A flexible bright nickel-plated copper foil having surface micropores and a method for producing the same

Abstract

The present application relates to the technical field of metal surface treatment, in particular to a surface microporous flexible bright nickel-plated copper foil and a preparation method thereof, the preparation method comprising the following steps: providing a copper foil; sequentially plating microporous copper, microporous low-stress nickel and smooth nickel on both sides of the copper foil to obtain a surface microporous flexible bright nickel-plated copper foil; wherein the double-sided roughness Rz of the surface microporous flexible bright nickel-plated copper foil is 1.5-2.5 microns, the brightness value is 10-500, and the elongation rate is >10%. The surface microporous flexible bright nickel-plated copper foil obtained by plating copper and nickel for multiple times and optimizing the composition of the plating solution has soft properties, good brightness, a microporous surface, strong bonding force with a release film, an insulating layer and a conductive adhesive layer, so that the electromagnetic shielding adhesive tape prepared therefrom has superior electromagnetic shielding performance and extremely high use stability, and can be well applied to complex spaces.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal surface treatment, in particular to a surface microporous flexible bright nickel-plated copper foil and a preparation method thereof. BACKGROUND

[0002] With the continuous development of electronic products towards multi-function and high integration, a large number of high-power electronic components are integrated in increasingly narrow device spaces, which makes the problem of electromagnetic interference that different components bear during device operation more and more serious. In addition, due to the precision of electronic components, their tolerance limit to external electromagnetic signals is also continuously reduced. To ensure that these electronic components sensitive to electromagnetic signals can operate normally, they must be protected from the interference of electromagnetic radiation generated by the external environment and adjacent devices. At present, some conductive cloth, conductive adhesive tape, conductive rubber, metal spring, etc. can achieve shielding effect of electromagnetic radiation to different degrees. Among them, electromagnetic shielding adhesive tape has become the most widely used product in shielding electromagnetic radiation due to its good shielding effect, light weight, flexible use and wide application range.

[0003] The electromagnetic shielding adhesive tape is usually made by coating a conductive adhesive tape with a shielding enhancer material and an adhesive, and then covering it with an insulating layer and a composite release film. Among them, the conductive base tape as the main substrate can be pure metal foil (nickel foil, copper foil, etc.), composite metal foil and non-metal conductive adhesive film, etc.

[0004] Metal nickel has good shielding efficiency for low-frequency and high-frequency magnetic fields; and metal copper has good electrical conductivity and is often used as an electrical shielding material. Nickel-plated copper foil has both the magnetic shielding efficiency of nickel and the electrical shielding efficiency of copper, and also has high chemical stability, so it has a wide application in the field of electromagnetic shielding and is often used as a conductive base tape for electromagnetic shielding adhesive tape.

[0005] However, the surface roughness of traditional nickel-plated copper foil is high. The highly rough surface not only has low appearance brightness and is not beautiful enough, but also is not tight enough when combined with the release film and the insulating layer and conductive adhesive layer of the adhesive tape, which can easily cause the nickel-plated copper foil and the release film / insulating layer and conductive adhesive layer to separate due to small peeling strength, resulting in damage to the adhesive tape. In addition, the hardness of the traditional nickel-plated copper foil is significantly improved after nickel plating, and the elongation is greatly reduced, resulting in large rigidity of the nickel-plated copper foil. When the adhesive tape made of the nickel-plated copper foil is pasted on a complex shape, the nickel-plated copper foil is resistant to deformation due to its rigidity, which can cause the adhesive tape to be warped and peeled off from the surface of the adhered device, resulting in weakened or even failed shielding effect.

[0006] Therefore, it is necessary to develop a flexible nickel-plated copper foil with a microporous surface to improve the bonding force between the nickel-plated copper foil and the release film, insulating layer and conductive adhesive layer, and at the same time, the nickel-plated copper foil has high flexibility, so that the electromagnetic shielding adhesive tape can be well applied to complex spaces. SUMMARY

[0007] In order to overcome the above defects of the prior art or improve the prior art, the present application provides a surface microporous flexible bright nickel-plated copper foil and a preparation method thereof, the bright nickel-plated copper foil is prepared by first plating a microporous copper layer on both surfaces of a copper foil, then plating a microporous low-stress nickel layer, and finally plating a smooth nickel layer, so that the surface microporous flexible bright nickel-plated copper foil has a double-surface roughness Rz of 1.5-2.5 μm, a brightness value of 10-500, an elongation rate of >10%, a strong bonding force with a release film, an insulating layer and a conductive adhesive layer, a peeling strength of 3-10 N / m after being attached to the release film, and a peeling strength of 50-200 N / m after being combined with the insulating layer, so that the electromagnetic shielding adhesive tape prepared therefrom has superior electromagnetic shielding performance and extremely high use stability, and can be well applied to complex spaces.

[0008] In order to achieve the above-mentioned purpose, the present application provides a preparation method of a surface microporous flexible bright nickel-plated copper foil, comprising the following steps:

[0009] (1) providing a copper foil;

[0010] (2) plating microporous copper: using a microporous copper plating process to plate a microporous copper layer on the upper and lower surfaces of the copper foil to obtain a microporous copper-plated copper foil;

[0011] (3) plating microporous low-stress nickel: plating a microporous low-stress nickel layer on the upper and lower surfaces of the microporous copper-plated copper foil to obtain a microporous low-stress nickel copper foil;

[0012] (4) plating smooth nickel: plating a smooth nickel layer on the upper and lower surfaces of the microporous low-stress nickel copper foil to obtain a surface microporous flexible bright nickel-plated copper foil;

[0013] The double-surface roughness Rz of the surface microporous flexible bright nickel-plated copper foil is 1.5-2.5 μm, the brightness value is 10-500, the elongation rate is >10%, the peeling strength after being attached to the release film is 3-10 N / m, and the peeling strength after being combined with the insulating layer is 50-200 N / m.

