KR102095619B1 - Metal foil - Google Patents

Abstract

It provides a metal foil with excellent adhesion to the adhesive. The metal foil whose 10-point average roughness Rz is 2.0 micrometers or more and 6.0 micrometers or less, and the ratio (Rz / S) of the average distance S of this and local calculation is 2.0 or more and 6.0 or less in at least one surface.

Description

Metal foil {METAL FOIL}

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

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

Moreover, as disclosed in, for example, Patent Document 2 (Japanese Patent Application Laid-Open No. 2011-061151), copper foil in the solar cell back surface protection sheet is patterned into a circuit, and the pattern portion and the terminal portion formed on the back side of the solar cell By connecting, a solar cell backside wiring sheet that also functions as a wiring material has been developed.

On the other hand, copper foil has conventionally been mainly used as a circuit material of a printed wiring board. It is common to manufacture the copper foil and a thermosetting insulating resin by thermocompression bonding at a temperature higher than the glass transition temperature of the resin to form a copper-clad laminate, followed by a process of forming a conductor pattern on the copper foil surface by etching. As a technique for improving the adhesion between the copper foil and the thermosetting insulating resin, it is generally practiced to perform surface treatment to form irregularities on the surface of the copper foil called roughening treatment. For example, by using copper sulfate acid plating bath on the rough surface (precipitation surface) of the electrolytic copper foil, a large number of copper particles are electrodeposited in the shape of a tree branch or a small spherical shape to form fine irregularities, and also by a seedling effect (also called an anchor effect). There are ways to improve adhesion. After the roughening treatment, in order to further improve the adhesion strength, the formation of a Cr oxide film by chromate treatment or surface treatment with a silane coupling agent is generally performed.

In a conventional copper foil for a printed wiring board, there are many techniques aimed at improving the adhesion between the copper foil and the resin by paying attention to the surface roughness, and the index indicating the surface roughness of the copper foil is a 10-point average roughness defined in the prior art, JIS B0601-1994. With Rz, a number of techniques have been proposed to obtain adhesion to the resin by controlling Rz of the adhesive surface with the thermosetting resin. For example, Patent Document 3 (Japanese Laid-Open Patent Publication No. 2005-48269) is applicable.

However, when considering the nature of adhesion by the anchoring effect, it is most important to optimize the surface area of the copper foil for the target adhesive. In this regard, in order to discuss the adhesion between the copper foil and the adhesive, it is not enough to control Rz indicating the height of the surface irregularities of the copper foil, and it is necessary to consider the intervals between the irregularities. Generally, the larger the difference in height of the irregularities, that is, the larger the Rz, and the smaller the interval between the irregularities, the larger the surface area. As an index indicating the spacing of the unevenness, representatively, there are the average spacing Sm of the unevenness defined in JIS B0601-1994 and the average spacing S of the local calculation.

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

Japanese Patent Application Publication No. 2009-170771 Japanese Patent Application Publication No. 2011-061151 Japanese Patent Application Publication No. 2005-48269 Japanese Patent Publication No. 2011-216598 Japanese Patent Application Publication No. 2011-219790

As described above, optimization of the surface roughness has been sought for the copper foil for a printed wiring board in order to improve adhesiveness with a resin. However, when laminating a roughened copper foil conventionally used for a printed wiring board with a resin via an adhesive, not only sufficient adhesion between the copper foil and the adhesive is not obtained, but also the laminated sheet is placed under high temperature and high humidity conditions for a long time. There has been a problem that the adhesiveness of the paper is significantly reduced. In addition, there is a problem that the thickness of the adhesive is unnecessarily thickened, which is uneconomical.

As a cause of such a problem, it is conceivable that the surface of the copper foil having fine irregularities and the adhesive are not in close contact in a sufficient contact area. Patent Document 4 (Japanese Patent Application Publication No. 2005-48269) controls Sm in addition to Rz, but controlling Sm in addition to Rz cannot be said to have fully explained the nature of adhesion between copper foil, adhesive, and resin. This is because Sm is only an average value of the mountain valley period of the unevenness, and the existence of a number of fine irregularities existing in the period is not considered.

