CN104010810A - Copper foil composite, molded body, and manufacturing method thereof - Google Patents

Abstract

The invention provides a copper foil composite which can prevent the copper foil from cracking and has excellent processability even if pressing processing such as severe (complex) deformation different from uniaxial bending is carried out, a formed body and a manufacturing method thereof. The invention relates to a copper foil composite body with a copper foil and a resin layer laminated, wherein the thickness of the copper foil is t₂(mm), the stress of the copper foil at 4% tensile strain is defined as f₂(MPa), the thickness of the resin layer is t₃(mm), the stress of the resin layer at a tensile strain of 4% is defined as f₃(MPa), formula 1 is satisfied: (f)₃×t₃）/（f₂×t₂) Not less than 1, and f is the 180 DEG peel adhesion strength between the copper foil and the resin layer₁(N/mm), wherein F (MPa) is the strength at 30% tensile strain of the copper foil composite, and T (mm) is the thickness of the copper foil composite, the following formula 2 is satisfied: 1 is less than or equal to 33f₁And (FxT), a Ni layer and/or a Ni alloy layer having a total thickness of 0.001 to 5.0 μm is formed on the surface of the copper foil on which the resin layer is not laminated.

Description

Copper foil composite, molded body, and manufacturing method thereof

technical field

The present invention relates to a copper foil composite formed by laminating copper foil and a resin layer, a molded body, and a manufacturing method thereof.

Background technique

Copper foil composites made of laminated copper foil and resin layers are used in FPC (flexible printed circuit boards), electromagnetic wave shielding materials, RF-ID (wireless IC tags), planar heating elements, and radiators, etc. For example, in the case of FPC, a circuit of copper foil is formed on a base resin layer, and a cover layer film for protecting the circuit covers the circuit to form a laminated structure of resin layer/copper foil/resin layer.

Therefore, the workability of such copper foil composites requires bendability represented by MIT bendability and high-cycle bendability represented by IPC bendability, and copper foil composites excellent in bendability or bendability have been proposed ( For example, Patent Documents 1 to 3). For example, FPC can be bent in movable parts such as the hinge part of a mobile phone, or it can be bent and used to reduce the space of the circuit. Designed in such a way that it bends without becoming a harsh deformation mode.

In addition, when the copper foil composite is used as an electromagnetic wave shielding material, etc., it becomes a resin layer/copper foil laminated structure, and the surface of such a copper foil composite is required to exhibit corrosion resistance and long-term stable electrical contact performance.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2010-100887

Patent Document 2: Japanese Patent Laid-Open No. 2009-111203

Patent Document 3: Japanese Unexamined Patent Publication No. 2007-207812.

Contents of the invention

The problem to be solved by the invention

However, when the above-mentioned copper foil composite is subjected to press processing or the like, it becomes a severe (complex) deformation mode different from the MIT bending test or the IPC bending test, so there is a problem that the copper foil is broken. Furthermore, as long as the copper foil composite can be press-worked, the structure including the circuit can be made to conform to the shape of the product.

Therefore, an object of the present invention is to provide a copper foil that prevents cracking of the copper foil even when subjected to severe (complex) deformation different from uniaxial bending, such as press working, and has excellent processability, and further exhibits corrosion resistance and corrosion resistance stably over a long period of time. Copper foil composite with electrical contact performance, molded body and manufacturing method thereof.

technical means to solve problems

The inventors of the present invention have found that by transmitting 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, the ductility is improved, and the copper foil is prevented from cracking, thereby completing the present invention. invention. That is, the properties of the resin layer and copper foil are specified so that the deformation behavior of the resin layer is transmitted to the copper foil. Furthermore, in order to exhibit corrosion resistance and electrical contact performance stably for a long time, the coating layer on the surface of copper foil is prescribed|regulated.

