Copper foil alloying treatment method and soldering-resistant copper foil

Abstract

The invention discloses a copper foil alloying treatment method and a soldering-tin-resistant copper foil, and the copper foil alloying treatment method comprises the following steps: carrying out electro-deposition on a raw foil electroplating solution to obtain a raw foil; the raw foil is subjected to acid pickling, roughening and curing treatment, and an electrolytic copper foil is obtained; alloying treatment is conducted on the electrolytic copper foil through alloying electroplating liquid, and alloyed copper foil is obtained; wherein the alloying electroplating liquid comprises 70 g / L to 130 g / L of potassium pyrophosphate and 1.5 g / L to 7.5 g / L of zinc sulfate, and the alloying electroplating liquid does not contain nickel ions; and carrying out passivation treatment on the alloyed copper foil by using a passivation electroplating solution to obtain the soldering-tin-resistant copper foil. Through the method, the tin-soldering-resistant copper foil is obtained.

Description

Technical Field

[0001] The present invention relates to the field of display technology, in particular to a copper foil alloying treatment method and a solder-resistant copper foil. Background Art

[0002] With the rapid development of 5G communication, the frequency and speed of transmission signals are constantly increasing, which inevitably requires PCB circuit substrates to have good heat resistance. The large amount of heat generated by high-frequency and high-speed signals can easily cause the copper foil to peel off from the substrate in substrates with poor heat resistance, thus causing short circuits, open circuits and other problems. Therefore, improving the heat resistance of high-frequency and high-speed copper foil is an urgent issue. At the same time, it is also necessary to ensure that other important properties of copper foil meet the requirements of high-frequency and high-speed PCB substrates, such as surface roughness. In order to meet the development needs of 5G communication, the development of high-frequency and high-speed copper foil with heat resistance and roughness has become the trend of future high-end copper foil development.

[0003] The heat resistance index of PCB substrate is mainly reflected in the solder resistance of copper foil. The better the solder resistance, the better the connection strength between copper foil and substrate, and the less likely it is to peel off. Summary of the invention

[0004] The main technical problem solved by the present application is to provide a copper foil alloying treatment method and a high solder resistant copper foil in order to overcome the problems of high surface roughness, low heat resistance temperature and poor peel strength of the copper foil in the prior art.

[0005] To solve the above problems, the first aspect of the present application provides a copper foil alloying treatment method, the copper foil alloying treatment method comprising: electroplating a raw foil electroplating solution to obtain a raw foil; pickling, roughening, and curing the raw foil to obtain an electrolytic copper foil; alloying the electrolytic copper foil with an alloying electroplating solution to obtain an alloyed copper foil; wherein the alloying electroplating solution contains 70-130 g / L of potassium pyrophosphate and 1.5-7.5 g / L of zinc sulfate, and the alloying electroplating solution does not contain nickel ions; passivating the alloyed copper foil with a passivation electroplating solution to obtain a solder-resistant copper foil.

[0006] In a specific embodiment, the alloying electroplating solution is prepared from anhydrous potassium pyrophosphate, zinc sulfate and deionized water.

[0007] In a specific embodiment, the passivation plating solution is prepared from deionized water and chromic anhydride, wherein the concentration of the chromic anhydride is 1.5-12 g / L.

[0008] In a specific embodiment, in the step of alloying the electrolytic copper foil with an alloying plating solution, the temperature of the alloying treatment is 20-25°C, the upper liquid flow rate of the alloying treatment is 2-10L / min, and the current density of the alloying treatment is 0.5-5A / dm 2 The alloying treatment time is 1-18s, and the production line speed of the alloying treatment is 1-30m / min.

[0009] In a specific embodiment, in the step of passivating the electrolytic copper foil after alloying treatment with a passivation plating solution, the temperature of the passivation treatment is 20-25°C, the upper liquid flow rate of the passivation treatment is 2-10L / min, and the current density of the passivation treatment is 0.5-8A / dm 2 The passivation treatment time is 1-15s, and the production line speed of the passivation treatment is 1-30m / min.