[0014] The surface of the traditional nickel-plated copper foil is rough, and the highly rough surface is not only not beautiful in appearance, but also not tightly combined with the release film and the insulating layer and the conductive adhesive layer of the adhesive tape when being attached, which can easily cause the separation of the nickel-plated copper foil and the release film, the insulating layer and the conductive adhesive layer due to the small bonding strength, and damage the adhesive tape. The present application uses the microporous copper plating process on both sides of the flexible copper foil with a relatively flat surface to plate a layer of microporous copper plating layer, which can enhance the bonding of the nickel-plated copper foil and the release film, the insulating layer and the conductive adhesive layer; then a microporous low-stress nickel layer is plated on the surface of the microporous copper plating layer to refine the micropore size of the copper foil surface plating layer, enhance the bonding force of the microporous plating layer and improve the chemical stability of the copper foil, while avoiding the increase of the hardness and rigidity of the copper foil caused by nickel plating; finally, a smooth nickel layer is plated on the surface of the microporous low-stress nickel layer to prevent the microporous low-stress nickel layer from falling off and cracking during use under complex conditions, and further enhance the magnetic shielding effect of the nickel-plated copper foil and the use stability under complex conditions such as high temperature, high heat and high humidity. The final surface microporous flexible bright nickel-plated copper foil has the properties of softness, good brightness, microporous surface, high adhesion to the release film and the insulating layer of the adhesive tape, and excellent electromagnetic shielding performance and use stability in complex spaces.

[0015] Further, in the step (1) of the above technical solution, the copper foil is a flexible electrolytic copper foil or a rolled copper foil, the double-sided roughness Rz of which is 0.7-2.5 μm, the brightness value is 10-500, and the elongation rate is >10%.

[0016] Further, in the step (2) of the above technical solution, the microporous copper plating process is as follows: the copper foil is placed in a plating solution with a temperature of 15-55℃, and the current density is 3-25 A / dm 2 , and the plating is performed for 2-10 s; wherein the plating solution is composed of 10-55 g / L Cu 2 + , 80-140 g / L H2SO4, 0.2-1.4 g / L first type of additive and 0.01-0.8 g / L second type of additive.

[0017] Further, in the above technical solution, the first type of additive is composed of three or more kinds of metal ions of the third, fourth and eighth subgroups, and at least one kind of metal ion of each of the third, fourth and eighth subgroups; preferably Ti, Ce, Pr, Tb and Fe, Ni which are easy to change valence. The first type of additive in the present application is mainly used to inhibit the dendritic growth of copper grains, avoid the loose and slender growth of copper grains, increase the uniformity, and improve the bonding force of the nickel-plated copper foil and the insulating layer.

[0018] Further, in the technical scheme, the second type of additive consists of one or more of metal or non-metal acid root ions of the fifth sub-group, the sixth sub-group and the fifth main group; preferably, the acid root ions of V, W, Mo and Sb; when the first type of additive is used in combination with the second type of additive, the addition ratio of the first type of additive should be 60wt.%-85wt.% (calculated based on the metal, metal acid root and non-metal acid root ions). The second type of additive in the application is used to promote the cluster growth of copper grains, reduce the roughness and further improve the uniformity, enhance the bonding between the plated nickel copper foil and the insulating layer, maintain the brightness of the plated nickel copper foil, increase the copper grain uniformity and foil surface brightness value. Meanwhile, by controlling the addition ratio of the first type of additive and the second type of additive, the Rz index, brightness, appearance uniformity and bonding strength with the adhesive tape release film and the insulating layer of the copper foil can be effectively controlled.

[0019] Further, in the technical scheme, the specific process for plating the microporous low-stress nickel layer in step (3) is as follows: the copper foil is placed in a plating solution with a temperature of 20-55℃, and the current density is 20-100A / dm 2 The plating is performed for 5-30s, and the plated copper foil is obtained; wherein the plating solution consists of 5-40g / L nickel salt A, 15-40g / L H3BO3, 100-300g / L conductive salt A and 5-20g / L cationic surfactant. By plating the microporous low-stress nickel layer, the micro-pore size of the plated layer on the surface of the copper foil can be refined, the bonding force of the microporous plated layer can be enhanced, and the chemical stability of the copper foil can be improved, while avoiding the increase in the hardness and rigidity of the copper foil caused by nickel plating.

[0020] Further, in the technical scheme, the nickel salt A is one or more of NiSO4, NiCl2 and Ni(NO3)2; the conductive salt A is one or more of the chlorides or sulfates or nitrates or acetates of sodium, potassium, ammonium and magnesium; and the cationic surfactant is any one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecylammonium acetate, sodium dodecylsulfonate and other alkyl ammonium salts and alkyl sulfonates.

[0021] Further, in the technical scheme, the specific process for plating the smooth nickel layer in step (4) is as follows: the copper foil is placed in a plating solution with a temperature of 20-55℃, and the current density is 10-35A / dm 2 The plating is performed for 5-20s, and the plated copper foil is obtained; wherein the plating solution consists of 35-80g / L nickel salt B, 30-40g / L H3BO3, 150-250g / L conductive salt B and 0.5-1g / L brightener sodium saccharin. By plating the smooth nickel layer, the peeling and cracking of the microporous low-stress nickel layer during use under complex conditions can be prevented, the magnetic shielding effect of the plated nickel copper foil can be enhanced, and the use stability of the plated nickel copper foil under complex conditions such as high temperature, high heat and high humidity can be improved.