This is understood by FIG. 1. 1 (a) and (b) are schematic diagrams of the surface roughness curve having the same Sm, but in (b), finer irregularities exist during the valley period of the irregularities. Since (b) has a larger surface area than (a), it can be easily seen that a larger seedling effect can be obtained. An index of the surface roughness indicating the interval of each minute irregularity is the average interval S of the above-mentioned local calculation. S is an average of the peak intervals of the individual acids of the surface roughness curve schematically shown in Fig. 1C. Therefore, it is more important to properly 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 the ranges of Rz and S are specified, and copper foil harmonized particles measured using a violet laser having a wavelength of 408 nm. Of S is controlled to 210 nm or less. In addition, since the spacing of the roughening particles is dense, there are many roughening particles per unit area, and therefore, since the surface area of adhesion to the resin substrate increases and an efficient seedling effect is obtained, it is described that S is smaller, which is preferable. However, Patent Document 5 does not discuss the adhesiveness between the copper foil interposed with the adhesive and the resin, but the range of Rz and S of the copper foil described in the document is excessively small when considering adhesiveness with the adhesive, and S is too small. The present inventor has found a problem that adhesion is not obtained.

The present invention was created in view of the above circumstances, and an object of the present invention is to provide a metal foil having excellent adhesion to an adhesive. Another object of the present invention is to provide a laminate of the above-mentioned metal foil and resin having high adhesion, which is adhered via an adhesive. In addition, another object of the present invention is to provide a solar cell back protection sheet or a solar cell back wiring sheet provided with the laminate.

As a result of earnest research, the present inventor has a 10-point average roughness Rz on the adhesive surface with an adhesive within a range of 2.0 µm or more and 6.0 µm or less, and a ratio (Rz / S) with the average spacing S of local calculations It was found that the metal foil in the range of 2.0 or more and 6.0 or less had excellent adhesiveness with the adhesive.

The present invention has been completed based on the above findings, and in one aspect, in at least one plane, the 10-point average roughness Rz is 2.0 µm or more and 6.0 µm or less, and the ratio of this to the average distance S of the local calculation ( Rz / S) is a metal foil 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 of the local calculation is 0.5 µm or more and 3.0 µm or less.

In another embodiment of the metal foil according to the present invention, the ratio (Rz / Sm) of the 10-point average roughness Rz to the average spacing Sm of irregularities 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 spacing Sm of irregularities is 1.0 µm or more and 4.0 µm or less.

In still another embodiment of the metal foil according to the present invention, in 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, and a Ni-Zn alloy Either one or a plurality of surface coating layers are formed of a coating layer made of, or an 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 another embodiment of the metal foil according to the present invention, the metal foil is an electrolytic copper foil.

This invention is another one side. WHEREIN: It is a laminated board which bonded the metal foil and resin which concerns on this invention via the adhesive agent.

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

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

This invention is another one side. WHEREIN: It is a solar cell back surface protection sheet or solar cell back surface wiring sheet obtained by processing the laminated board which concerns on this invention.

In another aspect, the present invention is a total of at least one of chloride ion 20 to 100 mg / L, gelatin 0.2 to 6.0 mg / L, and thiourea and active sulfur-containing substance in an electrolyte solution containing copper and sulfuric acid. It is the manufacturing method of copper foil containing the process of adding 0.01-2.0 mg / L and electrodepositing copper on conditions with a current density of 10-90 A / dm2.

In another aspect, the present invention is a total of at least one of chloride ion 20 to 100 mg / L, gelatin 0.2 to 6.0 mg / L, and thiourea and active sulfur-containing substance in an electrolyte solution containing copper and sulfuric acid. Cu-Zn on at least one surface of the unprocessed copper foil, and a pulverizing process to obtain untreated copper foil by adding 0.01 to 2.0 mg / L and depositing copper under conditions of a current density of 10 to 90 A / dm 2. After forming any one or a plurality of surface coating layers of a coating layer made of an 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 an antirust coating layer made of Cr oxide, the surface is formed. It is a manufacturing method of copper foil including the surface treatment process of forming a silane coupling agent layer on a coating layer.

In another aspect, the present invention is a total of at least one of chloride ion 20 to 100 mg / L, gelatin 0.2 to 6.0 mg / L, and thiourea and active sulfur-containing substance in an electrolyte solution containing copper and sulfuric acid. After the addition of 0.01 to 2.0 mg / L, electrodepositing copper under the conditions of a current density of 10 to 90 A / dm 2 to obtain an untreated copper foil, and after the roughening treatment is performed on at least one surface of the untreated copper foil, Cu- A coating layer made of a 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 an anti-corrosive coating layer made of Cr oxide are formed to form one or more surface coating layers. It is a manufacturing method of copper foil including the surface treatment process of forming a silane coupling agent layer on a surface coating layer.

