Electrolytic copper foil and electrolytic copper foil surface treatment process

Abstract

The invention discloses an electrolytic copper foil and an electrolytic copper foil surface treatment process, and relates to the field of electrolytic copper foil preparation. The process conditions of ashing I are as follows: the temperature of an ashing vinasse solution is 20-35 DEG C, the concentration of zinc ions is 3.0-5.0 g / L, the concentration of nickel ions is 1.5-2.5 g / L, the concentration of potassium pyrophosphate is 100-120 g / L, the pH value is 9.5-10.5, the liquid inlet flow is 3-8 m < 3 > / h, the current density of a liquid inlet end is 3-5 A / dm < 2 >, and the current density of a liquid outlet end is 2-3 A / dm < 2 >; the process conditions of ashing II are as follows: the temperature of the ashing vinasse solution is 20-35 DEG C, the zinc ion concentration is 4-6g / L, the nickel ion concentration is 1.0-1.5 g / L, the potassium pyrophosphate concentration is 100-120g / L, the pH value is 9.0-9.5, the liquid inlet flow is 3-8m < 3 > / h, the current density at the liquid inlet end is 3-5A / dm < 2 >, and the current density at the liquid outlet end is 2-3A / dm < 2 >; through the design, the anti-stripping strength of the electrolytic copper foil is improved.

Description

Technical Field

[0001] The present application relates to the field of electrolytic copper foil preparation, and in particular to an electrolytic copper foil and a surface treatment process for electrolytic copper foil. Background Art

[0002] With the acceleration of the global informatization process, the electronics industry has developed rapidly and achieved remarkable achievements. As the bearing foundation and cornerstone in electronic circuits, copper clad laminates (CCLs) must meet the characteristics of small dielectric constant, low dielectric loss, low roughness of the copper foil surface, high density, high integration, and high thermal conductivity. Copper foil, as a key material for preparing copper clad laminates, has two production methods: rolled copper foil and electrolytic copper foil. Among them, electrolytic copper foil is widely used in copper clad laminates due to its low process cost, simple operation, high production efficiency, and good safety. However, whether it is electrolytic copper foil or rolled copper foil, it needs to be surface-treated before being made into copper clad laminates, and the quality of the surface treatment process directly affects the quality of the copper foil.

[0003] In the production of electrolytic copper foil, its process flow is generally: electrolyte preparation, electrolytic raw foil production, surface treatment, and slitting and packaging. Among them, surface treatment refers to electroplating treatment on the surface of the copper foil to improve various performance indicators of the raw foil through copper plating, zinc plating, and chromium plating, such as anti-peeling performance indicators, anti-oxidation performance indicators, etc.

[0004] Currently, the ashing layer of the ultra-thick medium-profile electrolytic copper foil prepared by the existing copper foil production process is uneven. After passivation, a layer of silane coupling agent is coated on the surface of the copper foil. The anti-oxidation performance of the treated copper foil is poor, the peel strength is low, and over time, the anti-peel strength of the copper foil decays severely, which cannot meet the requirements of high-end electronic products. Summary of the Invention

[0005] The purpose of the present application is to provide an electrolytic copper foil and a surface treatment process for electrolytic copper foil to improve the anti-peel strength of the electrolytic copper foil.

[0006] The present application discloses a surface treatment process for electrolytic copper foil for preparing electrolytic copper foil, including the following processes: copper foil unrolling, pickling, roughening I, curing I, roughening II, curing II, roughening III, curing III, water washing I, ashing I, water washing II, ashing II, water washing III, passivation, water washing IV, water washing V, spraying silane, drying, testing, and winding;

[0007] Among them, the process conditions of the ashing I are: the temperature of the ashing tank solution is 20°C - 35°C, the zinc ion concentration is 3.0 - 5.0 g / L, the nickel ion concentration is 1.5 - 2.5 g / L, the potassium pyrophosphate concentration is 100 - 120 g / L, the pH value is 9.5 - 10.5, the inlet liquid flow rate is 3 - 8 m 3 / h, and the current density at the inlet liquid end is 3 - 5 A / dm2 The current density at the liquid outlet end is 2 - 3 A / dm 2 ;

[0008] The process conditions for the second ashing are as follows: the temperature of the ashing tank solution is 20°C - 35°C, the zinc ion concentration is 4 - 6 g / L, the nickel ion concentration is 1.0 - 1.5 g / L, the potassium pyrophosphate concentration is 100 - 120 g / L, the pH value is 9.0 - 9.5, the inlet liquid flow rate is 3 - 8 m 3 / h, the current density at the inlet liquid end is 3 - 5 A / dm 2 and the current density at the liquid outlet end is 2 - 3 A / dm 2 .