That is, the copper foil composite of the present invention is laminated with a copper foil and a resin layer, where the thickness of the copper foil is t ₂ (mm), and the stress of the copper foil at a tensile strain of 4% is f ₂ ( MPa), when the thickness of the above resin layer is set as t ₃ (mm), and the stress of the above resin layer when the tensile strain is 4% is set as f ₃ (MPa), formula 1 is satisfied: (f ₃ ×t ₃ ) /(f ₂ ×t ₂ )≥1, and when the 180° peel adhesion strength between the above-mentioned copper foil and the above-mentioned resin layer is set as f ₁ (N/mm), the tensile strain of the above-mentioned copper foil composite is 30% When the strength at the time is set as F (MPa), and the thickness of the above-mentioned copper foil composite is set as T (mm), formula 2 is satisfied: 1≤33f ₁ /(F×T); On the surface of the above-mentioned resin layer, a Ni layer and/or a Ni alloy layer having a total thickness of 0.001 to 5.0 μm is formed.

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

Preferably, the above formulas 1 and 2 are established at a temperature lower than the glass transition temperature of the resin layer.

Preferably, the ratio l/L of the tensile fracture strain l of the copper foil composite to the tensile fracture strain L of the resin layer alone is 0.7-1.

The molded article of the present invention is obtained by processing the above metal foil composite. The molded article of the present invention can be three-dimensionally processed by, for example, press processing, projection processing using upper and lower dies, drawing processing, or other processing.

The manufacturing method of the molded article of this invention processes the said metal foil composite.

Invention effect

According to the present invention, even if severe (complex) deformation other than uniaxial bending such as press processing is performed, it is possible to prevent copper foil from cracking and to achieve excellent processability, and to exhibit stable corrosion resistance and electrical contact performance over a long period of time. copper foil composite.

Description of drawings

FIG. 1 is a diagram experimentally showing the relationship between f ₁ and (F×T).

Fig. 2 is a diagram showing the configuration of a cupping test device for evaluating workability.

Detailed ways

The copper foil composite of the present invention is formed by laminating copper foil and resin layers. The copper foil composite of the present invention is applicable to, for example, FPC (flexible printed circuit board), electromagnetic wave shielding material, RF-ID (wireless IC tag), planar heating element, and radiator, 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 may be remarkably reduced and the workability of the copper foil composite may not be improved. The copper foil preferably has a tensile breaking strain of 4% or more. When t ₂ exceeds 0.05 mm (50 μm), the influence of the properties of the copper foil alone may appear significantly when the copper foil composite is formed, and the workability of the copper foil composite may not be improved.

As the copper foil, rolled copper foil, electrolytic copper foil, copper foil obtained by metallization, etc. can be used, but the rolled copper foil is preferably a rolled copper foil that has excellent workability due to recrystallization and can lower the strength (f ₂ ). When a treatment layer for adhesion and antirust is formed on the surface of the copper foil, these are also considered to be included in the copper foil.

＜Resin layer＞

The resin layer is not particularly limited, and the resin layer can be formed by applying a resin material to copper foil, but it is preferably a resin film that can be attached to copper foil. Examples of resin films include PET (polyethylene terephthalate) films, PEN (polyethylene naphthalate), PI (polyimide) films, LCP (liquid crystal polymer) films, 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 bonded to the copper foil by thermocompression. Moreover, since it becomes difficult to improve the processability of a copper foil composite body when the intensity|strength of an adhesive bond layer is low, it is preferable that the intensity|strength of an adhesive bond layer is 1/3 or more of the stress ( _f3 ) of a resin layer. The reason for this is that in the present invention, the technical idea of "transmitting the deformation behavior of the resin layer to the copper foil and deforming the copper foil in the same way as the resin layer, thereby making the shrinkage of the copper foil less likely to occur and improving the ductility" is adopted. If the strength of the adhesive bond layer is low, the deformation in the adhesive bond layer will be relaxed, and the behavior of the resin will not be transmitted to the copper foil.

In addition, when using an adhesive agent, the characteristic of the following resin layer is the object which combined the adhesive agent layer and the resin layer.

The thickness t ₃ of the resin layer is preferably 0.012 to 0.12 mm (12 to 120 μm). When t ₃ is less than 0.012 mm (12 μm), (f ₃ ×t ₃ )/(f ₂ ×t ₂ )<1 may be obtained. If _t3 is thicker than 0.12 mm (120 μm), the flexibility (flexibility) of the resin layer will decrease, the rigidity will become too high, and the processability will deteriorate. The resin layer preferably has a tensile breaking strain of 40% or more.

