TWI468286B - A copper foil composite, and a molded body and a method for producing the same - Google Patents

Description

Copper foil composite, molded body and method of producing the same

The present invention relates to a copper foil composite in which a copper foil and a resin layer are laminated, and a molded body and a method for producing the same.

A copper foil composite system in which a copper foil and a resin layer are laminated is applied to an FPC (Flexible Printed Circuit Board), an electromagnetic wave mask, an RF-ID (wireless IC tag), a planar heat generating body, and a heat sink. For example, in the case of FPC, a circuit of copper foil is formed on the base resin layer, and a cover film of the protective circuit covers the circuit to form a laminated structure of a resin layer/copper foil/resin layer.

Therefore, the workability of the copper foil composite is required to be a copper foil composite excellent in bending property or bending property, which is characterized by bending property represented by MIT bending property and high cycle bending property represented by IPC bending property. Body (for example, Patent Documents 1 to 3). For example, the FPC can be bent at a movable portion such as a hinge portion of a mobile phone, or bent for a small space of the circuit, but as a deformation mode, it is represented by the MIT bending test or the IPC bending test. The shaft is bent and designed in such a way that it does not become a severe deformation mode.

In addition, when the copper foil composite is used for an electromagnetic wave mask or the like, the resin layer/copper foil has a laminated structure, and the surface of the copper foil composite is required to exhibit corrosion resistance and long-term stable electrical contact performance.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-100887

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-111203

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2007-207812

However, when the copper foil composite is subjected to press working or the like, it is a severe (complex) deformation mode different from the MIT bending test or the IPC bending test, and thus the copper foil is broken. Further, as long as the copper foil composite can be subjected to press working, the structure including the circuit can be made to conform to the shape of the product.

Accordingly, it is an object of the present invention to provide a method for preventing cracking of a copper foil by performing severe (complex) deformation different from uniaxial bending such as press working, thereby improving workability and further stably exhibiting corrosion resistance and electrical contact for a long period of time. A copper foil composite having properties, a molded body, and a method for producing the same.

The present inventors have found that by transferring the deformation behavior of the resin layer to the copper foil, the copper foil is also deformed in the same manner as the resin layer, so that the shrinkage of the copper foil is less likely to occur and the ductility is improved, thereby preventing the copper foil from being broken. The present invention has been completed. That is, the characteristics of the resin layer and the copper foil are defined in such a manner that the deformation behavior of the resin layer is transmitted to the copper foil. Further, in order to stably exhibit corrosion resistance and electrical contact performance for a long period of time, a coating layer on the surface of the copper foil is defined.

That is, the copper foil composite volume layer of the present invention has a copper foil and a resin layer, and the thickness of the copper foil is t ₂ (mm), and the stress of the copper foil when the tensile strain is 4% is f ₂ ( MPa), the thickness of the resin layer is t ₃ (mm), and when the stress of the resin layer at a tensile strain of 4% is f ₃ (MPa), the formula 1: (f ₃ × t ₃ ) is satisfied. / (f ₂ × t ₂ ) ≧ 1, and the copper foil and the resin layer are 180° peeled off and the strength is set to f ₁ (N/mm), and the tensile strain of the copper foil composite is 30%. When the thickness of the copper foil composite is T (mm), the formula 2:1≦24.3f ₁ /(F×T) is satisfied; On the surface of the resin layer, a Ni layer and/or a Ni alloy layer having a total thickness of 0.001 to 5.0 μm are formed.

Preferably, the total thickness of the Ni layer and/or the Ni alloy layer is 0.001 to 0.50 μm.

Preferably, the above formula 1 and formula 2 are at a temperature that does not reach the glass transition temperature of the above resin layer. Established.

Preferably, the ratio 1/L of the tensile strain at break 1 of the copper foil composite to the tensile strain at break L of the resin layer is 0.7 to 1.

The molding system of the present invention is obtained by processing the above metal foil composite. The molded article of the present invention can be processed three-dimensionally by, for example, press working, protrusion processing using upper and lower molds, and other processing such as drawing processing.

The method for producing a molded article of the present invention is to process the metal foil composite described above.

According to the present invention, it is possible to obtain a severe (complex) deformation different from uniaxial bending such as press working, thereby preventing the copper foil from being broken and having excellent workability, and further stably exhibiting corrosion resistance and electrical contact performance for a long period of time. Copper foil composite.

2‧‧‧punching machine

4‧‧‧Base

10‧‧‧ cup test device

20‧‧‧Test strips

R‧‧‧ Radius

f ₁ ‧‧‧180° peeling strength of copper foil and resin layer

F‧‧‧Strength of tensile strain at 30% of copper foil composite

Thickness of T‧‧‧ copper foil composite

Figure 1 is a graph showing the relationship between f ₁ and (F × T).