This invention is another one side. WHEREIN: It is a manufacturing method of the laminated board containing the process of bonding the copper foil and resin manufactured by the manufacturing method of the copper foil which concerns on this invention through an adhesive agent.

Since the metal foil according to the present invention has high adhesiveness with an adhesive, it exhibits excellent adhesiveness when bonded to a resin via an adhesive. Therefore, the laminated body of the metal foil and resin which concerns on this invention can be used suitably, for example as a solar cell back surface protection sheet and a solar cell back surface wiring sheet.

1 is a schematic view for explaining the difference between the average spacing Sm of irregularities and the average spacing S of local calculations.

The metal foil used in the present invention is not particularly limited, but typically copper foil can be used. However, it goes without saying that if the ratio of Rz and Rz to S (Rz / S) is within the range indicated in the present invention, a metal foil other than copper foil can be used. For example, nickel foil or aluminum foil can be used. Moreover, an alloy foil can also be used.

Copper foil is largely divided into an electrolytic copper foil and a rolled copper foil according to the difference in the manufacturing method. Both are often used as circuit materials for printed wiring boards. In general, electrolytic copper foil is produced by electrolytically depositing copper on a rotating drum made of titanium or stainless steel from a copper sulfate plating bath in a baking process. At this time, it is common to refer to the surface of the rotating drum side as a shiny surface (or drum surface), and the surface contacting the opposite side of the electrolytic solution as a mat surface (or precipitation surface, rough surface). Thereafter, in order to improve the adhesion strength with the resin, in the surface treatment step, roughening treatment, rust prevention treatment, and silane coupling agent treatment are generally performed on either or both surfaces.

Rolled copper foil is produced by repeating plastic working and heat treatment by a rolling roll (rolling process). Subsequently, roughening treatment, rust prevention treatment, and silane coupling agent treatment are generally performed in the surface treatment step as in the case of electrolytic copper foil.

As the composition of the copper foil, in addition to copper of high purity such as electrolytic copper, electroless copper, tough pitch copper or oxygen free copper, which are commonly used as a conductor pattern of a printed wiring board, for example, Sn-containing copper, Ag-containing copper, Cr, Zr or Mg, etc. are added. A copper alloy such as a copper alloy to which one copper alloy, Ni, Si, etc. is added can also be used. In addition, in this specification, when the term "copper foil" is used independently, it shall also include the copper alloy foil.

The thickness of the copper foil that can be used in the present invention is also not particularly limited, and may be appropriately adjusted to a thickness suitable for practical use. 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.

One of the features of the metal foil according to the present invention is that the Rz of at least one surface is 2.0 µm or more and 6.0 µm or less, and the ratio (Rz / S) of Rz and S is 2.0 or more and 6.0 or less. In the present invention, Rz represents the 10-point average roughness specified in JIS B0601-1994, and S represents the average interval S of local calculations specified in JIS B0601-1994.

When Rz is larger than 6.0 µm, the adhesive does not enter the curved portion of the surface irregularities of the copper foil, and the adhesion strength may decrease. In addition, since it is necessary to fill more adhesives in the uneven portions, there is also a problem that the application amount of the adhesive to be used is unnecessarily increased and uneconomical. Therefore, Rz was defined as 6.0 µm or less. Rz is preferably 5.5 μm or less.

Even when Rz is smaller than 2.0 µm, adhesion strength with sufficient adhesive is not obtained. This is because, due to the small contact area between the metal foil and the adhesive, adhesion by the anchoring effect (anchor effect) is not sufficiently obtained. Therefore, Rz was defined as 2.0 µm or more. Rz is preferably 2.5 μm or more, and 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 and S (Rz / S). Rz / S tends to be higher than 6.0 for copper foils that have been used in conventional printed wiring board applications. This means that the uneven spacing in the horizontal direction of the surface is too small for the height of the unevenness. Even in this case, the adhesive does not enter the concave-convex portion, so that sufficient adhesion strength is not obtained. Therefore, in the present invention, the ratio (Rz / S) of the local calculated average spacing S, which is an index indicating the horizontal spacing of the irregularities, was defined as 6.0 or less. Rz / S is preferably 5.5 or less.