＜Copper Foil Composite＞

As a combination of the copper foil composite body which laminated|stacked the said copper foil and the resin layer, the two-layer structure of copper foil/resin layer, or the 3-layer structure of copper foil/resin layer/copper foil is mentioned. When there are copper foils on both sides of the resin layer (copper foil/resin layer/copper foil), the value of the overall (f ₂ ×t ₂ ) is each ( The value obtained by adding the values of f ₂ ×t ₂ ).

＜180°peel adhesive strength＞

Since copper foil is thin, shrinkage tends to occur in the thickness direction. When the shrinkage occurs, the copper foil is broken, so that the ductility decreases. On the other hand, the resin layer has the characteristic of being less likely to shrink when stretched (a wide area of uniform strain). Therefore, in the composite of copper foil and resin layer, by transmitting the deformation behavior of the resin layer to the copper foil, the copper foil is also deformed in the same way as the resin, so that the copper foil is less likely to shrink and the ductility is improved. At this time, if the adhesive 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 (the copper is broken due to peeling).

Therefore, it is necessary to increase the bonding strength. As the adhesive strength, the shear adhesive strength is considered as a direct indicator, but if the adhesive strength is increased to make the shear adhesive strength equal to the strength of the copper foil composite, the parts other than the adhesive surface will be broken , and thus become difficult to measure.

In this case, the value of the 180° peel adhesive strength f ₁ is used in the present invention. The absolute values of shear adhesive strength and 180° peel adhesive strength are completely different, but there is a correlation between processability or tensile elongation and 180° peel adhesive strength, so 180° peel adhesive strength is used as the adhesive strength. An indicator of bonding strength.

Here, it is actually considered that "strength at fracture = shear adhesion", for example, when a tensile strain of 30% or more is required, it is considered to be "30% flow stress ≤ shear adhesion". When a tensile strain of 50% or more is required, it becomes "50% flow stress≦shear adhesion force". Furthermore, according to experiments by the present inventors, when the tensile strain is 30% or more, the workability becomes good, so the strength when the tensile strain is 30% is adopted as the strength F of the copper foil composite as follows.

FIG. 1 is a graph experimentally showing the relationship between f ₁ and (F×T), and the values of f ₁ and (F×T) in the following Examples and Comparative Examples are plotted. (F×T) is the force applied to the copper foil composite at a tensile strain of 30%. If it is regarded as the minimum shear bond strength required to improve workability, f ₁ and If the absolute value of (F×T) is the same, the two will have a visible correlation in slope 1.

However, in Fig. 1, f ₁ and (F×T) are not all correlated in the same way, and the correlation coefficients of f ₁ with respect to (F×T) for comparative examples with poor workability (that is, Say, through the origin of Figure 1, the slope of f with respect to (F _× T) is smaller, and the 180° peel bond strength is correspondingly poorer. On the other hand, the inclination of each example is larger than that of each comparative example, and the inclination of Example 18 (an example that breaks at just 30% strain) with the smallest inclination is 1/33, so this value is regarded as The correlation coefficient between the minimum shear bond strength necessary to improve workability and the 180° peel bond strength. That is, the shear adhesive strength is considered to be 33 times the 180° peel adhesive strength f ₁ .

It should be noted that, in the case of Comparative Example 3, the slope of Figure 1 exceeds 1/33, but the following formula 1: (f ₃ ×t ₃ )/(f ₂ ×t ₂ ) is less than 1, so the processing sexual deterioration.

180° peel adhesion is force per unit width (N/mm).

When the copper foil composite has a three-layer structure and there are a plurality of bonding surfaces, the value with the lowest 180° peeling adhesive strength among the bonding surfaces is used. The reason for this is that the weakest bonded side will peel.

In addition, the adhesive strength can be improved by changing the pressure or temperature conditions when laminating the copper foil and the resin layer. It is preferable to simultaneously increase the pressure and temperature during lamination within the range not to damage 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 side of the resin layer, hereinafter appropriately referred to as "adhesive surface") by chromate treatment, etc. , or roughen the surface of the copper foil, or set a Ni layer or Ni alloy layer on the surface of the copper foil, or set a Cr oxide layer after coating the surface of the copper foil with Ni. In addition, as described below, a Ni layer or a Ni alloy layer is formed on the copper foil surface (non-adhesive surface) on the opposite side to the resin layer, and at the same time as the formation of the Ni layer or Ni alloy layer on the non-adhesive surface, In the same step, a Ni layer or a Ni alloy layer is also formed on the bonding surface. Furthermore, a Cr oxide layer may be formed after forming a Ni layer or a Ni alloy layer on the bonding surface.