[0009] Optionally, the thickness of the electrolytic copper foil is 70 μm - 105 μm; the process conditions for the first roughening, the second roughening, and the third roughening are as follows: the solution configuration in the first roughening tank, the second roughening tank, and the third roughening tank are all composed of a copper ion concentration of 9 - 15 g / L, a sulfuric acid concentration of 150 - 180 g / L, an inlet liquid flow rate of 5 - 8 m 3 / h, the current density at the inlet liquid end is 10 - 45 A / dm 2 and the current density at the liquid outlet end is 10 - 30 A / dm 2 and the solution temperature is 20°C - 30°C;

[0010] The process conditions for the first curing, the second curing, and the third curing are as follows: the solution configuration in the first curing tank, the second curing tank, and the third curing tank are all composed of: a copper ion concentration of 40 - 60 g / L, a sulfuric acid concentration of 80 - 100 g / L, an inlet liquid flow rate of 5 - 10 m 3 / h, the current density at the inlet liquid end is 10 - 50 A / dm 2 and the current density at the liquid outlet end is 10 - 35 A / dm 2 and the solution temperature is 30°C - 50°C;

[0011] The process conditions for the first water washing, the second water washing, the third water washing, the fourth water washing, and the fifth water washing are as follows: the solution configuration in the first water washing tank, the second water washing tank, the third water washing tank, the fourth water washing tank, and the fifth water washing tank are all deionized water, the inlet liquid flow rate is 3 - 5 m 3 / h, the pH value is 5 - 7.0, and the water washing temperature is 20°C - 25°C;

[0012] The process conditions for the passivation are as follows: the temperature of the passivation tank solution is 20°C - 35°C, the concentration of hexavalent chromium ions is 2.0 - 3.0 g / L, the pH value is 10.0 - 11.0, the inlet liquid flow rate is 3 - 8 m 3 / h, the current density at the inlet liquid end is 3 - 5 A / dm 2 and the current density at the liquid outlet end is 2 - 3 A / dm2 ;

[0013] The process of spraying silane is as follows: spraying a silane coupling agent with a concentration of 1-3 wt% on the surface of the copper foil, at a temperature of 20°C - 35°C, and a spraying flow rate of 1500 - 2000 ml / min.

[0014] Optionally, the process conditions for both Ashing I and Ashing II are: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.0 g / L, the nickel ion concentration is 2.0 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 ;

[0015] The process of spraying silane is as follows: spraying a 2 wt% γ-aminopropyltriethoxysilane solution on the surface of the copper foil, at a temperature of 25°C, and a spraying flow rate of 2000 ml / min.

[0016] Optionally, the process conditions for Ashing I are: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.5 g / L, the nickel ion concentration is 1.6 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.5, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 ;

[0017] The process conditions for Ashing II are: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 5.5 g / L, the nickel ion concentration is 1.2 g / L, the potassium pyrophosphate concentration is 100 g / L, the pH value is 9.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 ;

[0018] The process conditions for spraying silane are: coating a 2 wt% 3-glycidoxypropyltrimethoxysilane solution on the surface of the copper foil, at a temperature of 25°C, and a spraying flow rate of 2000 ml / min.

[0019] Optionally, the process conditions for Ashing I are: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.5 g / L, the nickel ion concentration is 1.6 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.5, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2, the current density at the liquid outlet end is 3 A / dm 2 ;

[0020] The process conditions for the second ashing are as follows: the temperature of the ashing tank solution is 35 °C, the zinc ion concentration is 5.5 g / L, the nickel ion concentration is 1.2 g / L, the potassium pyrophosphate concentration is 100 g / L, the pH value is 9.0, the liquid inlet flow rate is 5 m 3 / h, the current density at the liquid inlet end is 5 A / dm 2 , the current density at the liquid outlet end is 3 A / dm 2 ;

[0021] The process conditions for spraying silane are as follows: spraying a silane coupling agent with a concentration of 2 wt% on the surface of the copper foil, where the silane coupling agent refers to γ-aminopropyltriethoxysilane, the temperature is 25 °C, and the spraying flow rate is 2000 ml / min.

[0022] Optionally, the process conditions for passivation are as follows: the temperature of the passivation tank solution is 30 °C, the concentration of hexavalent chromium ions is 2.5 g / L, the pH value is 10.0, the liquid inlet flow rate is 5 m 3 / h, the current density at the liquid inlet end is 5 A / dm 2 , the current density at the liquid outlet end is 3 A / dm 2 .