In addition, in a low-profile copper foil used for a printed wiring board application with a particularly narrow circuit width or a double-sided smoothing foil for a lithium ion battery negative electrode current collector, Rz / S tends to be less than 2.0, and in this case, the adhesive strength with the adhesive is also low. This is because, because the height of the unevenness is too small compared to the interval of the unevenness, adhesion due to the anchoring effect (anchor effect) is not sufficiently obtained. Therefore, in the present invention, the ratio (Rz / S) to the local calculated average spacing S, which is an index indicating the horizontal spacing of the irregularities, was defined as 2.0 or more. Rz / S is preferably 2.2 or more, and more preferably 3.5 or more.

Moreover, about the local estimated average interval S itself, although it is indirectly prescribed | regulated by defining Rz and Rz / S, since S is too small, since an adhesive agent cannot enter into an uneven | corrugated part, it is preferable that S is 0.5 micrometer or more, and that it is 1.0 micrometer or more. It is more preferable. The upper limit of S is also defined indirectly by defining Rz and Rz / S in the same manner, but is preferably 3.0 µm or less, and more preferably 2.5 µm or less. If S is larger than this range, the adhesive strength with the adhesive is lowered.

In increasing the adhesion strength between the metal foil and the adhesive, the ratio (Rz / Sm) of the 10-point average roughness Rz to the average spacing Sm of irregularities is preferably 0.5 or more and 4.0 or less, and more preferably 1.0 or more and 2.0 or less. Moreover, it is preferable that the mean spacing Sm of unevenness is 1.0 micrometer or more and 4.0 micrometers or less, and it is more preferable that it is 2.0 micrometers or more and 3.5 micrometers or less. However, as premised, sufficient adhesion strength cannot be obtained only by defining these, and it is necessary to adjust both of Rz and Rz / S to an appropriate range. Sm represents the average interval of irregularities specified in JIS B0601-1994.

As a method for producing a metal foil having an optimum range of Rz and Rz / S of the present invention, it is considered that various roughening treatments are performed on the surface of a metal foil made of Cu, Ni, Fe, Al, or the like obtained by electrolysis or rolling. You can. Specifically as the roughening treatment, roughening treatment by electrodeposition of fine particles, chemical etching with a chemical agent, and anodization can be used.

In particular, in order to manufacture the copper foil having the optimum range of Rz and Rz / S of the present invention, it is preferable to optimize the manufacturing conditions of the foil-making process. Specifically, it is preferable to add various additives to the electrolytic solution of copper sulfate, and to perform the slicing under predetermined electrolytic conditions. As an additive, gelatin as a representative example of 0.2 to 6.0 mg / L, preferably 2.0 to 5.5 mg / L, and chloride ion of 20 to 100 mg / L, preferably 20 to 60 mg / L Use in the concentration range. In addition to this, by adding the total concentration of at least one kind of thiourea and active sulfur-containing substance as 0.01 to 2.0 mg / L, preferably 0.1 to 1.5 mg / L, the 10 point average roughness Rz and the local estimated average interval S are added. It can be adjusted to the optimum range. As electrolytic conditions, the liquid temperature is 40 to 70 ° C, preferably 50 to 65 ° C, current density 10 to 90 A / dm2, preferably 50 to 90 A / dm2, and the linear flow rate of the electrolyte is 1.0 to 5.0 m It is preferable to carry out in the range of / sec, preferably 3.0 to 5.0 m / sec.

The concentration of sulfuric acid in the electrolytic solution is not limited, but in order to increase the conductivity of the electrolytic solution and lower the electrolytic voltage, to reduce power consumption, it is preferably 50 to 150 g / L, and more preferably 80 to 120 g / L. Do.

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 to improve productivity during commercial production.

The surface of the metal foil according to the present invention may further be subjected to various heat-resistant and anti-rust surface treatments or silane coupling agent treatments for the purpose of preventing oxidation discoloration of the metal foil and improving adhesion strength with an adhesive. For example, in one embodiment of the metal foil according to the present invention, at least a Cu-Zn alloy, a Cu-Ni alloy, a Ni-Co alloy, a Ni-Zn alloy, Cr on a surface that satisfies the above-mentioned surface roughness regulation Any one or a plurality of coating treatment layers made of oxide may be combined and stacked. 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 Cr oxide is formed thereon. In the case of laminating a coating treatment layer made of a Cu-Zn alloy, a coating treatment layer made of a Ni-Zn alloy and a coating treatment layer made of a Cr oxide are sequentially stacked thereon. The case where a coating treatment layer made of a Zn alloy is formed and a coating treatment layer made of Cr oxide is formed thereon is mentioned.