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

The thickness of the Ni layer or Ni alloy layer on the bonding 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 decrease.

In addition, the adhesive strength can be improved by changing the pressure or temperature conditions when laminating the copper foil and the resin layer. It is preferable to simultaneously increase the pressure and temperature during lamination within the range not to damage the resin layer.

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

In addition, the Ni alloy layer is preferably an alloy that contains 20 wt% or more of Ni, and further contains a total of 5 wt% or more of one or more of Zn, Sn, Co, Cr, Mn, V, P, B, W, Mo, and Fe. , and the rest are unavoidable impurities.

In addition, at least one of the above-mentioned Ni layer or Ni alloy layer may be formed on the non-adhesive surface of the copper foil. In addition, when both the Ni layer and the Ni alloy layer are formed on the non-adhesive surface of the copper foil, it may be the order of the Ni layer/Ni alloy layer from the outermost surface, or may be the Ni alloy layer from the outermost surface. /Ni layer sequence. In addition, "total thickness" refers to 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") in the claims will be described. Since the copper foil composite is laminated with copper foil and resin layers having the same width (size), Equation 1 represents the ratio of forces applied to the copper foil and the resin layer constituting the copper foil composite. Therefore, a 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 was not broken indicates good processability.

On the other hand, if (f ₃ ×t ₃ )/(f ₂ ×t ₂ )<1, more force is applied to the copper foil side, so there will be no "transmission of the deformation behavior of the resin layer to the copper foil". foil and make the copper foil also deform in the same way as the resin” above.

Here, f ₂ and f ₃ need only be the stress under the same amount of strain after plastic deformation, but considering the tensile fracture strain of the copper foil and the strain at the beginning of plastic deformation of the resin layer (such as PET film), set is the stress of 4% of the tensile strain. It should be noted that f ₂ and f ₃ (and f ₁ ) are all MD (Machine Direction, longitudinal) values.

<33f ₁ /(F×T)>

Next, the meaning of (33f ₁ /(F×T)) (hereinafter referred to as “Formula 2”) in the claims will be described. As mentioned above, since the shear adhesive strength, which directly represents the minimum adhesive strength between the copper foil and the resin layer necessary for improving processability, is about 33 times the 180° peel adhesive strength f ₁ , 33f ₁ Indicates the minimum adhesive strength necessary to improve the processability of the copper foil and the resin layer. On the other hand, since (F×T) is a force applied to the copper foil composite, Equation 2 becomes the ratio of the adhesive strength between the copper foil and the resin layer and the tensile resistance of the copper foil composite. Furthermore, when the copper foil composite is stretched, shear stress is applied to the interface between the copper foil and the resin layer through the copper foil to be partially deformed and the resin to be stretched and uniformly strained. Therefore, if the adhesive strength is lower than the shear stress, the copper and the resin layer will be separated, and the deformation behavior of the resin layer will not be transmitted to the copper foil, so that the ductility of the copper foil will not be improved.

That is, when the ratio of Formula 2 is less than 1, the adhesive strength becomes weaker than the force applied to the copper foil composite, the copper foil and the resin become 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 deformation behavior of the resin layer can be transmitted to the copper foil without peeling the copper and the resin layer, and the ductility of the copper foil can be improved. It should be noted that the higher the ratio in Formula 2, the better, but it is generally difficult to achieve a value of 10 or more, so it is preferable to set the upper limit of Formula 2 to 10.

It should be noted that the greater the 33f ₁ /(F×T), the better the processability, but the tensile strain 1 of the resin layer is not proportional to 33f ₁ /(F×T). This is caused by the size of (f ₃ ×t ₃ )/(f ₂ ×t ₂ ), the ductility of copper foil and resin layer alone, but as long as 33f ₁ /(F×T)≥1 , (f ₃ × t ₃ )/(f ₂ × t ₂ ) ≥ 1 combination of copper foil and resin layer can obtain a complex with required processability.