[0010] In a specific embodiment, the raw foil electroplating solution includes copper sulfate, sulfuric acid and additives; wherein the concentration of copper sulfate is 75-115 g / L, the concentration of sulfuric acid is 90-130 g / L, and the concentration of additives is 1-20 ppm.

[0011] In a specific embodiment, in the step of electroplating the raw foil electroplating solution to obtain the raw foil, the deposition temperature of the raw foil electroplating solution is 40-55°C, the upper liquid flow rate of the raw foil electroplating solution is 35-55L / min, the production line speed of the raw foil electroplating solution is 2-15m / min, and the current density of the electroplating is 5-25A / dm 2 .

[0012] In a specific embodiment, the step of pickling, roughening and curing the raw foil to obtain copper foil includes: pickling the raw foil with a pickling electroplating solution; the pickling electroplating solution includes sulfuric acid with a concentration of 90-200 g / L; roughening the raw foil with a roughening electroplating solution; the roughening electroplating solution includes copper sulfate with a concentration of 3-20 g / L and sulfuric acid with a concentration of 100-180 g / L; curing the raw foil with a curing electroplating solution; the curing electroplating solution includes copper sulfate with a concentration of 35-58 g / L and sulfuric acid with a concentration of 90-150 g / L.

[0013] In a specific embodiment, in the step of roughening the raw foil with a roughening plating solution, the roughening treatment temperature is 25-35°C, the upper liquid flow rate is 1-10L / min, the production line speed is 1-30m / min, and the current density is 5-35A / dm 2In the step of roughening the raw foil with the roughening plating solution, the curing temperature is 25-50°C, the upper liquid flow rate is 1-10L / min, the production line speed is 1-30m / min, and the current density is 5-35A / dm 2 .

[0014] To solve the above problems, the second aspect of the present application provides a solder-resistant copper foil, wherein the surface roughness of the solder-resistant copper foil is not greater than 15 μm, the peel strength after baking at 177°C for 24 hours is not less than 0.5 N / mm, and the peel strength attenuation rate after tinning at 288°C for 5 minutes is not greater than 40%.

[0015] The beneficial effects of the present application are as follows: the alloying electroplating solution provided in the present invention is used in the preparation of solder-resistant copper foil, which can not only prevent the copper foil from being oxidized and discolored at high temperatures, resulting in a decrease in conductivity, but also enable the copper foil to have a smaller (tin immersion) attenuation rate, thereby enhancing the connection strength between the copper foil and the substrate at high temperatures and avoiding falling off; and the alloying process is simple, the electroplating solution contains fewer metal elements, and the degree of metal contamination is low, and the method does not contain nickel and does not produce ferromagnetism, and the obtained copper foil has better solder resistance and is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic flow chart of an embodiment of a copper foil alloying treatment method provided in the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "said", and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless otherwise clearly indicated above, and "multiple" generally includes at least two, but does not exclude the inclusion of at least one.

[0020] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0021] It should be understood that the terms "include", "comprises" or any other variations used herein are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "includes..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0022] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The presence of the phrase at each location in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] The present application provides an alloying plating solution, which includes 70-130g / L potassium pyrophosphate and 1.5-7.5g / L zinc sulfate. Specifically, the alloying plating solution is prepared from anhydrous potassium pyrophosphate, zinc sulfate and deionized water, that is, the alloying plating solution is only composed of anhydrous potassium pyrophosphate, zinc sulfate and deionized water. The specific preparation process includes: using deionized water as a basic solvent, adding anhydrous potassium pyrophosphate and zinc sulfate to deionized water in proportion to prepare an alloying plating solution containing 70-130g / L potassium pyrophosphate and 1.5-7.5g / L zinc sulfate. The alloying plating solution includes potassium ions, phosphate ions, sulfate ions and zinc ions, etc.

[0025] The alloying electroplating solution is used in the alloying treatment of copper foil.