[0023] Optionally, the process conditions for the first roughening, the second roughening, and the third roughening are as follows: the solution compositions in the first roughening tank, the second roughening tank, and the third roughening tank are all: the copper ion concentration is 15 g / L, the sulfuric acid concentration is 180 g / L, the liquid inlet flow rate is 5 m 3 / h, the current density at the liquid inlet end is 45 A / dm 2 , the current density at the liquid outlet end is 30 A / dm 2 , and the solution temperature is 30 °C.

[0024] Optionally, the process conditions for the first curing, the second curing, and the third curing are as follows: the solution compositions in the first curing tank, the second curing tank, and the third curing tank are all the copper ion concentration is 55 g / L, the sulfuric acid concentration is 100 g / L, the liquid inlet flow rate is 5 m 3 / h, the current density at the liquid inlet end is 50 A / dm 2 , the current density at the liquid outlet end is 35 A / dm 2 , and the solution temperature is 40 °C.

[0025] Optionally, the process conditions for the first water washing, the second water washing, the third water washing, the fourth water washing, and the fifth water washing are as follows: the solution compositions in the first water washing tank, the second water washing tank, the third water washing tank, the fourth water washing tank, and the fifth water washing tank are all deionized water, and the liquid inlet flow rate is 5 m 3 / h, pH value 7.0, and solution temperature 25°C.

[0026] Optionally, the process conditions for the detection are as follows: Cut the prepared copper foil into appropriate sizes, soak it in hydrochloric acid, and after complete dissolution, make up the solution to a 100 ml volumetric flask, and use an inductively coupled plasma emission spectrometer to detect the ions in the solution.

[0027] This application also discloses an electrolytic copper foil prepared by using the above-described surface treatment process for electrolytic copper foil.

[0028] Optionally, the thickness of the electrolytic copper foil is 70 μm to 105 μm.

[0029] Compared with the current surface treatment process for electrolytic copper foil, in this application, by adjusting the concentrations of zinc ions and nickel ions in the ashing process, the antioxidant ability of the electrolytic copper foil is improved, so that a film layer with a complex structure can be formed in the subsequent passivation process, preventing the copper foil from oxidizing and discoloring due to direct contact with air. At the same time, the heat resistance of the electrolytic copper foil is also improved, further enhancing the peel resistance of the electrolytic copper foil. Description of the Drawings

[0030] The accompanying drawings included are used to provide a further understanding of the embodiments of this application. They form a part of the specification, are used to illustrate the implementation manners of this application, and together with the written description, explain the principles of this application. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. In the drawings:

[0031] Figure 1 is a flowchart of a surface treatment process for an electrolytic copper foil provided by an embodiment of this application;

[0032] Figure 2 is the copper foil peel strength curve of different surface treatment methods;

[0033] Figure 3 is the copper foil peel attenuation curve graph of different surface treatment methods after being placed for 6 months. Detailed Embodiments

[0034] It should be understood that the terms, the specific structures and functional details disclosed here are only for describing specific embodiments, which are representative, but this application can be specifically implemented in many alternative forms and should not be construed as being limited only to the embodiments described here.

[0035] The following describes this application in detail with reference to the drawings and optional embodiments.

[0036] Figure 1 is a flowchart of a surface treatment process for electrolytic copper foil provided by an embodiment of the present application. As Figure 1 shown, the present application discloses a surface treatment process for electrolytic copper foil for preparing electrolytic copper foil, including the following processes: copper foil unrolling, pickling, roughening I, curing I, roughening II, curing II, roughening III, curing III, water washing I, ashing I, water washing II, ashing II, water washing III, passivation, water washing IV, water washing V, spraying silane, drying, testing and winding.

[0037] It should be noted that in the actual production process, the roughening process, curing process and / or water washing process can be reduced according to needs, or the roughening process, curing process and / or water washing process can be increased according to needs, which does not affect the use of the technical solutions in the present application.

[0038] The purpose of the present application is to provide a surface treatment process for improving the peel strength of ultra-thick medium-profile electrolytic copper foil. Specifically, the process conditions of the ashing I are: the temperature of the ashing tank solution is 20°C to 35°C, the zinc ion concentration is 3.0 to 5.0 g / L, the nickel ion concentration is 1.5 to 2.5 g / L, the potassium pyrophosphate concentration is 100 to 120 g / L, the pH value is 9.5 to 10.5, the inlet liquid flow rate is 3 to 8 m 3 / h, and the current density at the inlet end is 3 to 5 A / dm 2 , and the current density at the outlet end is 2 to 3 A / dm 2 .