Fig. 2 is a view showing the configuration of a cupping test apparatus for evaluating workability.

The copper foil composite system of the present invention is formed by laminating a copper foil and a resin layer. The copper foil composite of the present invention can be applied to, for example, an FPC (Flexible Printed Circuit Board), an electromagnetic wave mask, an RF-ID (wireless IC tag), a planar heat generating body, and a heat sink, but is not limited thereto. .

<copper foil>

The thickness t _{2 of the} copper foil is preferably 0.004 to 0.05 mm (4 to 50 μm). When t _{2 is} less than 0.004 mm (4 μm), the ductility of the copper foil is remarkably lowered, and the workability of the copper foil composite is not improved. The copper foil preferably has a tensile strain at break of 4% or more. When t ₂ exceeds 0.05 mm (50 μm), the influence of the characteristics of the copper foil single body when the copper foil composite is formed is largely exhibited, and the workability of the copper foil composite is not improved.

As the copper foil, a rolled copper foil, an electrolytic copper foil, a copper foil obtained by metallization, or the like can be used. However, it is preferably a rolled copper which is excellent in workability by recrystallization and can reduce strength (f ₂ ). Foil. In the case where a treatment layer for subsequent rust prevention is formed on the surface of the copper foil, it is also considered to be included in the copper foil.

<Resin layer>

The resin layer is not particularly limited, and the resin material may be applied to the copper foil to form a resin layer, but is preferably a resin film which can be attached to the copper foil. Examples of the resin film include PET (polyethylene terephthalate) film, PEN (polyethylene naphthalate), PI (polyimide) film, LCP (liquid crystal polymer) film, and PP ( Polypropylene) film.

As a method of laminating the resin film and the copper foil, an adhesive may be used between the resin film and the copper foil, or the resin film may be thermocompression bonded to the copper foil. Further, when the strength of the adhesive layer is low, it is difficult to improve the workability of the copper foil composite. Therefore, the strength of the adhesive layer is preferably 1/3 or more of the stress (f ₃ ) of the resin layer. The reason for this is that, in the present invention, by transferring the deformation behavior of the resin layer to the copper foil, the copper foil is deformed in the same manner as the resin layer, so that the shrinkage of the copper foil is less likely to occur and the ductility is improved. The idea is that if the strength of the adhesive layer is low, the deformation of the adhesive layer is moderated, and the behavior of the resin is not transmitted to the copper foil.

Further, in the case of using an adhesive, the properties of the resin layer described below are intended to combine the adhesive layer and the resin layer.

The thickness t _{3 of the} resin layer is preferably from 0.012 to 0.12 mm (12 to 120 μm). When t _{3 is} less than 0.012 mm (12 μm), there is a case where (f ₃ × t ₃ ) / (f ₂ × t ₂ ) < When t _{3 is} thicker than 0.12 mm (120 μm), the flexibility (flexibility) of the resin layer is lowered and the rigidity is excessively high, and the workability is deteriorated. The resin layer preferably has a tensile strain at break of 40% or more.

<copper foil composite>

The combination of the copper foil composite in which the copper foil and the resin layer are laminated may be a two-layer structure of a copper foil/resin layer or a three-layer structure of a copper foil/resin layer/copper foil. In the case where a copper foil (copper foil/resin layer/copper foil) is present on both sides of the resin layer, the value of the whole (f ₂ × t ₂ ) is set to be calculated for each of the two layers of copper foil. The values of (f ₂ × t ₂ ) are added together.

<180° peeling strength>

Copper foil is easy to shrink in the thickness direction because of its thin thickness. If shrinkage occurs, the copper foil is broken, so ductility is lowered. On the other hand, the resin layer has a feature that it is less likely to cause shrinkage upon stretching (the area of uniform strain is wider). Therefore, in the composite of the copper foil and the resin layer, the deformation behavior of the resin layer is transmitted to the copper foil, and the copper foil is also deformed in the same manner as the resin, so that the copper foil is less likely to shrink and the ductility is improved. At this time, if the bonding strength between the copper foil and the resin layer is low, the deformation behavior of the resin layer cannot be transmitted to the copper foil, and the ductility is not improved (peeling and copper is broken).

Therefore, the bonding strength must be increased. As the adhesion strength, the shear adhesion is considered to be a directness index. However, if the adhesion strength is increased and the shear adhesion is equal to the strength of the copper foil composite, the portion other than the adhesion surface is broken, which makes it difficult. The measurement was carried out.

According to this case, the value of 180° peeling followed by the strength f ₁ is used in the present invention. The shearing strength was completely different from the absolute value of the 180° peeling strength, but the workability or tensile elongation was found to be related to the 180° peeling strength. Therefore, the 180° peeling strength was used as an index of the strength.