[0026] This application provides a copper foil alloying treatment method. Figure 1 , Figure 1 This is a schematic diagram of a process of an embodiment of the copper foil alloying treatment method of the present application. Figure 1 As shown, the processing method includes:

[0027] Step S11: Electrodepositing the raw foil electroplating solution to obtain the raw foil.

[0028] The green foil electroplating solution is electroplated on the cathode roller to obtain the green foil. In other words, the green foil electroplating solution is electroplated by the cathode roller to generate the green foil.

[0029] Specifically, the raw foil electroplating solution includes copper sulfate, sulfuric acid and additives, etc. Among them, the concentration of copper sulfate is preferably 75-115 g / L, the concentration of sulfuric acid (H2SO4) is preferably 90-130 g / L, and the concentration of additives is preferably 1-20 ppm.

[0030] Step S11 specifically includes placing the cathode roller in an electrolytic cell, the electrolytic cell is filled with raw foil electroplating solution, one end of the cathode roller is externally connected to a circuit, and power is applied to generate raw foil by deposition. The electrolytic cell is also provided with a flow control device for controlling the liquid feeding speed of the electrolytic cell. The liquid feeding speed is also called the circulation flow rate of the electroplating solution in the electrolytic cell, wherein the liquid feeding flow rate can ensure the provision of sufficient plating solution and the uniformity of the copper foil.

[0031] In step S11, the temperature of the raw foil electroplating solution deposition / electroplating treatment is 40-50°C, the upper liquid flow rate is 35-55L / min, the production line speed is 2-15m / min, and the current density is 5-25A / dm 2 .

[0032] It should be noted that the upper liquid flow rate is the amount of liquid entering the electrolytic cell per minute or the flow rate of raw foil plating solution flowing to the plating cell per minute. The upper liquid flow rate controls the stability of the plating solution and the condition of the foil surface. The production line speed refers to the rotation speed of the cathode roller, and the thickness of the alloy foil layer is controlled by the cathode roller line speed. The current density refers to the current density on the cathode roller, and the current density of the cathode roller is controlled by adjusting the current size. These parameters determine the thickness and quality of the generated raw foil.

[0033] Step S12: pickling, roughening and curing the raw foil to obtain electrolytic copper foil.

[0034] Specifically, the process includes pickling the raw foil with a pickling electroplating solution, roughening the raw foil with a roughening electroplating solution, and curing the raw foil with a fixing electroplating solution. This step includes but is not limited to three roughening and three curing processes and multiple pickling processes, which are not limited here.

[0035] In this embodiment, the pickling solution is a sulfuric acid solution, the roughening electroplating solution is a mixed solution of sulfuric acid and copper sulfate, and the solidification electroplating solution is a mixed solution of copper sulfate and sulfuric acid. The concentration of sulfuric acid in the pickling electroplating solution is 90-200 g / L. The concentration of copper sulfate in the roughening electroplating solution is 3-20 g / L, and the concentration of sulfuric acid is 90-200 g / L. The concentration of copper sulfate in the solidification electroplating solution is 35-58 g / L, and the concentration of sulfuric acid is 90-150 g / L.

[0036] Furthermore, in the step of roughening the raw foil with the roughening plating solution, the roughening temperature (i.e., the reaction temperature during the roughening process) is 25-35°C, the upper liquid flow rate of the roughening process is 1-10L / min, the production line speed of the roughening process is 1-30m / min, and the current density of the roughening process is 5-35A / dm 2 The roughening treatment specifically involves placing the raw foil into a plating tank filled with a roughening plating solution for roughening treatment, the liquid flow rate is the amount of liquid entering the plating tank per minute, the production speed is the reaction speed per minute, and the current density is the reaction current density per unit area on the raw foil.

[0037] In the step of curing the raw foil with the curing plating solution, the curing temperature is 25-50°C, the upper liquid flow rate of the curing is 1-10L / min, the production line speed of the curing is 1-30m / min, and the current density of the curing is 5-35A / dm 2 .

[0038] The electrolytic copper foil is produced through the above steps.