[0039] The process conditions of the ashing II are: the temperature of the ashing tank solution is 20°C to 35°C, the zinc ion concentration is 4 to 6 g / L, the nickel ion concentration is 1.0 to 1.5 g / L, the potassium pyrophosphate concentration is 100 to 120 g / L, the pH value is 9.0 to 9.5, the inlet liquid flow rate is 3 to 8 m 3 / h, and the current density at the inlet end is 3 to 5 A / dm 2 , and the current density at the outlet end is 2 to 3 A / dm 2 .

[0040] The main functions of the ashing I and ashing II processes are to perform zinc and nickel treatment to form a zinc-nickel alloy on the surface of the copper foil, improve the high-temperature oxidation resistance of the copper foil, and enhance the heat resistance of the copper foil, which also provides a good treatment basis for the subsequent passivation process. Among them, Zn 2+ and Ni 2+ are provided by zinc sulfate and nickel sulfate respectively.

[0041] Compared with the current surface treatment process of electrolytic copper foil, in this application, by adjusting the concentration of zinc ions and nickel ions in the ashing process, the antioxidant ability of the electrolytic copper foil is improved, so that a chromium metal anti-oxidation layer with a complex structure can be formed in the subsequent passivation process, further preventing the copper foil from oxidizing and discoloring due to direct contact with air, and at the same time improving the heat resistance of the electrolytic copper foil and further enhancing the anti-peeling performance of the electrolytic copper foil.

[0042] In the embodiments of this application, the thickness of the electrolytic copper foil is 70μm - 105μm. In the field of electrolytic copper foil, copper foil with a thickness of 70μm - 100μm is of medium thickness, while copper foil with a thickness greater than 100μm belongs to ultra-thick thickness. And the profile generally refers to the surface roughness and microscopic morphology of the copper foil. Medium profile means that its surface roughness is between low profile and conventional profile. The roughness of the lamination surface (m surface) is usually Ra ≤ 4μm, 15μm ≤ Rz ≤ 20μm; the roughness of the non-lamination surface (s surface) is Ra ≤ 0.4μm, Rz ≤ 3μm.

[0043] In the embodiments of this application, in the processes of roughening I, roughening II, and roughening III: the solution compositions in the roughening I tank, roughening II tank, and roughening III tank are all copper ion concentration of 9 - 15g / L, sulfuric acid concentration of 150 - 180g / L, inlet liquid flow rate of 5 - 8m 3 / h, inlet end current density of 10 - 45A / dm 2 , outlet end current density of 10 - 30A / dm 2 , and solution temperature of 20°C - 30°C, so as to deposit a layer of dendritic cuprous oxide particles on the matte surface of the copper foil and increase the specific surface area of the matte surface.

[0044] In the processes of curing I, curing II, and curing III: the solution compositions in the curing I tank, curing II tank, and curing III tank are all copper ion concentration of 40 - 60g / L, sulfuric acid concentration of 80 - 100g / L, inlet liquid flow rate of 5 - 10m 3 / h, inlet end current density of 10 - 50A / dm 2 , outlet end current density of 10 - 35A / dm 2 , and solution temperature of 30°C - 50°C. The function is to deposit a layer of dense metallic copper in the gaps between the nodular particles of the roughened copper foil, reduce the surface roughness of the roughened layer, and improve the adhesion of the roughened layer to the copper foil.

[0045] In the passivation process: the temperature of the passivation tank solution is 20°C - 35°C, the concentration of hexavalent chromium ions is 2.0 - 3.0g / L, the pH value is 10.0 - 11.0, the inlet liquid flow rate is 3 - 8m 3 / h, and the inlet end current density is 3 - 5A / dm 2, the current density at the liquid outlet end is 2 - 3 A / dm 2 . Among them, Cr 6+ is provided by chromium trioxide.

[0046] In the processes of water washing I, water washing II, water washing III, water washing IV, and water washing V: the solution configurations in the water washing I tank, water washing II tank, water washing III tank, water washing IV tank, and water washing V tank are all deionized water, the inlet liquid flow rate is 3 - 5 m 3 / h, the pH value is 5 - 7.0, and the water washing temperature is 20°C - 25°C. That is, when the copper foil is about to enter the next section, it is washed with deionized water. The main function is to wash the electrolyte attached to the surface of the copper foil clean, prevent the cross-flow of the electrolyte between each plating tank, affect the treatment effect of the next step in the surface treatment process of the copper foil, and ensure that the surface of the copper foil is clean when entering the next section.