Here, the reason why the strength when the tensile strain is 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, workability becomes good. In addition, the reason for this is that the tensile test of the copper foil composite was carried out, and as a result, up to the tensile strain of 30%, there was a large difference in the flow stress due to the strain, and after 30%, the tensile strain did not change. There will be a larger difference in flow stress (work cures slightly, but the slope of the curve becomes considerably smaller).

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

As described above, the copper foil composite of the present invention prevents cracking of the copper foil even when subjected to severe (complex) deformation different from uniaxial bending such as press working, and has excellent workability. In particular, the present invention is suitable for three-dimensional forming such as press working. By stereoforming the copper foil composite, the copper foil composite can be made into a complex shape, or the strength of the copper foil composite can be improved. For example, the copper foil composite itself can be used as a frame for various power circuits, Thereby, reduction of the number of parts and cost can be aimed at.

<1/L>

The ratio l/L of the tensile fracture strain l of the copper foil composite to the tensile fracture strain L of the resin layer alone is preferably 0.7-1.

Generally, the tensile breaking strain of the resin layer is overwhelmingly higher than that of the copper foil, and similarly, the breaking strain of the resin layer alone is overwhelmingly higher than that 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 fracture strain of the copper foil composite can be increased to that of the resin layer. 70-100% of the tensile breaking strain of the layer monomer. Moreover, when ratio l/L is 0.7 or more, press formability will improve further.

It should be noted that the tensile fracture strain 1 of the copper foil composite is the tensile fracture strain during the tensile test, and it is set to this value when the resin layer and the copper foil are broken at the same time, and is set to the copper foil when the copper foil is broken first. Value at foil break.

<Tg of resin layer>

Usually, the strength of the resin layer decreases or the adhesive force decreases at high temperature, so it becomes difficult to satisfy (f ₃ ×t ₃ )/(f ₂ ×t ₂ )≥1, or 1≤33f ₁ /(F× T). For example, at a temperature above the Tg (glass transition temperature) of the resin layer, it may become difficult to maintain the strength or adhesive force of the resin layer, and at a temperature lower than Tg, it may become easier to maintain the strength of the resin layer. or adhesion tendency. That is, if the temperature is lower than the Tg (glass transition temperature) of the resin layer (for example, 5°C to 215°C), the copper foil composite will easily satisfy (f ₃ ×t ₃ )/(f ₂ × t ₂ ) ≥ 1, and 1 ≤ 33f ₁ /(F×T). It should be noted that even at a temperature lower than Tg, it is considered that there is a tendency that the strength or adhesive force of the resin layer becomes smaller when the temperature is higher, and it becomes difficult to satisfy the formulas 1 and 2 (see Example 19 below). -twenty one).

Furthermore, it was found that, when Expressions 1 and 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.) lower than the Tg of the resin layer. If the ductility of the copper foil composite can be maintained even at a relatively high temperature (for example, 40° C. to 215° C.) lower than the Tg of the resin layer, it will exhibit excellent processability in methods such as warm pressing. In addition, for the resin layer, the formability is better when the temperature is higher. In addition, since warm pressing is performed to maintain the shape after pressing (in order not to return to the original shape due to elastic deformation), it is also preferable from this point of view that even at a relatively high temperature lower than the Tg of the resin layer ( For example, 40°C to 215°C), the ductility of the copper foil composite can also be maintained.

In addition, when a copper foil composite body contains an adhesive bond layer and a resin layer, Tg of the layer with the lowest Tg (glass transition temperature) is used.

[Example]

＜Manufacture of copper foil composites＞

The ingot made of ductile copper is hot-rolled, and the oxide is removed by cutting the surface, followed by repeated cold-rolling, annealing, and pickling to make it thinner to the thickness t ₂ (mm) in Table 1, and finally annealing. Processability is ensured, and copper foil is obtained by performing antirust treatment with benzotriazole. In order to make the copper foil have a uniform structure in the width direction, the tension during cold rolling and the rolling and shrinking conditions in the width direction of the rolled material are made uniform. In the subsequent annealing, the temperature is controlled using a plurality of heaters so that the temperature distribution becomes uniform in the width direction, and the temperature of copper is measured and controlled.

