JP2009299157A - Tin plating film and composite material having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an Sn plating film that can give excellent maintenance property of a roll and improve productivity by preventing the Sn plating film from being rubbed or dropped, and to provide a composite material having the plating film. <P>SOLUTION: The Sn plating film 2 is formed on one surface of a copper foil or a copper alloy foil 1 on the other side of which a resin layer or a film 4 is laminated, wherein glossiness of the Sn plating surface ranges from 10 to 80%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an Sn plating film used for an electromagnetic wave shielding material or the like and formed on the other surface of a copper foil or a copper alloy foil laminated with a resin or the like, and a composite material having the same.

The Sn plating film is characterized by excellent corrosion resistance, good solderability and low contact resistance. For this reason, for example, Sn plating is used for metal foils, such as copper, as a composite material of a vehicle-mounted electromagnetic wave shielding material.
As the above composite material, as a composite material such as an electromagnetic shielding material based on copper or copper alloy foil, a resin layer or a film is laminated on one surface of copper foil or copper alloy foil, and Sn is formed on the other surface. A structure in which a plating film is formed is used.

Sn plating on copper or copper alloy foil is usually performed by wet plating, but an additive is added to the plating solution to ensure the stability of the plating film (the color tone is uniform and there are no color spots or patterns). In many cases, bright Sn plating is performed.
For example, Patent Document 1 discloses a technique for performing bright Sn plating by adding a brightener to a plating solution.

Japanese Patent No. 3007207

However, when performing normal bright Sn plating on a metal foil such as copper or copper alloy foil in a continuous line, there is a problem that the Sn plating surface is rubbed and transferred and adhered to the roll. When plating adheres to the surface of the roll, productivity during plating is reduced by cleaning the roll, etc., and when Sn adhesion is extremely severe, the Sn plating film becomes thin, leading to a reduction in the corrosion resistance of the resulting composite material. This is a problem that cannot be ignored because there is a fear.
The reason why such a defect occurs is not clear, but it is considered that the surface of the contact between the roll and the strip (plating surface) is increased because the bright Sn plating has a smooth plating surface.

  Further, since the copper foil is thin, its strength is low, and folding and wrinkling are likely to occur when passing through a continuous line such as Sn plating. Therefore, when using as a shielding material, Sn plating is generally carried out after a resin or film is previously applied to the copper foil. However, even a copper foil with a resin or film attached in this way may be broken or wrinkled when the tension applied to the strip is increased during continuous plating. For this reason, in order to prevent the generation | occurrence | production of a fold and a wrinkle stably, it is necessary to thread with a low tension | tensile_strength. On the other hand, when the tension applied to the strip is lowered, the contact pressure between the roll and the strip is lowered, and the roll is likely to slip. In particular, when the contact area between the roll and the strip is large under a low tension condition, the contact pressure is lowered due to the increase in the contact surface, and therefore slipping is further facilitated. Once the roll and the Sn plating film slip, the Sn plating easily adheres to the roll due to frictional heat, etc., and the Sn plating starts to adhere to the roll when it is continuously plated it is conceivable that.

Moreover, when using the composite material obtained by Sn-plating copper foil for electromagnetic wave shielding materials, such as a cable, a composite material is wound around a cable outer periphery, and also the resin is coat | covered on the outer side. In this resin coating process, when a composite material to which Sn plating is adhered in the Sn plating process as described above is used, when the composite material passes through the die (die), the Sn plating film easily falls off, and the Sn is formed on the die. The possibility that debris will adhere increases. And if Sn residue adheres to the die, time is required for maintenance, and productivity is lowered.
The present invention has been made in order to solve the above-mentioned problems. By preventing the Sn plating film from sliding or falling off at the time of plating or use, it is excellent in roll maintainability and improves productivity. An object of the present invention is to provide a Sn plating film that can be used and a composite material having the same.

  As a result of various studies, the present inventors have succeeded in reducing the sliding and dropping of the Sn plating film by reducing the glossiness of the Sn plating film surface on the surface of the copper or copper alloy foil.