[0047] This application conducts five water washings, and between the passivation and silane spraying processes, through continuous water washing IV and water washing V processes, to ensure that there will be no electrolyte and ion residues on the surface of the electrolytic copper foil, and it will not affect the yield of the finished product.

[0048] In the silane spraying process, the temperature of the passivation tank solution is 20°C - 35°C, the concentration of hexavalent chromium ions is 2.0 - 3.0 g / L, the pH value is 10.0 - 11.0, the inlet liquid flow rate is 3 - 8 m 3 / h, the current density at the inlet liquid end is 3 - 5 A / dm 2 , and the current density at the liquid outlet end is 2 - 3 A / dm 2 ; among them, the main function of silane spraying is to further increase the peel strength of the copper foil.

[0049] In the drying process, the copper foil can be placed in an oven and dried at 200°C - 250°C. The main function of drying is to remove the moisture and wet and dry gases on the surface and in the pores of the copper foil, remove hydrogen and eliminate stress, increase the flexibility and ductility of the copper foil, and eliminate brittleness.

[0050] In the processes of copper foil unwinding and copper foil rewinding, the linear speeds of unwinding and rewinding can be 20 - 40 m / min.

[0051] As can be seen from the above, the formula of the present invention is simple, the cost is low, it is suitable for actual production, and has a good market prospect.

[0052] This application also combines the following two specific embodiments and corresponding comparative examples to clearly and completely describe the solution of this application.

[0053] It should be understood that the implementation cases described below are only part of the implementation cases of this application, not all of them. Based on the implementation cases in this application, all other implementation cases obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0054] Example 1:

[0055] The process conditions of the roughening I, roughening II, and roughening III are as follows: The solution compositions in the roughening I tank, roughening II tank, and roughening III tank are all: copper ion concentration is 15 g / L, sulfuric acid concentration is 180 g / L, inlet flow rate is 5 m 3 / h, inlet end current density is 45 A / dm 2 , outlet end current density is 30 A / dm 2 , and solution temperature is 30 °C;

[0056] The process conditions of the curing I, curing II, and curing III are as follows: The solution compositions in the curing I tank, curing II tank, and curing III tank are all copper ion concentration is 55 g / L, sulfuric acid concentration is 100 g / L, inlet flow rate is 5 m 3 / h, inlet end current density is 50 A / dm 2 , outlet end current density is 35 A / dm 2 , and solution temperature is 40 °C;

[0057] The process conditions of the ashing I are as follows: The temperature of the ashing tank solution is 35 °C, zinc ion concentration is 4.5 g / L, nickel ion concentration is 1.6 g / L, potassium pyrophosphate concentration is 110 g / L, pH value is 10.5, inlet flow rate is 5 m 3 / h, inlet end current density is 5 A / dm 2 , outlet end current density is 3 A / dm 2 ;

[0058] The process conditions of the ashing II are as follows: The temperature of the ashing tank solution is 35 °C, zinc ion concentration is 5.5 g / L, nickel ion concentration is 1.2 g / L, potassium pyrophosphate concentration is 100 g / L, pH value is 9.0, inlet flow rate is 5 m 3 / h, inlet end current density is 5 A / dm 2 , outlet end current density is 3 A / dm 2 ;

[0059] The process conditions of the passivation are as follows: The temperature of the passivation tank solution is 30 °C, hexavalent chromium ion concentration is 2.5 g / L, pH value is 10.0, inlet flow rate is 5 m 3 / h, inlet end current density is 5 A / dm 2, the current density at the liquid outlet end is 3 A / dm 2 ;

[0060] The process conditions of the first water wash, the second water wash, the third water wash, the fourth water wash and the fifth water wash are as follows: the solution compositions in the first water wash tank, the second water wash tank, the third water wash tank, the fourth water wash tank and the fifth water wash tank are all deionized water, the inlet flow rate is 5 m 3 / h, the pH value is 7.0, and the water wash temperature is 25°C;

[0061] The process conditions for spraying silane are as follows: a 3-glycidoxypropyltrimethoxysilane solution with a concentration of 2 wt% is coated on the surface of the copper foil, the temperature is 25°C, and the spraying flow rate is 2000 ml / min.