[0039] Step S13: alloying the electrolytic copper foil with an alloying plating solution to obtain an alloyed copper foil.

[0040] In this embodiment, the electrolytic copper foil obtained in the above steps S11-S12 is alloyed to obtain an alloyed copper foil through the performance of the electrolytic copper foil (including solder resistance). The alloyed copper foil may specifically refer to a copper foil having an alloying layer formed on the surface of the electrolytic copper foil. The essence of the alloying treatment is to form a chemical bond between metals, and the solder resistance of the copper foil can be improved by the alloying treatment.

[0041] In the present embodiment, the alloying plating solution contains 70-130g / L of potassium pyrophosphate and 1.5-7.5g / L of zinc sulfate. It should be noted that the alloying plating solution does not contain nickel ions. Specifically, the alloying plating solution is prepared by anhydrous potassium pyrophosphate, zinc sulfate and deionized water, that is, the alloying plating solution is only composed of anhydrous potassium pyrophosphate, zinc sulfate and deionized water. The specific preparation process includes: using deionized water as a basic solvent, anhydrous potassium pyrophosphate and zinc sulfate are added to deionized water in proportion to be prepared into an alloying plating solution containing 70-130g / L of potassium pyrophosphate and 1.5-7.5g / L of zinc sulfate. In other words, the alloying plating solution includes potassium ions, phosphate ions, sulfate ions and zinc ions, but does not contain nickel ions.

[0042] In this embodiment, the alloying electroplating solution contains fewer metal elements and a low degree of metal contamination. Furthermore, the alloying electroplating solution does not contain nickel and will not produce ferromagnetism. The resulting copper foil also has better solder resistance.

[0043] Furthermore, the temperature of the alloying treatment is room temperature (20-25°C), the flow rate of the upper liquid of the alloying treatment is 2-10L / min, and the current density of the alloying treatment is 0.5-5A / dm 2 The alloying treatment time is 1-18s, and the production line speed of the alloying treatment is 1-30m / min.

[0044] Step S14: passivating the alloyed copper foil using a passivation plating solution to obtain a solder-resistant copper foil.

[0045] Among them, solder-resistant copper foil refers to copper foil that has better solder resistance than general copper foil.

[0046] The passivation treatment process in step S14 specifically includes forming a barrier layer (or passivation layer) on one or more sides of the alloyed copper foil to prevent oxidation of the copper foil.

[0047] The passivation plating solution is composed of deionized water and chromic anhydride, and the concentration of chromic anhydride is 1.5-12g / L.

[0048] Furthermore, the temperature of the passivation treatment is 20-25°C, the flow rate of the upper liquid of the passivation treatment is 2-10L / min, and the current density of the passivation treatment is 0.5-8A / dm 2 The passivation treatment time is 1-15s, and the passivation treatment line speed is 1-30m / min.

[0049] In this embodiment, the electrolytic copper foil is alloyed using a nickel-free alloying plating solution in step S13, so that the obtained copper foil does not produce ferromagnetism and has excellent performance, thereby improving the solder resistance of the copper foil and further improving the heat resistance of the PCB substrate.

[0050] The beneficial effects of this embodiment include: 1. The green foil electroplating solution is stable, ensuring that the roughness of the generated green foil is uniform; 2. The alloying process is simple and easy to realize industrialization; 3. The obtained copper foil has good solder resistance.

[0051] The present application also provides a solder-resistant copper foil, which is prepared by the above method. The thickness of the solder-resistant copper foil is between 6 and 70 μm, the surface roughness of the solder-resistant copper foil is Rz ≤ 15 μm, the peel strength TG140 after baking at 177°C for 24 hours is ≥ 0.5 N / mm, and the peel strength attenuation rate (TG170) after tinning at 288°C for 5 minutes is ≤ 40%.

[0052] In a preferred embodiment, the thickness of the solder-resistant copper foil is 35 μm, the surface roughness Rz of the solder-resistant copper foil is 4.89 μm, the peel strength after baking at 177°C for 24 hours is TG140=1.61 N / mm, and the peel strength attenuation rate (TG170) after tinning at 288°C for 5 minutes is 15%.