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

In another embodiment of the copper foil according to the present invention, surface coating with a silane coupling agent may be applied to the coating treatment layer. The surface coating layer with a silane coupling agent is effective because it cross-links the surface of the metal (copper foil) and the surface of the organic material (adhesive) to improve the adhesion to each other.

Since the silane coupling agent layer usually has a thickness of several to several tens of atoms, and is very thin, the values of Rz and Rz / S of the copper foil are not significantly changed.

The metal foil according to the present invention exhibits excellent adhesion to an adhesive by having the above-mentioned specific surface roughness. Although it is not limited to the adhesive used for lamination of the metal foil and the resin, the effect is high for, for example, an epoxy resin adhesive, a urethane resin adhesive, and a polyester resin adhesive. Although it can be used for a polyimide-based adhesive, the polyimide-based adhesive has a high adhesive strength even in a conventional copper foil, so that the excellent adhesive strength of the present invention is significantly exhibited with adhesives other than polyimide-based adhesives. It is time for bonding.

The metal foil which concerns on this invention can form a laminated board by bonding with resin through an adhesive agent. Copper foil can also be used as a metal foil to heat-press the resin, particularly an insulating thermosetting resin, to form a copper-clad laminate. The material of the resin is not limited, for example, fluorine-containing resins such as polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinyl acetate resin, polyethylene terephthalate ( PET), polybutylene terephthalate (PBT), polyester resins such as polyethylene naphthalate (PEN), polyolefin resins such as polypropylene, polyethylene, polyphenylene sulfide (PPS), and the like can be appropriately selected and used. The insulating thermosetting resin is not limited, and examples thereof include an epoxy resin and a bismaleimide-triazine resin. Naturally, it can also be combined with polyimide.

The thickness of the resin is not particularly limited, and may be appropriately changed depending on the application. The thickness of the plastic film may be flexible, for example, 10 to 1000 μm.

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

Example

Below, examples of the present invention are shown. These are provided to better understand the present invention, and are not intended to limit the present invention to the examples described below.

(Filing process)

Electrolysis was performed on the columnar cathode made of stainless steel under the electrolytic solution and electrolytic conditions as shown below to obtain a copper foil having a predetermined thickness. In all the 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 baking process)

Cu (as ^{Cu 2 +): 100 g /} ℓ

H ₂ SO ₄ ： 100 g / ℓ

Cl (as chloride ion), glue, and thiourea were added as additives in the respective amounts shown in Table 1.

(Electrolysis conditions of the baking process)

Liquid temperature: 57 ℃

Current density: 40 to 80 A / d㎡

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 copper foil. The Rz of the surface to be bonded with the adhesive was measured by a surf coder SE-3C manufactured by Kosaka Research Institute, and was 1.0 µm before surface treatment.

(Harmonic processing)

In Examples 6-8 and 11, the roughening process of two steps shown below was given to the mat surface of the copper foil obtained by the baking process and the surface of an aluminum foil.

(1 step of harmonization)

The purpose of the first stage roughening treatment is to generate nuclei of the roughening particles on the surface of the metal foil by electrodeposition of Cu fine particles at a current density exceeding the limiting current density of copper ion diffusion to the outermost surface of the metal foil.

(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

(Conditions for harmonization)

Liquid temperature: 20 to 50 ℃

Current density: 20 to 100 A / d㎡

Power-on time: 1 to 10 seconds

(Two-level harmonization)

The purpose of the roughening treatment in the second stage is to grow the roughening particle nuclei by smooth plating on the nuclei of the roughening particles produced in the roughening treatment in the first stage to obtain roughened particles of a predetermined size.