[0062] Example 2:

[0063] In this example, different from Example 1, the process conditions of the first ashing and the second ashing are both: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.0 g / L, the nickel ion concentration is 2.0 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.0, the inlet flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , the current density at the liquid outlet end is 3 A / dm 2 ;

[0064] The process for spraying silane is as follows: a γ-aminopropyltriethoxysilane solution with a concentration of 2 wt% is sprayed on the surface of the copper foil, the temperature is 25°C, and the spraying flow rate is 2000 ml / min.

[0065] Example 3:

[0066] In this example, different from Example 1, the process conditions of the first ashing are: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.5 g / L, the nickel ion concentration is 1.6 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.5, the inlet flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , the current density at the liquid outlet end is 3 A / dm 2 ;

[0067] The process conditions of the second ashing are: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 5.5 g / L, the nickel ion concentration is 1.2 g / L, the potassium pyrophosphate concentration is 100 g / L, the pH value is 9.0, the inlet flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , the current density at the liquid outlet end is 3 A / dm 2 ;

[0068] The process conditions for spraying silane are as follows: spraying a γ-aminopropyltriethoxysilane solution with a concentration of 2 wt% on the surface of the copper foil, at a temperature of 25°C and a spraying flow rate of 2000 ml / min.

[0069] Comparative Example 1:

[0070] The difference between Comparative Example 1 and Example 1 is that the process conditions for both Ashing I and Ashing II are as follows: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.0 g / L, the nickel ion concentration is 2.0 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 , while other processes are the same as those in Example 1.

[0071] After two rolls of 70 μm and 105 μm copper foils produced in the raw copper foil workshop are processed according to the four different surface treatment methods of Comparative Example 1 and Examples 1 - 3 respectively, the peel strength of the finished products is measured using prepregs, and the test results are shown in Table 1 below:

[0072]

[0073] Table 1

[0074] Figure 2 is the peel strength curve of copper foils with different surface treatment methods. It can be seen from Table 1 combined with Figure 2 that after optimizing the surface treatment method, the peel resistance performance of the copper foil is significantly improved, significantly higher than that of the unoptimized Comparative Example 1. And when changing the solution in the ashing tank and using an amino-type silane coupling agent simultaneously, the peel strength of the copper foil reaches the highest. The 70 μm copper foil is 3.31 N / mm in the TG140 test and 1.92 N / mm in the TG170 test. The 105 μm copper foil is 4.12 N / mm in the TG140 test and 2.21 N / mm in the TG170 test, indicating that the optimized surface treatment method can significantly improve the peel resistance performance of the copper foil.

[0075] After being placed at room temperature for 6 months, the comparison of the peel strength with time of copper foils with different surface treatment methods is shown in Table 2 below:

[0076]

[0077] Table 2

[0078] The peel strength attenuation rate of copper foils with different surface treatment methods is shown in Table 3 below:

[0079]

[0080] Table 3

[0081] Figure 3 It is the anti-peeling attenuation curve graph of copper foils with different surface treatment methods placed for 6 months. Through Figure 3 Combined with Table 2, it can be seen that the anti-peeling strength of the copper foils after treatment has decreased to varying degrees, and the attenuation degree results are shown in Table 3. It can be found from Table 3 that in the anti-peeling test of TG140, the anti-peeling attenuation values of Comparative Example 1 and the examples are not much different, but in the TG170 test, it can be seen that after replacing the amino-type silane coupling agent, the attenuation rate of the copper foil is significantly reduced, and compared with other methods, the anti-peeling attenuation degree of Example 3 is the lowest, indicating that improving the ashing section process and replacing the amino-type silane coupling agent can significantly improve the time-dependent anti-peeling performance of the copper foil, and it is more obvious in the 105μm copper foil.

[0082] The electroplating amount data of copper foils with different surface treatment methods are shown in Table 4 below:

[0083]

[0084]

[0085] The prepared copper foil is cut into a suitable size and soaked in hydrochloric acid. After complete dissolution, the solution is fixed in a 100ml volumetric flask, and an inductively coupled plasma emission spectrometer (ICP) is used to detect the ions in the solution. It can be seen from Table 4 that there is a large difference in the electroplating amounts of the left, middle, and right of the copper foil in Comparative Example 1, indicating that the ashing layer plated by the unoptimized ashing tank is uneven. After optimizing the ashing tank solution, it can be found that the electroplating amounts of the left, middle, and right of the copper foils in Examples 1 and 3 are almost the same, indicating that the optimized ashing tank can make the ashing layer of the copper foil more uniform, thereby enhancing its antioxidant performance.