  In order to achieve the above object, the Sn plating film of the present invention is formed on the other surface of a copper foil or copper alloy foil laminated with a resin layer or film, and the Sn plating surface has a gloss Gs (60 °). 10 to 80%.

  The thickness of the Sn plating film is preferably 0.5 μm or more.

  The composite material of the present invention is formed on a copper foil or copper alloy foil, a resin layer or film laminated on one surface of the copper foil or copper alloy foil, and the other surface of the copper foil or copper alloy foil. And the Sn plating film.

The thickness of the composite material is preferably 0.1 mm or less.
In addition, the glossiness Gs (60 °) of the Sn plating in the present invention is a glossiness measured in accordance with “JIS Z 8741, Measurement Method 3 60 ° Specular Gloss”.

  ADVANTAGE OF THE INVENTION According to this invention, the Sn plating film which can be excellent in the maintainability of a roll and can improve productivity by preventing a Sn plating film from sliding and dropping, and a composite material having the same are obtained.

  Embodiments of the present invention will be described below. In the present invention, “%” means “% by mass” unless otherwise specified.

The composite material which concerns on embodiment of this invention is the copper foil (or copper alloy foil) 1, the resin layer (or film) 4 laminated | stacked on one surface of the copper foil (or copper alloy foil) 1, and copper It consists of Sn plating film 2 formed in the other surface of foil (or copper alloy foil) 1.
From the viewpoint of lightening the material, the thickness of the composite material is preferably 0.1 mm or less.

As the copper foil, tough pitch copper having a purity of 99.9% or more, oxygen-free copper, and as the copper alloy foil, a known copper alloy can be used depending on required strength and conductivity. Known copper alloys include, for example, 0.01 to 0.3% tin-containing copper alloys and 0.01 to 0.05% silver-containing copper alloys. -0.12% Sn and Cu-0.02% Ag are often used.
Although the thickness in particular of copper foil (or copper alloy foil) is not restrict | limited, For example, the thing of 5-50 micrometers can be used conveniently.
In addition, as copper foil (or copper alloy foil), it is preferable to use a rolled foil having higher strength than electrolytic foil.
Moreover, the surface roughness of the copper foil (or copper alloy foil) can be 0.3 μm or less, preferably 0.2 μm or less in terms of the center line average roughness, but if the surface roughness is less than 0.1 μm Adhesiveness with the resin layer may be insufficient.

As the resin layer, for example, a resin such as polyimide can be used, and as the film, for example, a film of PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) can be used. The resin layer or film may be bonded to the copper foil (or copper alloy foil) with an adhesive, but the molten resin is cast on the copper foil (copper alloy foil) without using the adhesive, or the film is made of copper. You may make it thermocompression-bond to foil (copper alloy foil).
The thickness of the resin layer or film is not particularly limited, but for example, a thickness of 5 to 50 μm can be suitably used. When an adhesive is used, the thickness of the adhesive layer can be set to 10 μm or less, for example.

The glossiness Gs (60 °) of the Sn plating surface is 10 to 80%. If the gloss level Gs (60 °) of the Sn plating film is 80% or less, the Sn plating surface has moderate irregularities, the contact area between the Sn plating surface and the roll is small, and the contact pressure with the roll is strong. Become. For this reason, slip on the roll is reduced, and Sn plating adheres less easily.
In addition, when the Gs (60 °) of the Sn plating surface is 80% or less, even when the obtained composite material is used as an electromagnetic shielding material such as a cable, the Sn plating film and roll (and dice) are processed at the time of processing the shielding material. The contact area with is reduced. For this reason, Sn adhesion to a roll can be prevented and productivity can be improved. And when the obtained composite material is processed, powder fall of Sn plating film does not arise and adhesiveness does not fall.

On the other hand, in the case of a smooth Sn plating surface in which the glossiness Gs (60 °) of the Sn plating film exceeds 80%, the contact area between the Sn plating surface and the roll is large, and the contact pressure with the roll is low. Become. Therefore, slipping on the roll is likely to occur, and when plating is continuously performed in the slipped state, Sn plating adheres to the roll due to frictional heat or the like.
If a normal plating film is obtained, Gs (60 °) will not be less than 10%. However, for example, in the case of insufficient plating conditions such as extremely short plating time, Sn plating Electrodeposited grains become island-shaped, plating unevenness may occur, and Gs (60 °) may be less than 10%. Therefore, the glossiness of the Sn plating film is 10 to 80%.