(Electrolytic solution composition)

Cu (as ^{Cu 2 +): 20 ~ 60} g / ℓ

H ₂ SO ₄ : 50 to 150 g / ℓ

(Conditions for harmonization)

Liquid temperature: 30 to 60 ℃

Current density: 1 to 50 A / d㎡

Power-on time: 1 to 10 seconds

(Surface treatment process)

In Examples 1-8 and 10-11, the surface coating treatment (a) shown below on one side of the mat surface (roughness, precipitation surface) or aluminum foil (Example 11) of the copper foil obtained in the baking process, ( b), (c), (d), or (e) any one or a plurality of treatment was selected. Table 1 shows the combination 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 acid, and then measuring the concentration of the element of the coating treatment layer component in the solution by the ICP-AES method.

(a) Cu-Zn alloy plating treatment

(Electrolyte composition, pH)

NaCN: 10-30 g / ℓ

NaOH: 40 ∼ 100 g / ℓ

Cu (CN) ₂ : 60 to 120 g / ℓ

Zn (CN) ₂ : 1 to 10 g / ℓ

pH: 10-13

(Electrolytic conditions)

Liquid temperature: 50 to 80 ℃

Current density: 10 A / d㎡

Plating time: 4 seconds

Coating amount: 5.0 mg / d㎡

(b) Ni-Zn alloy plating treatment

(Electrolyte composition, pH)

Zn (Zn ⁺ a ^2): 12 ~ 25 g / ℓ

Ni (Ni as ^{2 +): 1 ~ 8 g} / ℓ

pH: 2.0-4.0

(Electrolytic conditions)

Liquid temperature: 25 to 50 ℃

Current density: 10 A / d㎡

Plating time: 2 seconds

Coverage: 1.5 mg / d㎡

(c) Cu-Ni alloy plating treatment

(Electrolyte composition, pH)

Cu (as ^{Cu 2 +): 0.01 ~ 5.0} g / ℓ

Ni (Ni as ^{2 +): 5 ~ 25 g} / ℓ

pH: 2.0-4.0

(Electrolytic conditions)

Liquid temperature: 25 to 50 ℃

Current density: 5 A / d㎡

Plating time: 2 seconds

Coverage: 1.0 mg / d㎡

(d) Co-Ni alloy plating treatment

(Electrolyte composition, pH)

Co (as ^{Co 2 +): 0.1 ~ 6.0} g / ℓ

Ni (Ni as ^{2 +): 5 ~ 20 g} / ℓ

pH: 2.0-4.0

(Electrolytic conditions)

Liquid temperature: 25 to 50 ℃

Current density: 5 A / d㎡

Plating time: 3 seconds

Coverage: 3.0 mg / d㎡

(e) Electrolytic chromate treatment

(Electrolyte composition, pH)

K ₂ Cr ₂ O ₇ ： 2.0 ∼ 6.0 g / ℓ

Zn (as Zn ^{2 +} ): 0 to 0.5 g / ℓ

Na ₂ SO ₄ ： 5 ∼ 15 g / ℓ

pH: 3.5 to 5.0

(Electrolytic conditions)

Liquid temperature: 20 to 60 ℃

Current density: 2.0 A / d㎡

Plating time: 2 seconds

Coating amount: 0.15 mg / d㎡

Finally, the silane coupling agent treatment shown below was performed on the coating treatment layer.

Silane coupling agent treatment

After spray application of a 0.2 vol% solution of 3-glycidoxypropyltriethoxysilane, it was dried in air at a temperature of 100 ° C. or higher for 1 to 10 seconds.

(Measurement of surface roughness)

The 10-point average roughness Rz of the mat surface of the metal foil thus produced, the average distance S of local calculation, and the average distance Sm of unevenness were measured. The 10-point average roughness Rz was measured by Surf Coder SE-3C manufactured by Kosaka Research Institute. The average distance S of local calculation and the mean distance Sm of irregularities were measured using VK-8510 manufactured by Keyence Co., Ltd. As a measurement method, a line roughness-JIS94 mode was used. Table 1 shows the measurement results.

(Production of laminated sheets)

In addition, in order to measure the adhesive strength of the produced metal foil and adhesive, a laminated sheet of a metal foil and a plastic film was produced in the following procedure.

(Plastic film)

In Examples 1 to 9 and 11 and Comparative Examples 1 to 4, as a film made of polyethylene terephthalate (PET), Toray Co., Ltd. Lumirror (thickness: 200 µm) was used.