[0053] Among them, TG140 and TG170 refer to substrate boards.

[0054] The roughness Rz is tested using a roughness meter in accordance with GBT5230-2020.

[0055] Peel strength test method: The solder-resistant copper foil was pressed onto the TG140 substrate, and after baking at 177°C for 24 hours, the peel strength test was performed using an anti-peel tester.

[0056] Attenuation rate (tin immersion) test method: Press the solder-resistant copper foil onto the TG140 substrate, then place the sample in molten tin at 288°C for 5 minutes, then take it out and use an anti-peel tester to test the peel strength to obtain the peel strength value after tin immersion; then use the peel strength value after tin immersion and the peel strength test result without tin immersion to calculate the attenuation rate. The specific calculation formula is: (peel strength without tin immersion - peel strength after tin immersion at 288°C) / peel strength without tin immersion.

[0057] In this embodiment, the surface of the solder-resistant copper foil contains a modified metal, which contains zinc and potassium but does not contain nickel, and is evenly distributed on the surface of the copper foil.

[0058] The present invention will be described in detail below through examples. The alloying electroplating solution contains potassium ions, phosphate ions, zinc ions and sulfate ions.

[0059] Example 1

[0060] A raw foil electroplating solution was prepared with a copper sulfate concentration of 95 g / L, a sulfuric acid (H2SO4) concentration of 110 g / L, and an additive concentration of 10 ppm.

[0061] The above-mentioned raw foil electroplating solution is placed in an electrolytic cell, with a pure copper plate as an anode plate and a titanium plate as a cathode plate, and electroplating is performed at a temperature of 40-50°C to obtain raw foil; wherein, the upper liquid flow rate is 45L / min, the production line speed is 8m / min, and the current density is 15A / dm 2 .

[0062] A pickling electroplating solution having a sulfuric acid concentration of 150 g / L was prepared.

[0063] The raw foil is placed in an acid pickling electroplating solution and pickled at room temperature (25-35° C.).

[0064] A roughening electroplating solution was prepared with a copper sulfate concentration of 11 g / L and a sulfuric acid concentration of 150 g / L.

[0065] The pickled raw foil is placed in a roughening electroplating solution and roughened at room temperature (25-35°C); wherein the upper liquid flow rate of the roughening treatment is 5 L / min, the production line speed of the roughening treatment is 15 m / min, and the current density of the roughening treatment is 20 A / dm 2 .

[0066] A solidified electroplating solution was prepared with a copper sulfate concentration of 11.5 g / L and a sulfuric acid concentration of 120 g / L.

[0067] The roughened raw foil is placed in a curing electroplating solution and cured at 25-50°C to obtain an electrolytic copper foil. The curing liquid flow rate is 5L / min, the curing line speed is 15m / min, and the curing current density is 20A / dm 2 .

[0068] Using deionized water as a basic solvent, anhydrous potassium pyrophosphate and zinc sulfate are dissolved in the deionized water and mixed evenly to obtain an alloying electroplating solution with a potassium pyrophosphate concentration of 100 g / L and a zinc ion concentration of 4.5 g / L.

[0069] The electrolytic copper foil is placed in an alloying plating solution and alloyed at room temperature (20-25°C) to obtain an alloyed copper foil. The upper liquid flow rate of the alloying treatment is 5L / min, and the current density of the alloying treatment is 3A / dm 2 The alloying treatment time is 9s, and the production line speed of the alloying treatment is 15m / min.

[0070] Chromic anhydride was dissolved in deionized water and mixed evenly to obtain a passivation electroplating solution with a passivation chromic anhydride concentration of 6.5 g / L.

[0071] The alloyed copper foil is placed in a passivation plating solution and passivated at room temperature (20-25°C) to obtain a solder-resistant copper foil. The upper liquid flow rate of the passivation treatment is 6L / min, and the current density of the passivation treatment is 4A / dm 2 The passivation treatment time is 8s, and the passivation treatment line speed is 15m / min.