Furthermore, after performing the surface treatment shown in Table 1 on both sides of the obtained copper foil, respectively, using the resin film (resin layer) shown in Table 1, a temperature of (Tg of the resin layer + 50° C.) or higher was applied by vacuum application. The resin film was laminated under pressure (pressing pressure: 200 N/cm ² ), and a copper foil composite with the layer structure shown in Table 1 was produced. In Example 5, a copper foil composite was produced by laminating copper foil and a resin film using an adhesive.

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

In addition, the Ni (alloy) layer of the thickness shown in Table 1 was formed in one surface (surface which does not adhere|attach to a resin layer) of copper foil. The surface treatment shown in Table 1 was performed on the opposite surface of the copper foil (the surface to be bonded to the resin layer). The conditions of the surface treatment are as follows.

Chromate treatment: use a chromate bath (K ₂ Cr ₂ O ₇ : 0.5-5g/L) to conduct electrolytic treatment at a current density of 1-10A/dm ² . The deposition amount of the Cr oxide layer by the chromate treatment was set at 35 μg/dm ² .

Coated Ni + chromate treatment: use Ni plating bath (Ni ion concentration: 1-30g/L Watt bath), after plating Ni at a plating solution temperature of 25-60°C and a current density of 0.5-10A/ ^dm2 , and Chromate treatment was performed in the same manner as above. The thickness of coating Ni was set to 0.010 μm.

Coarsening treatment: use treatment liquid (Cu: 10-25g/L; H2SO4: 20-100g/L), conduct electrolysis treatment at a temperature of 20-40°C, a current density of 30-70A/dm ² , and an electrolysis time of 1-5 seconds . Thereafter, use a Ni-Co plating solution (Co ion concentration: 5-20g/L; Ni ion concentration: 5-20g/L; pH: 1.0-4.0) at a temperature of 25-60°C and a current density of 0.5- 10A/dm ² for Ni-Co plating.

In addition, the formation of the Ni (alloy) layer on the non-adhesive surface of copper foil was performed under the same conditions as the said coating Ni, respectively.

In addition, in the case of Example 24, a Ni—Zn layer having a thickness of 2.5 μm was formed on the non-adhesive surface of the copper foil. On the other hand, after forming a Ni-Zn layer also on the bonding surface of copper foil, it carried out chromate treatment similarly to the above. The Ni-Zn layer is formed by using a Ni-Zn plating bath (Ni ion concentration: 15-20g/L; Zn ion concentration: 10-20g/L), plating solution temperature 50°C, and current density 4.0A/ ^dm2 Formed by plating. As a result of analyzing the Ni—Zn layer, the alloy composition was Ni:Zn=75:25 (wt%).

In the case of Example 25, a Ni—P layer with a thickness of 2.5 μm was formed on the non-adhesive surface of the copper foil. On the other hand, after forming the Ni-P layer also on the bonding surface of copper foil, it carried out chromate treatment similarly to the above. The Ni-P layer is plated by using a Ni-P plating bath (Ni ion concentration: 15-20g/L; P concentration: 5g/L), plating solution temperature 50-60°C, and current density 4A/ ^dm2 And formed. As a result of analyzing the Ni—P layer, the alloy composition was Ni:P=95:5 (wt%).

In the case of Example 26, a Ni—Sn layer with a thickness of 2.5 μm was formed on the non-adhesive surface of the copper foil. On the other hand, after forming the Ni—Sn layer also on the bonding surface of the copper foil, the chromate treatment was performed in the same manner as above. The Ni-Sn layer is formed by using a Ni-Sn plating bath (Ni ion concentration: 15-20g/L; Sn ion concentration: 10-15g/L), plating solution temperature 45°C, and current density 4.0A/ ^dm2 Formed by plating. As a result of analyzing the Ni—Sn layer, 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 on the non-adhesive surface of the copper foil was changed to 0.3 μm. As a result of analyzing the Ni—Sn layer, 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 this order on the non-adhesive surface of the copper foil, and then heat treatment was performed at 180° C. for 7 hours in a nitrogen atmosphere. On the other hand, after forming a Ni layer on the bonding surface of copper foil, it carried out chromate treatment similarly to the above. The Ni layer was formed by using a Ni sulfate Ni bath (Ni ion concentration: 25 g/L) at 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) at a plating solution temperature of 45° C. and a current density of 8 A/dm ² . The secondary electron image of the plating cross-section on the non-adhesive side of the copper foil was observed by SEM, and it was found that two layers were formed, and the layer on the outermost layer was analyzed, and the result was Ni:Sn=30:70 (wt%) , based on the results, it was judged to be a Ni-Sn layer. Analysis of the layer on the base material side revealed that Sn was 5 wt% or less and the remainder was Ni. Based on the results, it was judged to be a Ni layer. Each layer has a thickness of 0.1 μm (a total thickness of 0.2 μm).