Here, it is considered that "strength at break = shear adhesion" is considered to be "30% flow stress ≦ shear adhesion force" when it is required to have a tensile strain of 30% or more. When a tensile strain of 50% or more is required, it becomes "50% flow stress ≦ shear adhesion". Further, according to the experiment of the inventors of the present invention, when the tensile strain is 30% or more, the workability is improved. Therefore, the strength at which the tensile strain is 30% is used as the strength F of the copper foil composite as follows.

Figure 1 is _a graph showing the relationship experimental and (F × T) of f, f of the following Examples and Comparative Examples of ₁ and the value (F × T) of each of the embodiments drawn. (F×T) is the force applied to the copper foil composite at a tensile strain of 30%, and if this is regarded as the minimum shear strength necessary for improving the workability, then f ₁ and (F) ×T) has the same absolute value, and the two are easy to see the correlation in the slope 1.

However, in Fig. 1, not all of the data f ₁ and (F × T) are the same correlation, and for each of the comparative examples with poor workability, the correlation coefficient with respect to f ₁ of (F × T) (that is, With the origin of Fig. 1, the slope of f ₁ with respect to (F × T) is small, and correspondingly, the 180° peeling is inferior in strength. On the other hand, the slope of each example is larger than the slope of each comparative example, and the inclination of the embodiment 17 (which is just broken when the strain is 30%) is 1/24.3, so the value is regarded as The correlation coefficient between the minimum shear strength and the 180° peel strength required to improve the workability. That is, the shearing force was regarded as 180° peeling and then 24.3 times the strength f ₁ .

Further, in the case of Comparative Example 3, the slope of FIG. 1 exceeded 1/24.3, but the following formula 1: (f ₃ × t ₃ ) / (f ₂ × t ₂ ) did not reach 1, so the workability deteriorated. .

180° peeling followed by strength (N/mm) per unit width.

When the copper foil composite has a three-layer structure and a plurality of subsequent faces exist, the 180° peeling in each of the adjoining faces is used to have the lowest strength. The reason is that the most vulnerable side will be peeled off.

Further, the pressure or temperature conditions at the time of laminating the copper foil and the resin layer can be changed to improve the bonding strength. It is preferable to simultaneously increase the pressure and temperature at the time of laminating without damaging the resin layer.

As a method of improving the adhesive strength between the copper foil and the resin layer, a Cr oxide layer is provided on the surface of the copper foil (the surface on the resin layer side, hereinafter referred to as "the adhesion surface" as appropriate) by chromate treatment or the like. Alternatively, the copper foil surface may be subjected to a roughening treatment, or a Ni layer or a Ni alloy layer may be provided on the surface of the copper foil, or a Cr oxide layer may be provided after the surface of the copper foil is coated with Ni. Further, as described below, a Ni layer or a Ni alloy layer is formed on the surface (non-bonding surface) of the copper foil opposite to the resin layer, and the Ni layer or the Ni alloy layer may be formed on the non-bonding surface while being the same Step by step A Ni layer or a Ni alloy layer. Alternatively, a Cr oxide layer may be formed after forming a Ni layer or a Ni alloy layer on the succeeding surface.

The thickness of the Cr oxide layer on the surface side is preferably 5 to 100 μg/dm ² in terms of the weight of Cr. This thickness can be calculated from the chromium content obtained by wet analysis. Further, the presence of the Cr oxide layer can be determined by whether or not the Cr can be detected by X-ray photoelectron spectroscopy (XPS) (the peak of Cr is displaced by oxidation).

The thickness of the Ni layer or the Ni alloy layer on the surface side is preferably 0.001 to 5.0 μm. When the thickness of the Ni layer or the Ni alloy layer exceeds 5.0 μm, the ductility of the copper foil (and the copper foil composite) may be lowered.

Further, the pressure or temperature conditions at the time of laminating the copper foil and the resin layer can be changed to improve the bonding strength. It is preferable to simultaneously increase the pressure and temperature at the time of laminating without damaging the resin layer.

A Ni layer and/or a Ni alloy layer having a total thickness of 0.001 to 5.0 μm are formed in the copper foil on the surface (non-bonding surface) on which the resin layer is not laminated, in order to provide stable electrical contact properties for a long period of time. If the total thickness of the layers is less than 0.001 μm, stable electrical contact properties cannot be obtained. The thicker the total thickness of the layers is, the more stable the electrical contact performance is. However, even if the total thickness exceeds 5.0 μm, the above effects are saturated. The total thickness of the Ni layer and/or the Ni alloy layer is preferably 0.001 to 0.50 μm, more preferably 0.005 to 0.10 μm.