[0022] Further, in the above technical solution, the nickel salt B is one or more of NiSO4, NiCl2, Ni(NO3)2, and nickel sulfamate, wherein the Ni provided by NiCl2 2+ No more than 10%; the conductive salt B is one or more of sodium, potassium, ammonium, and magnesium sulfate and acetate.

[0023] The application also provides a surface microporous flexible bright nickel-plated copper foil, which is prepared by the above preparation method.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] The application adopts the microporous copper plating process on both surfaces of the copper foil, coats a microporous plating layer, then coats a microporous low-stress nickel layer on the surface of the microporous copper plating layer, and finally coats a smooth nickel layer on the surface of the microporous low-stress nickel layer, while optimizing the proportion of each plating solution, so that the surface microporous flexible bright nickel-plated copper foil has the following properties: the double-surface roughness Rz is 1.5-2.5 μm, the brightness value is 10-500, the elongation rate is >10%, the peeling strength after being attached to a release film is 3-10 N / m, the peeling strength after being combined with an insulating layer is 50-200 N / m, the properties are soft, the brightness is good, the surface is microporous, the adhesion to the insulating layer of the adhesive tape is high, the electromagnetic shielding performance is superior, and the use stability is extremely high, the copper foil can be well applied to complex spaces without opening and peeling, and the appearance is bright silver white, effectively solving the problems of the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 FIG. 1 is a surface micro scanning electron microscope image (10 μm) of the copper foil after microporous copper plating in Example 1 of the application;

[0027] Figure 2 FIG. 5 is a surface micro scanning electron microscope image (10 μm) of the surface microporous flexible bright nickel-plated copper foil in Example 5 of the application;

[0028] Figure 3 FIG. 8 is a surface micro scanning electron microscope image (10 μm) of the surface microporous flexible bright nickel-plated copper foil in Example 8 of the application;

[0029] Figure 4 FIG. 4 is a surface micro scanning electron microscope image (10 μm) of the copper foil after microporous copper plating in Comparative Example 1 of the application;

[0030] Figure 5 FIG. 7 is a surface micro scanning electron microscope image (10 μm) of the nickel-plated copper foil in Comparative Example 3 of the application. DETAILED DESCRIPTION

[0031] The experimental methods in the following examples are all conventional methods unless otherwise specified. The raw materials involved in the following examples are all commercially available unless otherwise specified.

[0032] The above technical features of the present application and the technical features described in detail below (such as the examples) can be combined with each other to form new or preferred technical solutions.

[0033] The copper foils in this embodiment are of the same model and batch.

[0034] The present application aims to provide a preparation method of a surface microporous flexible bright nickel-plated copper foil, comprising the following steps:

[0035] (1) providing a copper foil, which can be a flexible electrolytic copper foil or a rolled copper foil with a relatively flat surface, with a double-sided roughness Rz of 0.7-2.5 μm and a brightness value of 10-500 and an elongation rate of >10%.

[0036] (2) microporous copper plating: microporous copper plating is performed on both sides of the copper foil, i.e. a microporous plating layer is plated on the flat surface of the copper foil to enhance the bonding of the nickel-plated copper foil with the release film, the insulating layer and the conductive adhesive layer; wherein the microporous copper plating process comprises: a plating solution composed of 10-55 g / L Cu 2+ , 80-140 g / L H2SO4 and 0.2-1.4 g / L of a first additive and 0.01-0.8 g / L of a second additive, a plating solution temperature of 15-55℃, a current density of 3-25 A / dm 2 , and a plating time of 2-10 s.

[0037] Specifically, the first additive is used to inhibit the dendritic growth of copper grains and is composed of three or more of metal ions of the third, fourth and eighth subgroups, and at least one metal ion of each of the third, fourth and eighth subgroups; preferably Ti, Ce, Pr, Tb and Fe, Ni which are easy to change valence; the second additive is used to promote the cluster growth of copper grains and is composed of one or two or three of metal acid radical ions / non-metal acid radical ions of the fifth, sixth and fifth main groups; preferably acid radical ions of V, W, Mo, Sb. When the first additive and the second additive are used in combination, the addition ratio of the first additive should account for 60wt.%-85wt.% of the total amount of the two (calculated based on metal, metal acid radical and non-metal acid radical ions). When the ratio is too low, the copper grains grow too high, the copper foil has high roughness and low brightness value; when the ratio is too high, the copper grains grow unevenly on the surface, the bonding with the release film, the insulating layer and the conductive adhesive layer is unstable, and the appearance uniformity is poor.

[0038] (3) Micro-porous low-stress nickel plating: the micro-porous low-stress nickel plating layer can refine the micro-porous size of the copper foil surface plating layer, enhance the adhesion of the micro-porous plating layer, and improve the chemical stability of the copper foil, while avoiding the increase of the hardness and rigidity of the copper foil caused by nickel plating.

[0039] The specific process of the micro-porous low-stress nickel plating layer is as follows: the plating solution is composed of 5-40 g / L Ni 2+ , 15-40 g / L H3BO3, 100-300 g / L conductive salt A, and 5-20 g / L cationic surfactant, the plating solution temperature is 20-55℃, the current density is 20-100 A / dm 2 , and the electroplating time is 5-30 s.

[0040] Specifically, the nickel salt A (Ni 2+ ) can be one or more of NiSO4, NiCl2, and Ni(NO3)2; the conductive salt A can be one or more of sodium, potassium, ammonium, and magnesium chlorides or sulfates or nitrates or acetates; and the cationic surfactant can be one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecylammonium acetate, alkyl ammonium salts such as sodium dodecyl sulfonate, and alkyl sulfonates.