[0086] It can be seen from this that by adopting the technical solution of the present application, by adjusting the concentrations of zinc ions and nickel ions in the ashing solution in the ashing process, the ashing tank solution is optimized, and the copper foils produced by the surface treatment process in the technical solution of the present application are tested, and the test results can all meet the production requirements. Moreover, for the copper foils produced by the surface treatment process in the technical solution of the present application, the attenuation degree of the anti-peeling strength is greatly reduced.

[0087] The present application also discloses an electrolytic copper foil, which is prepared by using the above-mentioned electrolytic copper foil surface treatment process.

[0088] It should be noted that the inventive concept of the present application can form a very large number of embodiments. However, due to the limited space of the application documents, it is impossible to list them all. Therefore, on the premise of non-conflict, the above-described embodiments or technical features can be arbitrarily combined to form new embodiments. After the combination of each embodiment or technical feature, the original technical effect will be enhanced.

[0089] The above content is a further detailed description of the present application in combination with specific optional implementation manners. It cannot be determined that the specific implementation of the present application is only limited to these descriptions. For those of ordinary skill in the technical field to which the present application belongs, without departing from the concept of the present application, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present application.

Claims

1. A surface treatment process for electrolytic copper foil, used for preparing electrolytic copper foil, characterized in that, It includes the following processes: unrolling the copper foil, pickling, roughening I, curing I, roughening II, curing II, roughening III, curing III, water washing I, ashing I, water washing II, ashing II, water washing III, passivation, water washing IV, water washing V, spraying silane, drying, inspection, and winding up. Among them, the process conditions for ashing I are as follows: the temperature of the ashing tank solution is 20°C - 35°C, the zinc ion concentration is 3.0 - 5.0 g / L, the nickel ion concentration is 1.5 - 2.5 g / L, the potassium pyrophosphate concentration is 100 - 120 g / L, the pH value is 9.5 - 10.5, the inlet liquid flow rate is 3 - 8 m 3 / h, the current density at the inlet liquid end is 3 - 5 A / dm 2 , and the current density at the outlet liquid end is 2 - 3 A / dm 2 ; The process conditions of the second ashing are as follows: the temperature of the ashing tank solution is 20°C - 35°C, the zinc ion concentration is 4 - 6 g / L, the nickel ion concentration is 1.0 - 1.5 g / L, the potassium pyrophosphate concentration is 100 - 120 g / L, the pH value is 9.0 - 9.5, the inlet liquid flow rate is 3 - 8 m 3 / h, and the current density at the inlet liquid end is 3 - 5 A / dm 2 , and the current density at the outlet liquid end is 2 - 3 A / dm 2 .

2. The surface treatment process of the electrolytic copper foil according to claim 1, wherein The thickness of the electrolytic copper foil is 70 μm to 105 μm. The process conditions of the roughening I, the roughening II, and the roughening III are as follows: the solution compositions in the roughening I tank, the roughening II tank, and the roughening III tank are all copper ion concentration of 9 - 15 g / L, sulfuric acid concentration of 150 - 180 g / L, inlet liquid flow rate of 5 - 8 m 3 / h, inlet end current density of 10 - 45 A / dm 2 , outlet end current density of 10 - 30 A / dm 2 , and solution temperature of 20°C - 30°C; The process conditions of the first curing, the second curing, and the third curing are as follows: The solution configurations in the first curing tank, the second curing tank, and the third curing tank all have a copper ion concentration of 40 to 60 g / L, a sulfuric acid concentration of 80 to 100 g / L, a liquid inlet flow rate of 5 to 10 m 3 / h, a current density at the liquid inlet end of 10 to 50 A / dm 2 and a current density at the liquid outlet end of 10 to 35 A / dm 2 , and the solution temperature is 30°C to 50°C; The process conditions of the first water wash, the second water wash, the third water wash, the fourth water wash and the fifth water wash are as follows: the solutions in the first water wash tank, the second water wash tank, the third water wash tank, the fourth water wash tank and the fifth water wash tank are all composed of deionized water, the inlet liquid flow rate is 3-5 m 3 / h, the pH value is 5-7.0, and the water wash temperature is 20°C-25°C; The process conditions for passivation are as follows: the temperature of the passivation tank solution is 20°C to 35°C, the concentration of hexavalent chromium ions is 2.0 to 3.0 g / L, the pH value is 10.0 to 11.0, the inlet liquid flow rate is 3 to 8 m 3 / h, the current density at the inlet end is 3 to 5 A / dm 2 , and the current density at the outlet end is 2 to 3 A / dm 2 ; The process of spraying silane is as follows: spraying a silane coupling agent with a concentration of 1 to 3 wt% on the surface of the copper foil, at a temperature of 20°C to 35°C, and a spraying flow rate of 2000 ml / min.