Further, the Ni alloy layer is preferably an alloy containing 20% by weight or more of Ni, and further containing 5% by weight or more of Zn, Sn, Co, Cr, Mn, V, P, B, W, Mo, and Fe. Above, the remaining part is an unavoidable impurity.

Further, at least one of the Ni layer or the Ni alloy layer described above may be formed on the non-contiguous surface of the copper foil. Further, in the case where both the Ni layer and the Ni alloy layer are formed on the non-contiguous surface of the copper foil, the Ni layer/Ni alloy layer may be used from the outermost surface, or the Ni alloy may be used from the outermost surface. The order of the layers/Ni layers. Moreover, the "total thickness" means the total value of the thickness of the Ni layer and the thickness of the Ni alloy layer.

<(f ₃ ×t ₃ )/(f ₂ ×t ₂ )>

Next, the meaning of ((f ₃ × t ₃ ) / (f ₂ × t ₂ )) (hereinafter referred to as "Formula 1") of the patent application scope will be described. Since the copper foil composite system has a copper foil and a resin layer having the same width (size), the formula 1 represents the ratio of the force applied to the copper foil constituting the copper foil composite and the resin layer. Therefore, the ratio of 1 or more means that more force is applied to the resin layer side, and the strength of the resin layer side is higher than that of the copper foil. Moreover, the fact that the copper foil is not broken indicates good processability.

On the other hand, if (f ₃ × t ₃ ) / (f ₂ × t ₂ ) < 1, the force is applied to the side of the copper foil, so that the deformation behavior of the resin layer is not transmitted to the copper. The foil acts to deform the copper foil in the same manner as the resin.

Here, f ₂ and f ₃ may be stresses under the same strain amount after plastic deformation, but considering the strain at break of the tensile fracture strain of the copper foil and the plastic deformation of the resin layer (for example, PET film), It is a tensile strain of 4% strain. Further, f ₂ and f ₃ (and f ₁ ) are all set to values of MD (Machine Direction).

<24.3f ₁ /(F×T)>

Next, the meaning of the patent application range (24.3f ₁ /(F×T)) (hereinafter referred to as "Formula 2") will be described. As described above, since the shearing force is 180° peeling and then the strength f ₁ is about 24.3 times, 24.3f ₁ represents the minimum bonding strength necessary for improving the workability of the copper foil and the resin layer, wherein the shearing is performed. The cutting force directly indicates the minimum bonding strength between the copper foil and the resin layer necessary for improving the workability. On the other hand, (F × T) is a force applied to the copper foil composite, and therefore, Formula 2 becomes a ratio of the adhesion strength between the copper foil and the resin layer and the tensile resistance of the copper foil composite. Further, when the copper foil composite is stretched, a shear stress is applied to the interface between the copper foil and the resin layer by a copper foil to be locally deformed and a resin to be uniformly stretched. Therefore, if the strength is lower than the shear stress, the copper and the resin layer are peeled off, and the deformation behavior of the resin layer cannot be transmitted to the copper foil, so that the ductility of the copper foil is not improved.

In other words, when the ratio of the formula 2 is less than 1, the subsequent strength becomes weaker than the force applied to the copper foil composite, and the copper foil and the resin are easily peeled off, and the copper foil is broken by processing such as press molding.

When the ratio of Formula 2 is 1 or more, the copper and the resin layer are not peeled off, and the deformation behavior of the resin layer can be transmitted to the copper foil, thereby improving the ductility of the copper foil. Further, the higher the ratio of the formula 2, the better, but it is usually difficult to achieve a value of 10 or more. Therefore, it is preferable to set the upper limit of the formula 2 to 10.

Further, it is considered that the larger the 24.3f ₁ /(F×T), the more the workability is improved, but the tensile strain l of the resin layer is not proportional to 24.3f ₁ /(F×T). This is caused by the influence of (f ₃ × t ₃ ) / (f ₂ × t ₂ ), the ductility of the copper foil and the resin layer monomer, but as long as it satisfies 24.3f ₁ /(F × T)≧ 1. A combination of a copper foil of (f ₃ × t ₃ ) / (f ₂ × t ₂ ) ≧ 1 and a resin layer, whereby a composite having desired workability can be obtained.

Here, the reason why the strength at the tensile strain of 30% is used as the strength F of the copper foil composite is that, as described above, when the tensile strain is 30% or more, the workability is improved. Further, the reason for this is that the tensile test of the copper foil composite is carried out, and as a result, the tensile stress is 30%, and the flow stress is greatly deteriorated by the strain, and even after 30%, the tensile stress is obtained. The tensile strain does not cause a large difference in flow stress (slightly work hardening, but the slope of the curve becomes quite small).