[0041] (4) Smooth nickel plating: the smooth nickel plating layer can effectively prevent the micro-porous low-stress nickel layer from falling off and cracking during use under complex conditions, and enhance the magnetic shielding effect of the nickel-plated copper foil and the use stability under complex conditions such as high temperature, high heat, and high humidity. The specific process of the smooth nickel plating layer is as follows: the plating solution is composed of 35-80 g / L Ni 2+ , 30-40 g / L H3BO3, 150-250 g / L conductive salt B, and 0.5-1 g / L brightener sodium saccharin, the plating solution temperature is 20-55℃, the current density is 10-35 A / dm 2 , and the electroplating time is 5-20 s.

[0042] Specifically, the nickel salt B (Ni 2+ ) can be one or more of NiSO4, NiCl2, Ni(NO3)2, and nickel sulfamate, wherein the Ni 2+ provided by NiCl2 should not exceed 10%; and the conductive salt B can be one or more of sodium, potassium, ammonium, and magnesium sulfates and acetates.

[0043] The application will be further described in detail below with reference to specific examples:

[0044] Specifically, the nickel salt A (Ni 2- ) can be one or more of NiSO4, NiCl2, and Ni(NO3)2; the conductive salt A can be one or more of sodium, potassium, ammonium, and magnesium chlorides or sulfates or nitrates or acetates; and the cationic surfactant can be one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecylammonium acetate, alkyl ammonium salts such as sodium dodecyl sulfonate, and alkyl sulfonates. - ; the SbO3 - can be NaSbO3 or KSbO3; and the WO4 - can be Na2WO4, K2WO4, or (NH4)2WO4.2- Na2WO4, K2WO4, (NH4)2WO4.

[0045] Example 1: Microporous copper plating

[0046] Take a copper foil, placed in 45 g / L Cu 2+ , 110 g / L H2SO4, the first kind of additives 0.20 g / L Ce 4+ , 0.37 g / L Ni 2+ , 0.07 g / L Ti 4+ , the second kind of additives 0.25 g / L MoO4 2- , 0.13 g / L SbO3 - The plating solution temperature is 30℃, the current density is 8A / dm 2 , and the plating time is 7s.

[0047] The copper plated surface is observed by scanning electron microscope, as shown in Figure 1 , wherein the double-sided roughness Rz is 1.50μm, the brightness value is 191, the elongation rate is 17.05%, the peeling strength after being combined with the release film is 1.4N / m, and the peeling strength after being combined with the insulation layer is 357N / m.

[0048] Example 2: Microporous copper plating

[0049] Take a copper foil, placed in 45 g / L Cu 2+ , 110 g / L H2SO4, the first kind of additives 0.13 g / L Ce 4+ , 0.51 g / L Ni 2+ , 0.08 g / L Ti 4+ , the second kind of additives 0.19 g / L MoO4 2- , 0.13 g / L SbO3 - The plating solution temperature is 30℃, the current density is 8A / dm 2 , and the plating time is 7s.

[0050] , wherein the double-sided roughness Rz of the copper plated surface is 1.43μm, the brightness value is 210, the elongation rate is 16.9%, the peeling strength after being combined with the release film is 1.43N / m, and the peeling strength after being combined with the insulation layer is 346N / m.

[0051] Example 3: Microporous copper plating

[0052] Take a copper foil, placed in 19 g / L Cu 2+ , 127 g / L H2SO4, the first kind of additives 0.15 g / L Tb 4+ , 0.44 g / L Fe 2+0.29g / L Ni 2+ 0.04g / L WO4 2- 0.19g / L SbO3 - The plating solution temperature is 45℃, the current density is 17A / dm 2 , and the plating time is 5s.

[0053] The roughness of the copper-plated double surface is Rz=1.56μm, the brightness value is 177, the elongation rate is 17.25%, the peeling strength after being combined with the release film is 1.36N / m, and the peeling strength after being combined with the insulating layer is 274N / m.

[0054] Example 4: microporous copper plating

[0055] A copper foil is placed in a plating solution containing 20g / L Cu 2+ , 125g / L H2SO4, 0.18g / L Ce 4+ , 0.4g / L Ni 2+ , 0.09g / L Ti 2+ , 0.03g / L WO4 2- , 0.22g / L SbO3 - , and the plating solution temperature is 45℃, the current density is 17A / dm 2 , and the plating time is 5s.

[0056] The roughness of the copper-plated double surface is Rz=1.61μm, the brightness value is 172, the elongation rate is 17.3%, the peeling strength after being combined with the release film is 1.36N / m, and the peeling strength after being combined with the insulating layer is 295N / m.

[0057] Example 5

[0058] A method for preparing a flexible bright nickel-plated copper foil with microporous surface, comprising the following steps:

[0059] (1) providing a copper foil;

[0060] (2) microporous copper plating: using a microporous copper plating process to plate a microporous copper layer on the upper and lower surfaces of the copper foil to obtain a microporous copper-plated copper foil; wherein the plating solution contains 45g / L Cu 2+ , 112g / L H2SO4, 0.18g / L Ce 4+ , 0.4g / L Ni 2+ , 0.09g / L Ti 4+ , 0.03g / L WO4 2- , 0.22g / L SbO3 -, the plating solution temperature is 30 DEG C, the current density is 6 A / dm 2 , and the plating time is 7 s.

[0061] (3) Plating microporous low-stress nickel: a layer of microporous low-stress nickel is plated on the upper and lower surfaces of the microporous copper-plated copper foil to obtain a microporous low-stress nickel-copper foil; wherein the plating solution is 15 g / L Ni 2+ (30wt% nickel sulfamate + 70wt% NiSO4), 37 g / L H3BO3, 150 g / L K2SO4, 100 g / L (NH4)2SO4, 10 g / L cetyltrimethylammonium bromide, the plating solution temperature is 40 DEG C, the current density is 35 A / dm 2 , and the plating time is 15 s.