The deposition amount of the Cr oxide layer, the thickness of the Ni layer and the Ni alloy layer were calculated by mixing HNO ₃ (2% by weight) and HCl (5% by weight) on a 100mm×100mm copper foil on which these layers were formed. was dissolved in the solution, and the concentration of each metal in the solution was quantified by an ICP emission spectrometer (manufactured by SII NanoTechnology Inc., model SFC-3100) to calculate. The measurement was performed five times for each sample, and the average value thereof was defined as the adhesion amount (thickness).

It should be noted that the thicknesses of the Ni layer and the Ni alloy layer were converted using known specific gravity based on the mass of each metal quantified by the above method.

＜Tensile test＞

A plurality of short strip-shaped tensile test pieces with a width of 12.7 mm were produced from the copper foil composite. Regarding the tensile test of the copper foil and the resin film, the copper foil alone and the resin film alone before lamination were made into a short strip of 12.7 mm.

Then, a tensile test was performed in a direction parallel to the rolling direction of the copper foil in accordance with JIS-Z2241 using a tensile tester. Table 1 shows the test temperature during the tensile test.

＜180°peel test＞

A 180° peel test was performed to measure the 180° peel adhesive strength f ₁ . First, a plurality of strip-shaped peeling test pieces with a width of 12.7 mm were produced from the copper foil composite. The copper foil surface of the test piece was fixed to the SUS board, and the resin layer was peeled off in the 180° direction. Regarding the example in which copper foil exists on both sides of the resin layer, after removing the copper foil on one side, the copper foil side on the opposite side was fixed to the SUS board, and the resin layer was peeled off in the 180° direction. Other conditions are based on JIS-C5016.

It should be noted that the copper foil layer is peeled off according to the JIS standard, and the reason for peeling off the resin layer in the examples is to reduce the influence of the thickness and rigidity of the copper foil.

＜Evaluation of processability＞

Processability was evaluated using the cupping test apparatus 10 shown in FIG. 2 . The cupping test device 10 includes a base 4 and a puncher 2. The base 4 has a truncated conical inclined surface. The front end of the truncated truncated cone becomes thinner from top to bottom. In addition, a circular hole with a diameter of 15 mm and a depth of 7 mm communicated with the lower side of the truncated cone. On the other hand, the puncher 2 is formed as a hemispherical cylinder with a diameter of 14 mm at the tip, and the hemispherical portion at the tip of the puncher 2 can be inserted into the circular hole of the truncated cone.

It should be noted that the connection portion between the tapered front end of the truncated cone and the circular hole on the lower side of the truncated cone has a circular arc with a radius (r)=3 mm.

Next, the copper foil composite was punched into a disk-shaped test piece 20 with a diameter of 30 mm, and the copper foil composite was placed on the inclined surface of the truncated cone of the base 4, and the puncher 2 was pressed down from above the test piece 20. And insert it towards the round hole of the base 4. Thereby, the test piece 20 was formed in the shape of a conical cup.

In addition, when the resin layer exists only in one side of a copper foil composite body, it mounts on the base 4 so that a resin layer may face upward. In addition, when there are resin layers on both surfaces of the copper foil composite, the resin layer bonded to the M surface is placed on the base 4 facing upward. When both surfaces of a copper foil composite body are Cu, it does not matter which surface faces upward.

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

◎: The copper foil is not cracked and the copper foil has no wrinkles

○: The copper foil is not cracked, but the copper foil is slightly wrinkled

╳: The copper foil was broken.