In addition, when the tensile strain of the copper foil composite is not 30% or more, the tensile strength of the copper foil composite is F.

As described above, the copper foil composite system of the present invention can prevent the copper foil from being broken and excellent in workability even if it is subjected to severe (complex) deformation such as press processing which is different from uniaxial bending. In particular, the invention is suitable for stereolithography such as press processing. By conducting a copper foil composite The three-dimensional forming can make the copper foil composite into a complicated shape or increase the strength of the copper foil composite. For example, the copper foil composite itself can be used as a frame of various power supply circuits, thereby achieving the number of parts or costs. Reduced.

<l/L>

The ratio l/L of the tensile strain at break l of the copper foil composite to the tensile rupture strain L of the resin layer monomer is preferably 0.7 to 1.

Generally, the tensile strain at break of the resin layer is overwhelmingly higher than the tensile strain at break of the copper foil, and likewise, the strain at break of the resin layer is overwhelmingly higher than the tensile strain at break of the copper foil composite. On the other hand, as described above, in the present invention, the deformation behavior of the resin layer is transmitted to the copper foil to improve the ductility of the copper foil, and accordingly, the tensile strain at break of the copper foil composite can be improved to the resin. The tensile fracture strain of the layer monomer is 70~100%. Further, when the ratio l/L is 0.7 or more, the press formability is further improved.

Further, the tensile strain at break l of the copper foil composite is the tensile strain at break when the tensile test is performed, and is set to be the value when the resin layer and the copper foil are simultaneously broken, and is set to be broken when the copper foil is first broken. The value of time.

<Tg of resin layer>

In general, the strength of the resin layer is lowered at a high temperature or the force is lowered, so that it becomes difficult to satisfy (f ₃ × t ₃ ) / (f ₂ × t ₂ ) ≧ 1, or 1 ≦ 24.3f ₁ / (F × at a high temperature. T). For example, at a temperature higher than the Tg (glass transition temperature) of the resin layer, it may become difficult to maintain the strength or the adhesion force of the resin layer. If the temperature is less than Tg, it may become easy to maintain the strength of the resin layer or Then the tendency of force. That is, if the temperature of the Tg (glass transition temperature) of the resin layer is not reached (for example, 5 ° C to 215 ° C), the copper foil composite becomes easily satisfied (f ₃ × t ₃ ) / (f ₂ × t ₂ ) ≧ 1, and 1 ≦ 24.3f ₁ / (F × T). In addition, even if the temperature is less than Tg, it is considered that the strength or the adhesion force of the resin layer having a higher temperature becomes smaller, and it becomes difficult to satisfy Formulas 1 and 2 (refer to Example 19 below). twenty one).

Further, it is clear that when the formula 1 and the formula 2 are satisfied, the ductility of the copper foil composite can be maintained even at a relatively high temperature (for example, 40 ° C to 215 ° C) which does not reach the Tg of the resin layer. If the ductility of the copper foil composite is maintained even at a relatively high temperature (for example, 40 ° C to 215 ° C) of the Tg of the resin layer, excellent workability is exhibited in a method such as warm pressing. Further, in the case of the resin layer, the moldability is good in the case where the temperature is higher. Further, since it is subjected to warm pressing in order to maintain the shape after pressing (in order not to return to the original state due to elastic deformation), it is also preferable in this point even if the temperature of the Tg of the resin layer is not relatively high. (For example, 40 ° C ~ 215 ° C), can also maintain the ductility of the copper foil composite.

Further, in the case where the copper foil composite contains the adhesive layer and the resin layer, the Tg of the layer having the lowest Tg (glass transition temperature) is used.

[Examples]

<Manufacture of Copper Foil Composite>

The ingot formed of tough pitch copper is subjected to hot rolling, and after removing the oxide by surface cutting, the cold rolling, annealing and pickling are repeated to make it thin to the thickness t _{2 of} Table 1 ( Mm), finally annealing is performed to ensure workability, and rust-preventing treatment is performed by benzotriazole to obtain a copper foil. In order to make the copper foil a uniform structure in the width direction, the tension of the cold pressing delay and the rolling direction of the rolled material are uniform. In the subsequent annealing, a plurality of heaters are used for temperature management so that the width direction becomes a uniform temperature distribution, and the temperature of the copper is measured and controlled.

Further, after the surface treatment shown in Table 1 was performed on both sides of the obtained copper foil, the resin film (resin layer) shown in Table 1 was used, and the vacuum was applied at a temperature (Tg + 50 ° C or more of the resin layer). A resin film was laminated under pressure (pressure: 200 N/cm ² ) to prepare a copper foil composite having a layer structure shown in Table 1. In Example 5, a copper foil and a resin film were laminated using an adhesive to form a copper foil composite.