[0062] (4) Plating smooth nickel: a layer of smooth nickel is plated on the upper and lower surfaces of the microporous low-stress nickel-copper foil to obtain a surface microporous flexible bright nickel-plated copper foil; wherein the plating solution is 45 g / L Ni 2+ (30wt% nickel sulfamate + 70wt% NiSO4), 38 g / L H3BO3, 150 g / L MgSO4, 0.5 g / L sodium saccharin, the plating solution temperature is 30 DEG C, the current density is 20 A / dm 2 , and the plating time is 15 s.

[0063] The copper-plated surface is observed by a scanning electron microscope, as shown in Figure 2 , wherein the double-sided roughness Rz is 1.72 μm, the brightness value is 405, the elongation rate is 13.2%, the peeling strength after being attached to a release film is 5.4 N / m, and the peeling strength after being combined with an insulating layer is 143 N / m.

[0064] Example 6

[0065] A preparation method of a surface microporous flexible bright nickel-plated copper foil, comprising the following steps:

[0066] (1) providing a copper foil;

[0067] (2) plating microporous copper: a layer of microporous copper is plated on the upper and lower surfaces of the copper foil by a microporous copper plating process to obtain a microporous copper-plated copper foil; wherein the plating solution is 45 g / L Cu 2+ , 110 g / L H2SO4, the first additive is 0.18 g / L Ce 4+ , 0.38 g / L Ni 2+ , the second additive is 0.08 g / L Ti 4+ , 0.24 g / L MoO4 2- , 0.13 g / L SbO3 - , the plating solution temperature is 30 DEG C, the current density is 6 A / dm 2 , and the plating time is 7 s.

[0068] (3) plating microporous low-stress nickel: a layer of microporous low-stress nickel is plated on the upper and lower surfaces of the microporous copper foil, to obtain a microporous low-stress nickel copper foil; wherein the plating solution is 35 g / L Ni 2+ (Ni(NO3)2), 37 g / L H3BO3, 150 g / L K2SO4, 100 g / L (NH4)2SO4, 10 g / L cetyltrimethylammonium bromide, the plating solution temperature is 40°C, the current density is 35 A / dm 2 , and the electroplating time is 15 s;

[0069] (4) plating smooth nickel: a layer of smooth nickel is plated on the upper and lower surfaces of the microporous low-stress nickel copper foil, to obtain a surface microporous flexible bright nickel plated copper foil; wherein the plating solution is 45 g / L Ni 2+ (amino sulfonic acid nickel), 38 g / L H3BO3, 150 g / L MgSO4, 0.5 g / L sodium saccharin, the plating solution temperature is 30°C, the current density is 20 A / dm 2 , and the electroplating time is 15 s.

[0070] The copper foil is plated on both sides with a roughness Rz of 1.3 μm, a brightness value of 467, an elongation of 12.7%, a peeling strength after being attached to a release film of 9.27 N / m, and a peeling strength after being combined with an insulating layer of 89 N / m.

[0071] Example 7

[0072] A preparation method of a surface microporous flexible bright nickel plated copper foil, comprising the following steps:

[0073] (1) providing a copper foil;

[0074] (2) plating microporous copper: a layer of microporous copper is plated on the upper and lower surfaces of the copper foil by a microporous copper plating process, to obtain a microporous copper plated copper foil; wherein the plating solution is 46 g / L Cu 2+ , 110 g / L H2SO4, 0.17 g / L Ce 4+ , 0.42 g / L Ni 2+ , 0.09 g / L Ti 4+ , 0.2 g / L MoO4 2- , 0.12 g / L SbO3 - , the plating solution temperature is 30°C, the current density is 6 A / dm 2 , and the electroplating time is 7 s;

[0075] (3) plating microporous low-stress nickel: a layer of microporous low-stress nickel is plated on the upper and lower surfaces of the microporous copper foil, to obtain a microporous low-stress nickel copper foil; wherein the plating solution is 35 g / L Ni 2+(NiSO4), 38 g / L H3BO3, 120 g / L K2SO4, 100 g / L (NH4)2SO4, 50 g / L ammonium acetate, 15 g / L sodium dodecyl sulfonate, the plating solution temperature is 45°C, the current density is 80 A / dm 2 , and the plating time is 24 s.

[0076] (4) Smooth nickel plating: a smooth nickel layer is plated on the upper and lower surfaces of the microporous low-stress nickel copper foil to obtain a surface microporous flexible bright nickel-plated copper foil; wherein the plating solution is 70 g / L Ni 2+ (50wt%NiSO4+50wt%Ni(NO3)2), 38 g / L H3BO3, 200 g / L (NH4)2SO4, 1 g / L sodium saccharin, the plating solution temperature is 45°C, the current density is 30 A / dm 2 , and the plating time is 9 s.

[0077] The copper-plated double-sided roughness Rz is 1.52 μm, the brightness value is 446, the elongation rate is 10.34%, the peeling strength after being attached to a release film is 7.62 N / m, and the peeling strength after being combined with an insulating layer is 122 N / m.

[0078] Example 8

[0079] A preparation method of a surface microporous flexible bright nickel-plated copper foil, comprising the following steps:

[0080] (1) providing a copper foil;

[0081] (2) microporous copper plating: a microporous copper layer is plated on the upper and lower surfaces of the copper foil by using a microporous copper plating process to obtain a microporous copper-plated copper foil; wherein the plating solution is 19 g / L Cu 2+ , 120 g / L H2SO4, the first type of additive is 0.11 g / L Tb 4+ , 0.45 g / L Fe 2+ , 0.23 g / L Ni 2+ , the second type of additive is 0.03 g / L WO4 2- , 0.2 g / L SbO3 - , the plating solution temperature is 45°C, the current density is 20 A / dm 2 , and the plating time is 5 s.

