.2 to 6.0 mg / L, and at least one of thiourea and active sulfur-containing substances / L, and a foil forming step of obtaining an untreated copper foil by electrodepositing copper under conditions of a current density of 10 to 90 A / dm ² and a linear flow rate of the electrolytic solution of 1.0 to 5.0 m / second; A coating layer made of Cu—Zn alloy, a coating layer made of Cu—Ni alloy, a coating layer made of Co—Ni alloy, a coating layer made of Ni—Zn alloy, and a Cr oxide on at least one surface of the untreated copper foil A method for producing a copper foil comprising a surface treatment step of forming a silane coupling agent layer on the surface coating layer after forming any one or a plurality of surface coating layers of the rust-proof coating layer. Electrolytic solution containing copper and sulfuric acid in a total of 0.01 to 2.0 mg of chloride ions 20 to 100 mg / L, gelatin 0.2 to 6.0 mg / L, and at least one of thiourea and active sulfur-containing substances / L, and a foil forming step of obtaining an untreated copper foil by electrodepositing copper under conditions of a current density of 10 to 90 A / dm ² and a linear flow rate of the electrolytic solution of 1.0 to 5.0 m / second; After performing a roughening treatment on at least one surface of the untreated copper foil, a coating layer made of a Cu—Zn alloy, a coating layer made of a Cu—Ni alloy, a coating layer made of a Co—Ni alloy, and a Ni—Zn alloy A copper including a surface treatment step of forming any one or a plurality of surface coating layers of a coating layer made of Cr and a rust-proof coating layer made of Cr oxide, and then forming a silane coupling agent layer on the surface coating layer Foil manufacturing method. Method for manufacturing a laminated board, including the claims 25-27 or the step of bonding with an adhesive a copper foil and a resin produced by the production method according.