Further, in Table 1, Cu represents a copper foil, PI represents a polyimide film, and PET represents a polyethylene terephthalate film. Further, the Tg of PI and PET were 220 ° C and 70 ° C, respectively.

Further, a Ni (alloy) layer having a thickness shown in Table 1 was formed on one side of the copper foil (the surface not to be adjacent to the resin layer). The surface treatment shown in Table 1 was carried out on the opposite side of the copper foil (the same surface as the resin layer). The conditions of the surface treatment are as follows.

Chromate treatment: Electrolytic treatment was carried out using a chromate bath (K ₂ Cr ₂ O ₇ : 0.5 to 5 g/L) at a current density of 1 to 10 A/dm ² . The adhesion amount of the chromate-treated Cr oxide layer was set to 35 μg/dm ² .

Covered Ni+chromate treatment: Ni plating bath (Ni ion concentration: 1~30g/L watt bath), plating temperature 25~60°C, current density 0.5~10A/dm ² after Ni plating, and The chromate treatment was carried out in the same manner as above. The thickness of the coated Ni was set to 0.010 μm.

Roughening treatment: use treatment liquid (Cu: 10~25g/L; H ₂ SO ₄ : 20~100g/L), temperature 20~40°C, current density 30~70A/dm ² , electrolysis time 1~5 seconds Perform electrolytic treatment. Thereafter, a Ni-Co plating solution (Co ion concentration: 5 to 20 g/L; Ni ion concentration: 5 to 20 g/L; pH: 1.0 to 4.0) was used, and the temperature was 25 to 60 ° C, and the current density was 0.5 to 0.5. 10A/dm ² was plated with Ni-Co.

Further, the formation of the Ni (alloy) layer on the non-adhesion surface of the copper foil was carried out under the same conditions as those of the above-mentioned coated Ni.

Further, in the case of Example 24, a Ni-Zn layer having a thickness of 2.5 μm was formed on the non-bonding surface of the copper foil. On the other hand, after the Ni-Zn layer was formed on the succeeding surface of the copper foil, the same chromate treatment as described above was carried out. The Ni-Zn layer is made by using a Ni-Zn plating bath (Ni ion concentration: 15-20 g/L; Zn ion concentration: 10-20 g/L), plating bath temperature 50 ° C, current density 4.0 A/dm ² It is formed by plating. The Ni-Zn layer was analyzed, and as a result, the alloy composition was Ni:Zn = 75:25 (wt%).

In the case of Example 25, a Ni-P layer having a thickness of 2.5 μm was formed on the non-adjacent surface of the copper foil. On the other hand, after the Ni-P layer was formed on the succeeding surface of the copper foil, the same chromate treatment as described above was carried out. The Ni-P layer is plated by using a Ni-P plating bath (Ni ion concentration: 15-20 g/L; P concentration: 5 g/L), a plating solution temperature of 50 to 60 ° C, and a current density of 4 A/dm ² . Formed by the application. The Ni-P layer was analyzed, and as a result, the alloy composition was Ni:P = 95:5 (wt%).

In the case of Example 26, a Ni-Sn layer having a thickness of 2.5 μm was formed on the non-bonding surface of the copper foil. On the other hand, after the Ni-Sn layer was formed on the succeeding surface of the copper foil, the same chromate treatment as described above was carried out. The Ni-Sn layer is made by using a Ni-Sn plating bath (Ni ion concentration: 15-20 g/L; Sn ion concentration: 10-15 g/L), plating bath temperature 45 ° C, current density 4.0 A/dm ² It is formed by plating. The Ni-Sn layer was analyzed, and as a result, the alloy composition was Ni:Sn=80:20 (wt%).

In the case of Example 27, each layer was formed in the same manner as in Example 26 except that the thickness of the Ni-Sn layer of the non-adhesive surface of the copper foil was changed to 0.3 μm. The Ni-Sn layer was analyzed, and as a result, the alloy composition was Ni:Sn=80:20 (wt%).

In the case of Example 28, a Ni layer and a Sn layer were formed in the order of the Ni layer and the Sn layer on the non-bonding surface of the copper foil, and then heat treatment was applied at 180 ° C for 7 hours in a nitrogen atmosphere. On the other hand, after the Ni layer was formed on the succeeding surface of the copper foil, the same chromate treatment as described above was carried out. The Ni layer was formed by using a Ni bath of sulfuric acid (Ni ion concentration: 25 g/L), a plating solution temperature of 45 ° C, and a current density of 4 A/dm ² . The Sn layer was formed by using a phenolsulfonic acid bath (Sn ion concentration: 30 g/L), a plating solution temperature of 45 ° C, and a current density of 8 A/dm ² . The secondary electron image of the plated cross section on the non-adjacent surface side of the copper foil was observed by SEM. As a result, two layers were formed, and the layer on the outermost layer side was analyzed. As a result, Ni:Sn=30:70 (wt%), Based on the result, it was judged to be a Ni-Sn layer. The layer on the side of the substrate was analyzed, and as a result, Sn was 5 wt% or less, and the remainder was Ni, and based on the result, it was judged to be a Ni layer. The thickness of each layer was 0.1 μm (total thickness 0.2 μm).