The thickness of the Sn plating film is preferably 0.5 μm or more. When the thickness is less than 0.5 μm, the corrosion resistance and solderability may deteriorate.
In addition, the upper limit of the thickness of the Sn plating film is not particularly limited because it varies depending on the manufacturing conditions of Sn plating, etc. However, even if the Sn plating is thickened exceeding 2 μm, no further improvement in corrosion resistance and solderability is observed. On the contrary, there are also negative aspects such as increasing the Sn plating allowance and decreasing the productivity. Therefore, it is preferable that the thickness of the Sn plating film is 0.5 to 2 μm.

  The method for measuring the glossiness of the Sn plating film is as follows. First, it measures based on "JIS Z8741 measuring method 3 60 degree specular gloss" from the Sn plating film surface. Then, using a contact-type gloss meter, 5 points are measured with a measurement size of 10 × 20 mm, and the average value is defined as the gloss level.

As a method of controlling the gloss of the Sn plating film to 10 to 80%, a brightener (for example, a commercially available chemical such as formalin and aldehyde, imidazole, and benzalacetone) is added to the Sn plating bath. And a method of electroplating that does not smooth the surface (matte); a method of adjusting the current density, Sn concentration, and bath temperature, respectively, and enlarging the electrodeposited grains.
Examples of the base for the Sn plating bath that can be used in the present invention include phenolsulfonic acid, sulfuric acid, methanesulfonic acid, and the like. However, a surfactant EN (ethoxylated naphthol) such as naphthol may be added to the Sn plating bath. Further, nonionic surfactants such as ENSA (ethoxylated naphthol sulfonic acid), polyethylene glycol, and polyethylene glycol nonylphenol ether may be added to the Sn plating bath. In addition to the surfactant, an organic substance such as naphthol having a low gloss effect may be added.
Under plating conditions, the current density can be lowered, the Sn concentration can be increased, and the temperature can be increased to increase the electrodeposited grains. For example, when the current density is ^{2 to} 12 A / dm ² , the Sn concentration is 30 to 60 g / L, and the bath temperature is 30 to 60 ° C., the granular electrodeposited Sn can be uniformly electrodeposited on the copper foil surface. The glossiness of the plating film can be made 10 to 80%. However, the plating conditions differ depending on the plating apparatus, and are not particularly limited to the above.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these.

A strip was obtained by bonding a PET film having a thickness of 12.5 μm to one surface of a tough pitch copper foil (thickness: 7.3 μm) of 99.9% or more copper using a thermoplastic adhesive. This strip was electroplated in a continuous plating cell facing the tin anode. A phenol sulfonic acid bath was used as a plating bath, and surfactant EN 10 g / L and tin oxide were added to obtain a Sn concentration of 32 to 40 g / L. The plating conditions were a bath temperature of 45 to 55 ° C., a current density of 8 to 11 A / dm ² , and a plating thickness of 1.5 μm.

The resulting Sn plating film had a glossiness of 38% (see FIG. 3). The gloss was measured with a contact-type gloss meter (PG-1M manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with “JIS Z 8741 Measuring Method 3 60-degree Specular Gloss”. The measurement size was 10 × 20 mm, and five locations were measured, and the average value was taken as the glossiness.
In addition, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was not observed on the roll even when 4700 m was fed.
Further, a salt spray test (Z2371) (temperature: 35 ° C., salt water concentration: 5% (sodium chloride), spray pressure: 98 ± 10 kPa, spray time: 480 h) was performed as an evaluation of corrosion resistance. When the plated surface was visually observed, there was no change in the plated surface (specifically, the copper color of the base material was not seen), and the corrosion resistance evaluation was good.

Continuous plating was performed in exactly the same manner as in Example 1 except that the plating thickness was 0.5 μm.
The resulting Sn plating film had a glossiness Gs (60 °) of 72%.
In addition, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was not observed on the roll even when 4700 m was fed. Moreover, corrosion resistance evaluation was also favorable.