[0082] (3) microporous low-stress nickel plating: a microporous low-stress nickel layer is plated on the upper and lower surfaces of the microporous copper-plated copper foil to obtain a microporous low-stress nickel copper foil; wherein the plating solution is 15 g / L Ni 2+(80wt% NiSO4+20wt% NiCl2), 36g / L H3BO3, 150g / L K2SO4, 100g / L (NH4)2SO4, 10g / L cetyl trimethyl ammonium bromide, plating solution temperature is 35℃, current density is 35A / dm 2 , and plating time is 15s.

[0083] (4) plating smooth nickel: a layer of smooth nickel layer is plated on the upper and lower surfaces of the microporous low-stress nickel copper foil to obtain a surface microporous flexible bright nickel plated copper foil; wherein the plating solution is 70g / L Ni 2+ (30wt% nickel sulfamate + 70wt% NiSO4), 38g / L H3BO3, 200g / L (NH4)2SO4, 1g / L sodium saccharin, plating solution temperature is 45℃, current density is 30A / dm 2 , and plating time is 9s.

[0084] The copper plated surface is observed by a scanning electron microscope, as shown in Figure 3 , wherein the double-sided roughness Rz is 1.73μm, the brightness value is 390, the elongation rate is 13.41%, the peeling strength after being combined with a release film is 5.3N / m, and the peeling strength after being combined with an insulating layer is 154N / m.

[0085] Example 9

[0086] A preparation method of a surface microporous flexible bright nickel plated copper foil, comprising the following steps:

[0087] (1) providing a copper foil;

[0088] (2) plating microporous copper: a layer of microporous copper layer is plated on the upper and lower surfaces of the copper foil by using a microporous copper plating process to obtain a microporous copper plated copper foil; wherein the plating solution is 20g / L Cu 2+ , 123g / L H2SO4, 0.12g / L Tb 4+ of the first type of additive, 0.47g / L Fe 2+ of the first type of additive, 0.25g / L Ni 2+ of the first type of additive, 0.03g / L WO4 2- of the second type of additive, 0.21g / L SbO3 - of the second type of additive, plating solution temperature is 45℃, current density is 20A / dm 2 , and plating time is 5s.

[0089] (3) plating microporous low-stress nickel: a layer of microporous low-stress nickel layer is plated on the upper and lower surfaces of the microporous copper plated copper foil to obtain a microporous low-stress nickel copper foil; wherein the plating solution is 36g / L Ni 2+(70wt% NiSO4+30wt% Ni(NO3)2), 34g / L H3BO3, 150g / L K2SO4, 100g / L (NH4)2SO4, 10g / L cetyl trimethyl ammonium bromide, plating solution temperature is 35℃, current density is 35A / dm 2 , and plating time is 15s.

[0090] (4) Plating smooth nickel: a layer of smooth nickel layer is plated on the upper and lower surfaces of the microporous low-stress nickel copper foil to obtain a surface microporous flexible bright nickel plated copper foil; wherein the plating solution is 70g / L Ni 2+ (NiSO4), 36g / L H3BO3, 100g / L K2SO4, 100g / L (NH4)2SO4, 1g / L sodium saccharin, plating solution temperature is 45℃, current density is 30A / dm 2 , and plating time is 9s.

[0091] Wherein, the copper plated double-sided roughness Rz is 1.68μm, the brightness value is 422, the elongation is 11.55%, the peeling strength after being combined with the release film is 6.95N / m, and the peeling strength after being combined with the insulating layer is 117N / m.

[0092] Example 10

[0093] A preparation method of a surface microporous flexible bright nickel plated copper foil, comprising the following steps:

[0094] (1) providing a copper foil;

[0095] (2) plating microporous copper: a layer of microporous copper layer is plated on the upper and lower surfaces of the copper foil by using a microporous copper plating process to obtain a microporous copper plated copper foil; wherein the plating solution is 20g / L Cu 2+ , 119g / L H2SO4, the first type of additive is 0.11g / L Tb 4+ , 0.44g / L Fe 2+ , 0.27g / L Ni 2+ , the second type of additive is 0.02g / L WO4 2- , 0.21g / L SbO3 - , the plating solution temperature is 45℃, the current density is 20A / dm 2 , and the plating time is 5s.

[0096] (3) plating microporous low-stress nickel: a layer of microporous low-stress nickel layer is plated on the upper and lower surfaces of the microporous copper plated copper foil to obtain a microporous low-stress nickel copper foil; wherein the plating solution is 34g / L Ni 2+(NiSO4), 37 g / L H3BO3, 200 g / L (NH4)2SO4, 100 g / L ammonium acetate, 15 g / L sodium dodecylsulfate, plating solution temperature is 45°C, current density is 80 A / dm 2 , and plating time is 24 s.

[0097] (4) Smooth nickel plating: a smooth nickel layer is plated on the upper and lower surfaces of the microporous low-stress nickel-copper foil to obtain a microporous flexible bright nickel-plated copper foil; wherein the plating solution is 45 g / L Ni 2+ (95.6wt%Ni(NO3)2+4.4wt%NiCl2), 38 g / L H3BO3, 150 g / L MgSO4, 0.5 g / L sodium saccharin, plating solution temperature is 30°C, current density is 20 A / dm 2 , and plating time is 15 s.

[0098] Wherein, the double-sided roughness Rz of the plated copper is 1.91 μm, the brightness value is 367, the elongation rate is 10.7%, the peeling strength after being attached with a release film is 3.42 N / m, and the peeling strength after being combined with an insulating layer is 179 N / m.