＜Evaluation of corrosion resistance＞

Under the pressure of 98±10KPa, on the surface of the copper foil laminate that is not laminated with the resin layer, the salt water adjusted to the concentration of sodium chloride 5±1wt%, pH=6.5～7.2 and the temperature of 35±2°C is subjected to 460°C. After 1 hour of spraying, the appearance was visually observed. Moreover, the presence or absence of a copper foil component was analyzed on this surface by XPS. the

◎: Discoloration not confirmed, copper foil not exposed (copper foil components were not detected from the surface)

○: Discoloration such as white blur is confirmed, and copper foil is not exposed (copper foil components are not detected from the surface)

╳: Black discoloration due to oxidation of copper foil, green discoloration due to rust, and exposure of copper foil were confirmed (copper foil components were detected from the surface).

＜Evaluation of the stability of electrical contact performance＞

After each test piece was air-heated at 180° C. for 1000 hours, the contact resistance was measured on the copper foil surface on which the resin layer was not laminated. The measurement was performed by the four-terminal method using an electric contact simulator CRS-1 manufactured by Yamazaki Seiki Co., Ltd. Probe: gold probe, contact load: 40g, sliding speed: 1mm/min, sliding distance: 1mm. the

○: Contact resistance lower than 10mΩ

╳: The contact resistance is 10mΩ or more.

The obtained results are shown in Table 1 and Table 2. In addition, the test temperature of Table 1 shows the temperature which evaluated F, _f1 , _f2 , _f3 , and workability.

[Table 1]

[Table 2]

It can be seen from Table 1 and Table 2 that, in the case of each embodiment, (f ₃ ×t ₃ )/(f ₂ ×t ₂ )≥1 and 1≤33f ₁ /(F×T) are simultaneously satisfied, so that An example with excellent workability. In addition, in the case of each Example, the electrical contact performance and corrosion resistance were also excellent.

In addition, when Example 15 and Example 19 using the copper foil laminated body of the same structure are compared, it can be seen that compared with Example 19, the tensile test was performed at room temperature (about 25 degreeC) and measured In Example 15 such as F, the value of (f ₃ ×t ₃ )/(f ₂ ×t ₂ ) was larger, and in Example 19, the resin layer became weak (f ₃ decreased) due to the rise in test temperature.

On the other hand, in the case of Comparative Example 1 in which the resin film was laminated without surface-treating the copper foil, the adhesive strength decreased, the value of 33f ₁ /(F×T) was less than 1, and the processability deteriorated.

In the case of Comparative Examples 2 and 4 in which the lamination pressure was reduced to 100 N/cm ² , the adhesive strength was lowered, the value of 33f ₁ /(F×T) was less than 1, and the processability deteriorated.

In the case of Comparative Example 3 in which the thickness of the resin film was thinned, 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 the workability deteriorating.

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

Claims (6)

1. Copper foil composite body, which is a copper foil composite body formed by laminating copper foil and resin layers, characterized in that: When the thickness of the copper foil is set as t ₂ (mm), the stress of the copper foil at 4% tensile strain is set as f ₂ (MPa), and the thickness of the resin layer is set as t ₃ ( mm), when the stress of the resin layer at a tensile strain of 4% is set as f ₃ (MPa), formula 1 is satisfied: (f ₃ ×t ₃ )/(f ₂ ×t ₂ )≥1; In addition, when the 180° peel bonding strength between the copper foil and the resin layer is set as f ₁ (N/mm), the strength of the copper foil composite at a tensile strain of 30% is set as F (MPa ), when the thickness of the copper foil composite is set as T (mm), formula 2 is satisfied: 1≤33f ₁ /(F×T); A Ni layer and/or a Ni alloy layer having a total thickness of 0.001 to 5.0 μm is formed on the surface of the copper foil on which the resin layer is not laminated. 2. The copper foil composite according to claim 1, wherein the total thickness of the Ni layer and/or Ni alloy layer is 0.001 to 0.50 μm. 3. The copper foil composite according to claim 1 or 2, wherein the formulas 1 and 2 hold at a temperature lower than the glass transition temperature of the resin layer. 4. The copper foil composite according to any one of claims 1 to 3, wherein the tensile fracture strain l of the copper foil composite is equal to the tensile fracture strain L of the resin layer monomer The ratio l/L is 0.7-1. 5. A molded body obtained by processing the copper foil composite according to any one of claims 1 to 4. The manufacturing method of a molded object which processes the copper foil composite body as described in any one of Claims 1-4.