Continuous plating was performed in exactly the same manner as in Example 1 except that the plating thickness was 2.0 μm and the current density was 6 to 8 A / dm ² .
The glossiness Gs (60 °) of the obtained Sn plating film was 35%.
In addition, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was not observed on the roll even when 4700 m was fed. Moreover, corrosion resistance evaluation was also favorable.

Continuous plating was performed in the same manner as in Example 1 except that the plating thickness was 2.0 μm and the current density was 5 to 6 A / dm ² .
The glossiness Gs (60 °) of the obtained Sn plating film was 20%.
In addition, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was not observed on the roll even when 4700 m was fed. Moreover, corrosion resistance evaluation was also favorable.

Continuous plating was performed in exactly the same manner as in Example 1 except that the plating thickness was 0.4 μm.
The glossiness Gs (60 °) of the obtained Sn plating film was 75%, and when the roll on the plating outlet side was observed during continuous plating, no Sn adhesion was observed on the roll even when 4700 m was passed through the foil. .
However, since the plating thickness was as thin as 0.4 μm, when visually observed, corrosion of the plating layer was observed (specifically, the copper color that is the color of the base material was observed on the surface), and the corrosion resistance evaluation was inferior. .

<Comparative Example 1>
Continuous plating was performed in exactly the same manner as in Example 1 except that the plating thickness was 1.0 μm and a brightener (paraaldehyde 12 ml / L, naphthaldehyde 0.2 ml / L) was added to the Sn plating bath.
The glossiness Gs (60 °) of the obtained Sn plating film was 90%. (See FIG. 4).
Further, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was noticeably observed on the roll when 3000 m was passed through. The corrosion resistance evaluation was good.

<Comparative Example 2>
Continuous plating was performed in exactly the same manner as in Example 1 except that the plating thickness was 0.5 μm and the current density was 12 to 15 A / dm ² .
The glossiness Gs (60 °) of the obtained Sn plating film was 85%.
Further, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was noticeably observed on the roll when 3000 m was passed through. The corrosion resistance evaluation was good.

<Comparative Example 3>
Example 1 except that the plating thickness was 1.5 μm, and a brightener (paraaldehyde 12 ml / L, naphthaldehyde 0.2 ml / L) was added to the Sn plating bath to obtain a current density of 12 to 15 A / dm ^2. Continuous plating was performed in exactly the same manner.
The glossiness Gs (60 °) of the electrodeposited grains of the obtained Sn plating film was 108%.
Further, when the roll on the plating outlet side was observed during continuous plating, Sn adhesion was noticeably observed on the roll when 3000 m was passed through. The corrosion resistance evaluation was good.

  The obtained results are shown in Table 1.

As is clear from Table 1, in each Example in which the gloss level Gs (60 °) of the Sn plating film was 10 to 80%, Sn did not adhere to the roll for a long time even by continuous plating.
On the other hand, in the case of Comparative Examples 1 to 3 in which the gloss level Gs (60 °) of the Sn plating film exceeded 80%, Sn adhered to the roll when continuous plating was performed 3000 m.

It is the figure which showed an example of the composite material of this invention. It is a scanning electron microscope image of the magnification of 5000 times from the Sn plating film surface of the example 1 of an invention. 5 is a scanning electron microscope image at a magnification of 5000 times from the Sn plating film surface of Comparative Example 2. FIG.

Explanation of symbols

1 Copper foil (or copper alloy foil)
2 Sn plating film 4 Resin layer (or film)

Claims (4)

  An Sn plating film formed on the other surface of a copper foil or copper alloy foil laminated with a resin layer or film, and having a Sn plating surface glossiness Gs (60 °) of 10 to 80%.   The Sn plating film according to claim 1, wherein the thickness is 0.5 μm or more.   The copper foil or copper alloy foil, the resin layer or film laminated on one surface of the copper foil or copper alloy foil, and the other surface formed on the other surface of the copper foil or copper alloy foil. A composite material comprising the described Sn plating film.   The composite material according to claim 3, wherein the thickness is 0.1 mm or less.