[0099] Comparative Example 1: Microporous copper plating

[0100] Take a copper foil and place it in a plating solution of 47 g / L Cu 2+ , 107 g / L H2SO4, the first type of additive 0.15 g / L Ce 4+ , 0.33 g / L Ni 2+ , 0.06 g / L Ti 4+ , the plating solution temperature is 30°C, the current density is 8 A / dm 2 , and the plating time is 7 s.

[0101] Observe the plated copper surface by scanning electron microscopy, as shown in Figure 4 , wherein the double-sided roughness Rz is 1.94 μm, the brightness value is 23, the elongation rate is 17.1%, the peeling strength after being attached with a release film is 0.17 N / m, and the peeling strength after being combined with an insulating layer is 876 N / m.

[0102] Comparative Example 2: Microporous copper plating

[0103] Take a copper foil and place it in a plating solution of 17 g / L Cu 2+ , 123 g / L H2SO4, the second type of additive 0.04 g / L WO4 2- , 0.03 g / L SbO3 - , the plating solution temperature is 30°C, the current density is 17 A / dm 2 , and the plating time is 5 s.

[0104] The double-sided roughness Rz = 1.75 μm, the gloss value is 92, the elongation is 16.7%, the peel strength after bonding with the release film is 0.35 N / m, and the peel strength after bonding with the insulating layer is 652 N / m.

[0105] Comparative Example 3

[0106] A method for preparing a flexible, bright nickel-plated copper foil with microporous surface includes the following steps:

[0107] (1) Provide a copper foil;

[0108] (2) Microporous copper plating: A microporous copper plating process is used to plate a layer of microporous copper on both the upper and lower surfaces of the copper foil to obtain microporous copper-plated copper foil; wherein the plating solution is 46 g / L Cu 2+ 111 g / L H2SO4, Class I additive 0.16 g / L Ce 4+ 0.4 g / L Ni 2+ The second type of additive is 0.09 g / L Ti. 4+ 0.21 g / L MoO4 2- 0.13 g / L SbO3 - The plating bath temperature is 30℃, and the current density is 6A / dm³. 2 The electroplating time is 7 seconds;

[0109] (3) Smoothing nickel plating: A smooth nickel layer is plated on the upper and lower surfaces of the microporous copper foil to obtain nickel-plated copper foil; wherein, the plating solution is 65g / L Ni 2+ (30wt% nickel sulfamate + 70wt% NiSO4), 36g / L H3BO3, 200g / L (NH4)2SO4, 0.5g / L sodium saccharin, plating bath temperature 30℃, current density 20A / dm³ 2 The electroplating time is 15 seconds.

[0110] Observe the copper-plated surface using a scanning electron microscope, such as Figure 5 As shown, the double-sided roughness Rz = 1.32 μm, the gloss value is 533, the elongation is 6.3%, the peel strength after bonding with the release film is 14.6 N / m, and the peel strength after bonding with the insulating layer is 32.1 N / m.

[0111] Comparative Example 4

[0112] A method for preparing a flexible, bright nickel-plated copper foil with microporous surface includes the following steps:

[0113] (1) Provide a copper foil;

[0114] (2) Micro-porous copper plating: a micro-porous copper layer is plated on the upper and lower surfaces of the copper foil by micro-porous copper plating process to obtain a micro-porous copper plated copper foil; wherein the plating solution is 20 g / L Cu 2+ , 120 g / L H2SO4, 0.13 g / L Tb of the first additive 4+ , 0.45 g / L Fe 2+ , 0.25 g / L Ni 2+ , 0.02 g / L WO4 2- of the second additive, 0.22 g / L SbO3 - , the plating solution temperature is 45°C, the current density is 20 A / dm 2 , and the plating time is 5 s.

[0115] (3) Micro-porous low-stress nickel plating: a micro-porous low-stress nickel layer is plated on the upper and lower surfaces of the micro-porous copper plated copper foil to obtain a nickel plated copper foil; wherein the plating solution is 37 g / L Ni 2+ (NiSO4), 36 g / L H3BO3, 200 g / L (NH4)2SO4, 100 g / L ammonium acetate, the plating solution temperature is 45°C, the current density is 80 A / dm 2 , and the plating time is 24 s.

[0116] The double-sided roughness of the copper plating is 2.12 μm, the brightness value is 86, the elongation rate is 15.93%, the peeling strength after being attached to the release film is 0.23 N / m, and the peeling strength after being combined with the insulating layer is 1052 N / m.

[0117] Conclusion:

[0118] As can be seen from Examples 1-4, the micro-porous copper plating process can obtain a micro-porous copper plating layer with low double-sided roughness and high brightness value, and the micro-porous copper plating layer has good bonding force with the insulating layer, but the bonding force with the release film is poor; as can be seen from Examples 5-10, the micro-porous copper plating process combined with the micro-porous low-stress nickel plating and the smooth nickel plating process, the elongation rate of the nickel plated copper foil is still >10%, the micro-porous surface and the low roughness make the peeling strength of the nickel plated copper foil after being attached to the release film be between 3-10 N / m, and the peeling strength after being combined with the insulating layer be between 50-200 N / m, which improves the comprehensive use stability, the high brightness value makes the appearance of the nickel plated copper foil be uniform and bright silver white, and the nickel plated copper foil has high aesthetic property.

[0119] From the comparative example 1-2 and the comparative example 1, the example 3-4 and the comparative example 2, it can be seen that in the comparative example 1, only the first type of additive is used, the brightness value of the surface of the copper foil is low, the appearance is poor, and the peeling strength after being attached with the release film is too low, and the peeling strength with the insulation layer is too high, and the bonding strength with the release film and the insulation layer cannot be considered; in the comparative example 2, only the second type of additive is used, and similar problems exist. It is shown that only when the first type of additive and the second type of additive are used at the same time and the ratio of the two is controlled, the uniformity of the copper grain surface growth can be ensured, the roughness is reduced, the brightness value is improved, and the stability of the bonding with the release film and the insulation layer is considered at the same time.