(glue)

The adhesive was used by mixing Toyo Morton Co., Ltd .: 2-liquid mixed adhesive (Topic: polyester-based polyol AD-76P1) / (curing agent TCS-4277) and ethyl acetate. The mixing ratio (volume standard) was set to AD-76P1: TCS-4277: ethyl acetate = 7.5: 1.0: 6.5.

(Adhesive application)

On the PET film, the adhesive was uniformly applied to 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.

(Laminate method)

The surface-coated surface of the metal foil and the adhesive-coated surface of the PET film were compressed using a rubber roller to form a laminated sheet of the metal foil and the PET film.

(Thermal curing 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 was used as a resin and an adhesive constituting the laminate, and the lamination sheet was produced by heat pressing with a heat press at a temperature of 240 ° C. and a pressure of 2.5 Mpa.

(Wiring sheet production)

The metal foil on the produced laminated sheet was etched using an iron chloride-hydrochloric acid-based etching solution to obtain a circuit wiring sheet. The circuit width was set to 10 mm for the adhesive strength measurement described below.

(Measurement of adhesion strength)

The adhesion strength of the metal foil and the adhesive was measured using the 90 degree peel strength method specified in JIS-C6481. For the measurement, an autograph AGS-J manufactured by Shimadzu Corporation was used. Table 1 shows the measurement results.

(Examples 1 to 11)

In Examples 1-11, the 10-point average roughness was 2.6-5.6 micrometers, the local estimated average interval S was 1.0-1.3 micrometers, and the Rz / S ratio became the range of 2.2-5.5. The adhesive strength of the copper foil and the aluminum foil and the adhesive is 0.45 to 0.72 kN / m, and has sufficient adhesive strength.

(Comparative Example 1)

In Comparative Example 1, after smelting without the addition of thiourea in the electrolytic solution of the slicing step, roughening treatment, Cu-Zn alloy plating treatment, chromate treatment, and silane coupling agent treatment were sequentially performed on the mat surface of the copper foil. The difference from Example 1 is that the thiourea is not added in the slicing process and the roughening treatment is performed. Since thiourea is not added to the electrolytic solution of the film forming step, 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. In addition, many bubbles were present at the interface between the copper foil and the adhesive.

(Comparative Example 2)

In Comparative Example 2, after the foil was added without adding glue in the electrolytic solution of the film forming step, Ni-Zn alloy plating treatment, chromate treatment, and silane coupling agent treatment were sequentially performed on the mat surface of the copper foil. The difference from Example 5 is that no glue was added in the bakery process. When glue was not added to the electrolytic solution in the film forming step, 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 copper foil was added without adding chloride ions to the electrolytic solution of the film forming step, Cu-Zn alloy plating treatment, chromate treatment, and silane coupling agent treatment were sequentially performed on the mat surface of the copper foil. The difference from Example 1 is that chloride ions are not added in the baking process. When chloride ions are not added to the electrolytic solution in the film forming step, Rz is in the range of 2.0 µm or more and 6.0 µm or less, but Rz / S is smaller than 2.0, and sufficient adhesion strength is not obtained. 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 film-forming step was 110 A / dm 2. Other manufacturing conditions were the same as in Example 6. When the current density in the forming step is higher than 90 A / dm 2, the surface shape of the mat surface is changed, and Rz is larger and S is smaller than the examples using the current densities of 40 to 80 A / dm 2. As a result, Rz is in the range of 2.0 to 6.0 µm, but Rz / S is larger than 6.0. In this case also, in the same manner as in Comparative Example 1, air 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, a resin to be adhered via a copper foil and an adhesive was used as a polyimide resin, and the other methods of manufacturing the copper foil were 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 the PET film was used, and it 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, and the present invention is effective in improving adhesiveness of the adhesive. It was confirmed that there is.

Claims (26)