3. The surface treatment process of the electrolytic copper foil according to claim 2, wherein, The process conditions for both Ashing I and Ashing II are as follows: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.0 g / L, the nickel ion concentration is 2.0 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 ; The process of spraying silane is as follows: spraying a 2 wt% γ-aminopropyltriethoxysilane solution on the surface of the copper foil, at a temperature of 25°C, and a spraying flow rate of 2000 ml / min.

4. The surface treatment process of the electrolytic copper foil according to claim 2, characterized in that, The process conditions of the first ashing are as follows: the temperature of the ashing tank solution is 35 °C, the zinc ion concentration is 4.5 g / L, the nickel ion concentration is 1.6 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.5, the incoming liquid flow rate is 5 m 3 / h, the current density at the incoming liquid end is 5 A / dm 2 , and the current density at the outgoing liquid end is 3 A / dm 2 ; The process conditions of ashing II are as follows: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 5.5 g / L, the nickel ion concentration is 1.2 g / L, the potassium pyrophosphate concentration is 100 g / L, the pH value is 9.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 ; The process conditions for spraying silane are as follows: coating a 2 wt% 3-glycidoxypropyltrimethoxysilane solution on the surface of the copper foil, at a temperature of 25°C, and a spraying flow rate of 2000 ml / min.

5. The surface treatment process of the electrolytic copper foil according to claim 2, wherein, The process conditions of the first ashing are as follows: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 4.5 g / L, the nickel ion concentration is 1.6 g / L, the potassium pyrophosphate concentration is 110 g / L, the pH value is 10.5, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet liquid end is 5 A / dm 2 , and the current density at the outlet liquid end is 3 A / dm 2 ; The process conditions for ashing II are as follows: the temperature of the ashing tank solution is 35°C, the zinc ion concentration is 5.5 g / L, the nickel ion concentration is 1.2 g / L, the potassium pyrophosphate concentration is 100 g / L, the pH value is 9.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 ; The process conditions for spraying silane are as follows: spraying a 2 wt% γ-aminopropyltriethoxysilane solution on the surface of the copper foil, at a temperature of 25°C, and a spraying flow rate of 2000 ml / min.

6. The surface treatment process of the electrolytic copper foil according to claim 3 or 4 or 5, characterized in that, The process conditions for passivation are as follows: the temperature of the passivation tank solution is 30°C, the concentration of hexavalent chromium ions is 2.5 g / L, the pH value is 10.0, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 5 A / dm 2 , and the current density at the outlet end is 3 A / dm 2 .

7. The surface treatment process of electrolytic copper foil according to claim 3 or 4 or 5, characterized in that, The process conditions for the first roughening, the second roughening, and the third roughening are as follows: The solution compositions in the first roughening tank, the second roughening tank, and the third roughening tank are all: the copper ion concentration is 15 g / L, the sulfuric acid concentration is 180 g / L, the inlet liquid flow rate is 5 m 3 / h, the current density at the inlet end is 45 A / dm 2 , and the current density at the outlet end is 30 A / dm 2 , and the solution temperature is 30 °C.

8. The surface treatment process of the electrolytic copper foil according to claim 3 or 4 or 5, characterized in that The process conditions for the first curing, the second curing, and the third curing are as follows: The solution compositions in the first curing tank, the second curing tank, and the third curing tank are all configured with a copper ion concentration of 55 g / L, a sulfuric acid concentration of 100 g / L, an inlet liquid flow rate of 5 m 3 / h, an inlet end current density of 50 A / dm 2 , an outlet end current density of 35 A / dm 2 , and a solution temperature of 40°C.

9. The surface treatment process of electrolytic copper foil according to claim 3 or 4 or 5, characterized in that The process conditions for the first water wash, the second water wash, the third water wash, the fourth water wash, and the fifth water wash are as follows: the solutions in the first water wash tank, the second water wash tank, the third water wash tank, the fourth water wash tank, and the fifth water wash tank are all composed of deionized water, the liquid inlet flow rate is 5 m 3 / h, the pH value is 7.0, and the water wash temperature is 25 °C.

10. An electrolytic copper foil is prepared by using the electrolytic copper foil surface treatment process described in any one of claims 1-8.

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