[0072] The properties of the obtained solder resistant copper foil are shown in the following table:

[0073]

[0074] Among them, the resist surface refers to the surface of the solder-resistant copper foil used for welding, and the pressing surface refers to the surface of the solder-resistant copper foil used for pressing. The tin-stripping resistance refers to the peeling strength after immersion in tin at 288℃ for 5 minutes or 10 minutes. JIS-1994 is a roughness standard.

[0075] From the above table, it can be seen that the roughness of the solder-resistant copper foil is not greater than 15μm, the peeling strength is not less than 0.5N / mm, and the attenuation rate of the tin-bleaching resistance is not greater than 40%. Therefore, the above alloying treatment can produce a solder-resistant copper foil with small roughness, good high temperature resistance, and high bonding strength, which can also withstand high temperatures.

[0076] Example 2

[0077] The parameters in Example 2 are the same as those in Example 1, except that the concentration ratio of potassium pyrophosphate concentration and zinc sulfate concentration in the alloying plating solution is different. The potassium pyrophosphate concentration in the alloying plating solution in Example 2 is 70 g / L, and the zinc ion concentration is 4.5 g / L. The properties of the solder-resistant copper foil obtained by alloying treatment using the above alloying plating solution are shown in the following table:

[0078]

[0079] Example 3

[0080] The parameters in Example 3 are the same as those in Example 1, except that the concentration ratio of potassium pyrophosphate concentration and zinc sulfate concentration in the alloying plating solution is different. The potassium pyrophosphate concentration in the alloying plating solution in Example 3 is 130 g / L, and the zinc ion concentration is 4.5 g / L. The properties of the solder-resistant copper foil obtained by alloying treatment using the above alloying plating solution are shown in the following table:

[0081]

[0082] Example 4

[0083] The parameters in Example 4 are the same as those in Example 1, except that the concentration ratio of potassium pyrophosphate concentration and zinc sulfate concentration in the alloying electroplating solution is different. The potassium pyrophosphate concentration in the alloying electroplating solution in Example 4 is 70 g / L, and the zinc ion concentration is 1.5 g / L. The properties of the solder-resistant copper foil obtained by alloying treatment using the above alloying electroplating solution are shown in the following table:

[0084]

[0085]

[0086] Example 5

[0087] The parameters in Example 5 are the same as those in Example 1, except that the concentration ratio of potassium pyrophosphate concentration and zinc sulfate concentration in the alloying electroplating solution is different. The potassium pyrophosphate concentration in the alloying electroplating solution in Example 5 is 70 g / L, and the zinc ion concentration is 7.5 g / L. The properties of the solder-resistant copper foil obtained by alloying treatment using the above alloying electroplating solution are shown in the following table:

[0088]

[0089]

[0090] Comparative Example 6

[0091] The parameters in Comparative Example 6 are the same as those in Example 1, except that the alloying plating solution contains nickel ions. The concentration of potassium pyrophosphate in the alloying plating solution in Example 6 is 70 g / L, the concentration of zinc ions is 4.5 g / L, and the concentration of nickel ions is 85 ppm. The properties of the solder-resistant copper foil obtained by alloying with the alloying plating solution are shown in the following table:

[0092]

[0093] Comparison between Example 1 and Comparative Example 6 shows that, under the same substrate (TG140 / TG170), the peeling strength in Example 1 is greater than the peeling strength in Comparative Example 6, and under the same rinsing time (5min / 10min), the tin stripping resistance in Example 1 is also better than the tin stripping resistance with nickel ions added in Comparative Example 6. Therefore, the solder resistance of the copper foil treated with the alloying plating solution without nickel ions is better than the solder resistance of the copper foil treated with the alloying plating solution with nickel ions added.