The adhesion amount of the Cr oxide layer, the thickness of the Ni layer and the Ni alloy layer are 100 mm × 100 mm copper foil in which the layers are formed in a solution in which HNO ₃ (2% by weight) and HCl (5% by weight) are mixed. The solution was dissolved and quantified by ICP emission spectroscopic analyzer (manufactured by SII NanoTechnology Inc., model SFC-3100) to quantify the concentration of each metal in the solution. Each sample was measured five times, and the average value thereof was defined as the adhesion amount (thickness).

Further, the thickness of the Ni layer and the Ni alloy layer is obtained by converting the mass of each metal obtained by the above method and using a known specific gravity.

<Tensile test>

A plurality of short tensile test pieces having a width of 12.7 mm were prepared from the copper foil composite. In the tensile test of the copper foil and the resin film, the copper foil monomer and the resin film monomer before lamination were formed into a short strip shape of 12.7 mm.

Then, a tensile test was performed in a direction parallel to the rolling direction of the copper foil by a tensile tester in accordance with JIS-Z2241. The test temperatures at the time of the tensile test are shown in Table 1.

<180° peel test>

A 180° peel test was performed, and 180° peeling followed by strength f _{1 was} measured. First, a plurality of strip-shaped peeling test pieces each having a width of 12.7 mm were produced from a copper foil composite. The copper foil surface of the test piece was fixed to a SUS (stainless steel) plate, and the resin layer was peeled off in the 180° direction. In the embodiment in which the copper foil was present on both surfaces of the resin layer, after the copper foil of one side was removed, the copper foil side of the opposite surface was fixed to the SUS plate, and the resin layer was peeled off in the 180° direction. Other conditions are based on JIS-C5016.

Further, in the JIS standard, the copper foil layer is peeled off, and in the embodiment, the resin layer is peeled off in order to reduce the influence of the thickness and rigidity of the copper foil.

<Evaluation of processability>

The evaluation of the workability was carried out using the cupping test apparatus 10 shown in Fig. 2 . The cupping test apparatus 10 includes a susceptor 4 and a puncher 2, and the pedestal 4 has a truncated cone-shaped inclined surface. The truncated cone has a tapered front end from the top to the bottom, and the angle of the inclined surface of the truncated cone is 60° from the horizontal plane. Further, a circular hole having a diameter of 15 mm and a depth of 7 mm was connected to the lower side of the truncated cone. On the other hand, the punching machine 2 is formed into a hemispherical cylinder having a diameter of 14 mm at the front end, and can be inserted into the hemispherical portion of the front end of the punching machine 2 into the circular hole of the truncated cone.

Further, the connecting portion of the tapered front end of the truncated cone and the circular hole at the lower side of the truncated cone is rounded with a radius (r) = 3 mm.

Then, the copper foil composite was punched into a disk-shaped test piece 20 having a diameter of 30 mm, and the copper foil composite was placed on the inclined surface of the truncated cone of the susceptor 4, and the punch 2 was pressed down from the test piece 20 and Insert into the round hole of the base 4. Thereby, the test piece 20 is formed into a conical cup shape.

Further, in the case where the resin layer is present only on one side of the copper foil composite, the resin layer is placed on the susceptor 4 toward the top. Further, when a resin layer is present on both surfaces of the copper foil composite, the resin layer next to the M surface is placed upward and placed on the susceptor 4. In the case where both sides of the copper foil composite are Cu, either side may face upward.

The presence or absence of cracking of the copper foil in the test piece 20 after the molding was judged by visual inspection, and the workability was evaluated based on the following criteria.

◎: The copper foil is not broken, and there is no wrinkle in the copper foil.

○: The copper foil is not broken, but there is a slight wrinkle in the copper foil.

×: Copper foil is broken

<Evaluation of Corrosion Resistance>

Under the pressure of 98±10 KPa, the surface of the copper foil laminate which is not laminated with the resin layer is adjusted to a brine having a sodium chloride concentration of 5±1 wt% and a pH of 6.5 to 7.2 at a temperature of 35±2° C. After an hour of spraying, the appearance was visually observed. Further, the surface was analyzed for the presence or absence of the copper foil component by XPS.