[0120] From the comparative example 5-6 and the comparative example 3, it can be seen that in the comparative example 3, the microporous low-stress nickel is not plated, and the smooth nickel is directly plated, the surface roughness is not greatly affected, but the brightness value is too high, the elongation rate is low, the release film peeling strength is high, and the insulation layer peeling strength is too low, and the bonding strength with the release film and the insulation layer cannot be considered; from the comparative example 7-8 and the comparative example 4, it can be seen that in the comparative example 4, the production of the nickel-plated copper foil is completed after plating the microporous low-stress nickel, although the elongation rate is high and the softness is excellent, the roughness is greatly improved, the brightness value is reduced, the appearance is dull and densely covered with bright and dark spots, a large number of black spots are produced in a short time under high humidity and high heat conditions, especially after being attached with the release film, the peeling strength is low, and the insulation layer peeling strength is too high, and the bonding strength with the release film and the insulation layer cannot be considered. It is shown that after the copper foil is plated with copper, the microporous low-stress nickel and the smooth nickel are combined to consider the bonding strength with the release film and the insulation layer and improve the appearance.

[0121] In summary, the surface microporous flexible bright nickel-plated copper foil obtained by once plating copper, twice plating nickel and optimizing the composition of the plating solution has soft properties, good brightness, a microporous surface, strong bonding force with the release film, the insulation layer and the conductive adhesive layer, so that the electromagnetic shielding adhesive tape produced has excellent electromagnetic shielding performance and high use stability, and can be well applied to complex spaces.

[0122] Finally, it needs to be emphasized that the above description is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a surface-microporous flexible bright nickel-plated copper foil, characterized by, It comprises the following steps: (1) providing a copper foil; (2) plating microporous copper: using a microporous copper plating process, a microporous copper layer is plated on the upper and lower surfaces of the copper foil to obtain a microporous copper-plated copper foil; The micro-porous copper plating process is: putting copper foil into plating solution with temperature of 15-55℃, under current density of 3-25A / dm 2 The plating solution is prepared by adding 10-55g / L Cu 2+ , 80-140g / L H2SO4, 0.2-1.4g / L first type additive and 0.01-0.8g / L second type additive; the first type additive is composed of multiple kinds of metal ions of the third, fourth and eighth sub-groups, and at least one kind of metal ion of the third, fourth and eighth sub-groups; the second type additive is composed of one or more kinds of metalate ions or non-metalate ions of the fifth, sixth and fifth main groups; when the first type additive is used in combination with the second type additive, the adding proportion of the first type additive is 60wt.%-85wt.% in terms of metal, metalate and non-metalate ions. (3) plating microporous low-stress nickel: a microporous low-stress nickel layer is plated on the upper and lower surfaces of the microporous copper-plated copper foil to obtain a microporous low-stress nickel copper foil; (4) plating smooth nickel: a smooth nickel layer is plated on the upper and lower surfaces of the microporous low-stress nickel copper foil to obtain a surface microporous flexible bright nickel-plated copper foil; The surface microporous flexible bright nickel-plated copper foil has a double-sided roughness Rz of 1.5-2.5 μm, a brightness value of 10-500, and an elongation of >10%.

2. The method of claim 1, wherein the flexible bright nickel-plated copper foil is micro- porous. In step (1), the copper foil is a flexible electrolytic copper foil or a rolled copper foil, which has a double-sided roughness Rz of 0.7-2.5 μm, a brightness value of 10-500, and an elongation of >10%.

3. The method of claim 1, wherein the flexible bright nickel plated copper foil is surface microporous. In step (3), the specific process for plating the microporous low-stress nickel layer is as follows: the copper foil is placed in a plating solution at a temperature of 20-55℃, and a current density of 20-100 A / dm 2 is obtained after electroplating for 5-30 s; wherein the plating solution is composed of 5-40 g / L nickel salt A, 15-40 g / L H3BO3, 100-300 g / L conductive salt A, and 5-20 g / L cationic surfactant.

4. The method for preparing a surface-microporous flexible bright nickel-plated copper foil according to claim 3, characterized in that, The nickel salt A is one or more of NiSO4, NiCl2, and Ni(NO3)2; the conductive salt A is one or more of sodium, potassium, ammonium, magnesium chloride or sulfate or nitrate or acetate; and the cationic surfactant is any one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecylammonium acetate, dodecylammonium sodium alkyl sulfonate, and alkyl sulfonate.

5. The method of claim 1, wherein the flexible bright nickel plated copper foil is surface microporous. In step (4), the specific process for plating the smooth nickel layer is as follows: the copper foil is placed in a plating solution at a temperature of 20-55℃, and a current density of 10-35 A / dm 2 is obtained after electroplating for 5-20 s; wherein the plating solution is composed of 35-80 g / L nickel salt B, 30-40 g / L H3BO3, 150-250 g / L conductive salt B, and 0.5-1 g / L brightener sodium saccharin.

6. The method of claim 5, wherein the flexible bright nickel plated copper foil is surface microporous. The nickel salt B is one or more of NiSO4, NiCl2, Ni(NO3)2, nickel sulfamate, wherein Ni is provided by NiCl2 2+ not more than 10%; the electrically conductive salt B is one or more of sodium, potassium, ammonium, magnesium sulfate and acetate.

7. A surface-microporous flexible bright nickel-plated copper foil, characterized by, The surface microporous flexible bright nickel-plated copper foil is prepared by the method of any one of claims 1-6.

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