[0094] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A copper foil alloying treatment method, characterized in that: include: Electrodepositing a raw foil electroplating solution to obtain a raw foil; The raw foil is pickled, roughened and cured to obtain an electrolytic copper foil; The electrolytic copper foil is alloyed by using an alloying electroplating solution to obtain an alloyed copper foil; wherein the alloying electroplating solution contains 70-130 g / L of potassium pyrophosphate and 1.5-7.5 g / L of zinc sulfate, and the alloying electroplating solution does not contain nickel ions; The alloyed copper foil is passivated by using a passivation plating solution to obtain a solder-resistant copper foil.

2. The copper foil alloying treatment method according to claim 1, characterized in that: The alloying electroplating solution is prepared from anhydrous potassium pyrophosphate, zinc sulfate and deionized water.

3. The copper foil alloying treatment method according to claim 1, characterized in that: The passivation plating solution is prepared from deionized water and chromic anhydride, wherein the concentration of the chromic anhydride is 1.5-12 g / L.

4. The copper foil alloying treatment method according to claim 1, characterized in that: In the step of alloying the electrolytic copper foil with an alloying plating solution, the temperature of the alloying treatment is 20-25°C, the upper liquid flow rate of the alloying treatment is 2-10L / min, and the current density of the alloying treatment is 0.5-5A / dm 2 The alloying treatment time is 1-18s, and the production line speed of the alloying treatment is 1-30m / min.

5. The copper foil alloying treatment method according to claim 1, characterized in that: In the step of passivating the electrolytic copper foil after alloying treatment with a passivation plating solution, the temperature of the passivation treatment is 20-25°C, the upper liquid flow rate of the passivation treatment is 2-10L / min, and the current density of the passivation treatment is 0.5-8A / dm 2 The passivation treatment time is 1-15s, and the production line speed of the passivation treatment is 1-30m / min.

6. The solder-resistant high-frequency and high-speed copper foil alloying treatment method according to claim 1, characterized in that: The raw foil electroplating solution comprises copper sulfate, sulfuric acid and additives; wherein the concentration of the copper sulfate is 75-115 g / L, the concentration of the sulfuric acid is 90-130 g / L, and the concentration of the additive is 1-20 ppm.

7. The copper foil alloying treatment method according to claim 6, characterized in that: In the step of electroplating the raw foil electroplating solution to obtain the raw foil, the deposition temperature of the raw foil electroplating solution is 40-55°C, the upper liquid flow rate of the raw foil electroplating solution is 35-55L / min, the production line speed of the raw foil electroplating solution is 2-15m / min, and the current density of the electroplating is 5-25A / dm 2 .

8. The copper foil alloying treatment method according to claim 1, characterized in that: The step of pickling, roughening and curing the raw foil to obtain the copper foil comprises: The raw foil is pickled using a pickling electroplating solution; the pickling electroplating solution comprises sulfuric acid with a concentration of 90-200 g / L; The raw foil is roughened by using a roughening electroplating solution; the roughening electroplating solution comprises copper sulfate with a concentration of 3-20 g / L and sulfuric acid with a concentration of 100-180 g / L; The raw foil is cured by using a curing electroplating solution; the curing electroplating solution comprises copper sulfate with a concentration of 35-58 g / L and sulfuric acid with a concentration of 90-150 g / L.

9. The copper foil alloying treatment method according to claim 8, characterized in that: In the step of roughening the raw foil with a roughening plating solution, the roughening treatment temperature is 25-35°C, the upper liquid flow rate is 1-10L / min, the production line speed is 1-30m / min, and the current density is 5-35A / dm 2 ; In the step of roughening the raw foil with the roughening plating solution, the curing temperature is 25-50°C, the upper liquid flow rate is 1-10L / min, the production line speed is 1-30m / min, and the current density is 5-35A / dm 2 .

10. A solder-resistant copper foil, characterized in that: The surface roughness of the solder-resistant copper foil is not greater than 15 μm, the peel strength after baking at 177° C. for 24 hours is not less than 0.5 N / mm, and the peel strength attenuation rate after tinning at 288° C. for 5 minutes is not greater than 40%.

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