◎: No discoloration was confirmed, and the copper foil was not exposed (the copper foil component was not detected from the surface)

○: It was confirmed that there was a white-colored discoloration, and the copper foil was not exposed (the copper foil component was not detected from the surface)

×: It was confirmed that black discoloration due to oxidation of copper foil or discoloration due to rust caused by green, and copper foil was exposed (copper foil component was detected from the surface)

<Evaluation of the stability of electrical contact performance>

After each test piece was heated at 180 ° C for 1,000 hours in the atmosphere, the contact resistance was measured on the surface of the copper foil on which the resin layer was not laminated. The electric contact simulator CRS-1 manufactured by Yamazaki Seiki Co., Ltd. was used for measurement by a four-terminal method. Probe: Gold probe, contact load: 40 g, sliding speed: 1 mm/min, sliding distance: 1 mm.

○: Contact resistance is less than 10mΩ

×: The contact resistance is 10 mΩ or more.

The results obtained are shown in Tables 1 and 2. Further, the test temperature shown in Table 1 for F, f _1, f _2, temperature f _3, and the evaluation of workability.

As is clear from Tables 1 and 2, in the case of each embodiment, (f ₃ × t ₃ ) / (f ₂ × t ₂ ) ≧ 1, and 1 ≦ 24.3f ₁ / (F × T) are simultaneously satisfied. ), and thus become excellent in workability. Moreover, in the case of each of the examples, electrical contact performance and corrosion resistance were also excellent.

Further, when Example 15 using the copper foil laminate having the same structure was compared with Example 19, it was found that the tensile test was carried out at room temperature (about 25 ° C) in comparison with Example 19. In Example 15, the value of (f ₃ × t ₃ ) / (f ₂ × t ₂ ) was large, and in Example 19, the resin layer became weak due to an increase in the test temperature (f _{3 was} decreased).

On the other hand, in the case of Comparative Example 1 in which the resin film was laminated without subjecting the copper foil to surface treatment, the strength was lowered, and the value of 24.3f ₁ /(F × T) was less than 1, and the workability was deteriorated.

In the case of Comparative Examples 2 and 4 in which the pressure at the time of lamination was reduced to 100 N/cm ² , the strength was lowered, and the value of 24.3 f ₁ /(F × T) was less than 1, and the workability was deteriorated.

In the case of Comparative Example 3 in which the thickness of the resin film was reduced, the strength of the resin film was weaker than that of the copper foil, and the value of (f ₃ × t ₃ ) / (f ₂ × t ₂ ) was less than 1, and workability was obtained. Deterioration.

In the case of Comparative Example 5 in which the thickness of Ni plating not on the surface of the resin layer was less than 0.001 μm, electrical contact performance and corrosion resistance were deteriorated.

f ₁ ‧‧‧180° peeling strength of copper foil and resin layer

F‧‧‧Strength of tensile strain at 30% of copper foil composite

Thickness of T‧‧‧ copper foil composite

Claims (7)

A copper foil composite having a copper foil and a resin layer laminated thereon, wherein the thickness of the copper foil is t ₂ (mm), and the stress of the copper foil when the tensile strain is 4% is f ₂ (MPa), the thickness of the resin layer is t ₃ (mm), and when the stress of the resin layer at a tensile strain of 4% is f ₃ (MPa), the formula 1: (f ₃ × t ₃ ) is satisfied. / (f ₂ × t ₂ ) ≧ 1; and the copper foil is peeled off from the resin layer by 180° and the strength is set to f ₁ (N/mm), and the tensile strain of the copper foil composite is 30%. When the thickness of the copper foil composite is T (mm), the formula 2:1≦24.3f ₁ /(F×T) is satisfied; the layer is not laminated in the copper foil. On the surface of the resin layer, a Ni layer and/or a Ni alloy layer having a total thickness of 0.001 to 5.0 μm are formed. The copper foil composite according to claim 1, wherein the Ni layer and/or the Ni alloy layer have a total thickness of 0.001 to 0.50 μm. The copper foil composite according to claim 1, wherein the formulas 1 and 2 are established at a temperature that does not reach the glass transition temperature of the resin layer. The copper foil composite according to claim 2, wherein the formulas 1 and 2 are established at a temperature that does not reach the glass transition temperature of the resin layer. The copper foil composite according to any one of claims 1 to 4, wherein a ratio l/L of the tensile strain at break l of the copper foil composite to the tensile strain at break L of the resin layer is 0.7~1. A molded body obtained by processing a copper foil composite according to any one of claims 1 to 5. A method of manufacturing a shaped body, which is in any one of claims 1 to 5 The copper foil composite is processed.