In at least one surface, the average point roughness Rz of 10 points is 2.0 µm or more and 6.0 µm or less, and the ratio (Rz / S) of the average spacing S of this and the local calculation is 2.0 or more and 6.0 or less, and the average spacing Sm of irregularities Metal foil for laminated body with resin which is 1.0 micrometer or more and 4.0 micrometers or less. According to claim 1,
The metal foil whose ratio (Rz / S) of the said 10-point average roughness Rz and the average distance S of a local calculation is 2.2 or more and 6.0 or less. According to claim 1,
The metal foil whose ratio (Rz / S) of the said 10-point average roughness Rz and the average distance S of a local calculation is 3.5 or more and 6.0 or less. According to claim 1,
The metal foil whose ratio (Rz / S) of the said 10-point average roughness Rz and the average distance S of a local calculation is 2.0 or more and 5.5 or less. According to claim 1,
Metal foil with copper foil. According to claim 1,
Metal foil whose average distance S of local calculation is 0.5 micrometer or more and 3.0 micrometers or less. The method according to any one of claims 2 to 5,
Metal foil whose average distance S of local calculation is 0.5 micrometer or more and 3.0 micrometers or less. According to claim 1,
The metal foil whose ratio (Rz / Sm) of 10-point average roughness Rz with respect to the average spacing Sm of irregularities is 0.5 or more and 4.0 or less. The method according to any one of claims 2 to 6,
The metal foil whose ratio (Rz / Sm) of 10-point average roughness Rz with respect to the average spacing Sm of irregularities is 0.5 or more and 4.0 or less. delete delete The method according to any one of claims 1 to 6 and 8,
On at least one surface, any one of 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 an antirust coating layer made of Cr oxide, or Metal foil in which a plurality of surface coating layers are formed. The method of claim 12,
Metal foil in which a silane coupling agent treatment layer is formed on the surface coating layer. According to claim 1,
A metal foil in which the metal foil is an electrolytic copper foil. A laminated sheet in which the metal foil and the resin according to any one of claims 1 to 6, 8 and 14 are pasted together through an adhesive. The method of claim 15,
A laminate in which the resin is a plastic film. A wiring board in which the metal foil of the laminate according to claim 15 is partially etched to form a circuit. A solar cell back surface protective sheet obtained by processing the laminate according to claim 15. The laminated body of the metal foil and resin in any one of Claims 1-6, 8, and 14. A printed wiring board manufactured using the metal foil according to any one of claims 1 to 6, 8 and 14. A heat radiation material produced using the metal foil according to any one of claims 1 to 6, 8 and 14. A method for manufacturing the copper foil according to claim 5,
20 to 100 mg / L of chloride ions, 0.2 to 6.0 mg / L of gelatin, and 0.01 to 2.0 mg / L of a total of at least one of thiourea and active sulfur-containing substances are added to the electrolyte solution containing copper and sulfuric acid, A method for producing copper foil, comprising a step of electrodepositing copper under conditions of a current density of 10 to 90 A / d m 2 and a line flow rate of 1.0 to 5.0 m / sec of the electrolyte. A method for manufacturing the copper foil according to claim 5,
20 to 100 mg / L of chloride ions, 0.2 to 6.0 mg / L of gelatin, and 0.01 to 2.0 mg / L of a total of at least one of thiourea and active sulfur-containing substances are added to the electrolyte solution containing copper and sulfuric acid, A copper foil electrodeposition process to obtain untreated copper foil by electrodeposition of copper at a current density of 10 to 90 A / d m 2 and a linear flow rate of 1.0 to 5.0 m / sec of the electrolyte solution, and a coating layer made of a Cu-Zn alloy on at least one surface of the untreated copper foil , After forming one or a plurality of surface coating layers of 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 an anti-corrosive coating layer made of Cr oxide, silane on the surface coating layer A method of manufacturing a copper foil comprising a surface treatment step of forming a coupling agent layer. A method for manufacturing the copper foil according to claim 5,
20 to 100 mg / L of chloride ions, 0.2 to 6.0 mg / L of gelatin, and 0.01 to 2.0 mg / L of a total of at least one of thiourea and active sulfur-containing substances are added to the electrolyte solution containing copper and sulfuric acid, Cu-after a roughening treatment is performed on a copper foil-depositing process to obtain an untreated copper foil by electrodepositing copper under conditions of a current density of 10 to 90 A / dm2 and a linear flow rate of 1.0 to 5.0 m / sec of the electrolytic solution, and at least one surface of the untreated copper foil. A coating layer made of a 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 an anti-corrosive coating layer made of Cr oxide are formed to form one or more surface coating layers. A method for producing a copper foil comprising a surface treatment step of forming a silane coupling agent layer on the surface coating layer. The manufacturing method of the laminated board containing the process of bonding the copper foil and resin manufactured by the manufacturing method in any one of Claims 22-24 via an adhesive agent. A solar cell backside wiring sheet obtained by processing the laminate according to claim 15.

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